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                                                                   EXHIBIT 10.15


                             MASTER LEASE AGREEMENT


MASTER LEASE AGREEMENT (the "Master Lease") dated January 15, 1999 by and
between COMDISCO, INC. ("Lessor") and PLANETRX, INC. ("Lessee").

IN CONSIDERATION of the mutual agreements described below, the parties agree as
follows (all capitalized terms are defined in Section 14.18):

1. PROPERTY LEASED.

Lessor leases to Lessee all of the Equipment described on each Summary Equipment
Schedule. In the event of a conflict, the terms of the applicable Schedule
prevail over this Master Lease.

2. TERM.

On the Commencement Date, Lessee will be deemed to accept the Equipment, will be
bound to its rental obligations for each item of Equipment and the term of a
Summary Equipment Schedule will begin and continue through the Initial Term and
thereafter until terminated by either party upon prior written notice received
during the Notice Period. No termination may be effective prior to the
expiration of the Initial Term.

3. RENT AND PAYMENT.

Rent is due and payable in advance on the first day of each Rent Interval at the
address specified in Lessor's invoice. Interim Rent is due and payable when
invoiced. If any payment is not made when due, Lessee will pay a Late Charge on
the overdue amount. Upon Lessee's execution of each Schedule, Lessee will pay
Lessor the Advance specified on the Schedule. The Advance will be credited
towards the final Rent payment if Lessee is not then in default. No interest
will be paid on the Advance.

4. SELECTION; WARRANTY AND DISCLAIMER OF WARRANTIES.

4.1 SELECTION. Lessee acknowledges that it has selected the Equipment and
disclaims any reliance upon statements made by the Lessor, other than as set
forth in the Schedule.

4.2 WARRANTY AND DISCLAIMER OF WARRANTIES. Lessor warrants to Lessee that, so
long as Lessee is not in default, Lessor will not disturb Lessee's quiet and
peaceful possession, and unrestricted use of the Equipment. To the extent
permitted by the manufacturer, Lessor assigns to Lessee during the term of the
Summary Equipment Schedule any manufacturer's warranties for the Equipment.
LESSOR MAKES NO OTHER WARRANTY, EXPRESS OR IMPLIED AS TO ANY MATTER WHATSOEVER,
INCLUDING, WITHOUT LIMITATION, THE MERCHANTABILITY OF THE EQUIPMENT OR ITS
FITNESS FOR A PARTICULAR PURPOSE. Lessor is not responsible for any liability,
claim, loss, damage or expense of any kind (including strict liability in tort)
caused by the Equipment except for any loss or damage caused by the willful
misconduct or negligent acts of Lessor. In no event Is Lessor responsible for
special, incidental or consequential damages.

5. TITLE; RELOCATION OR SUBLEASE; AND ASSIGNMENT.

5.1 TITLE. Lessee holds the Equipment subject and subordinate to the rights of
the Owner, Lessor, any Assignee and any Secured Party. Lessee authorizes Lessor,
as Lessee's agent, and at Lessor's expense, to prepare, execute and file in
Lessee's name precautionary Uniform Commercial Code financing statements showing
the interest of the Owner, Lessor, and any Assignee or Secured Party in the
Equipment and to insert serial numbers in Summary Equipment Schedules as
appropriate. Lessee will, at its expense, keep the Equipment free and clear from
any liens or encumbrances of any kind (except any caused by Lessor) and will
indemnify and hold the Owner, Lessor, any Assignee and Secured Party harmless
from and against any loss caused by Lessee's failure to do so, except where such
is caused by Lessor.

5.2 RELOCATION OR SUBLEASE. Upon prior written notice, Lessee may relocate
Equipment to any location within the continental United States provided (i) the
Equipment will not be used by an entity exempt from federal income tax, and (ii)
all additional costs (including any administrative fees, additional taxes and
insurance coverage) are reconciled and promptly paid by Lessee.

Lessee may sublease the Equipment upon the reasonable consent of the Lessor and
the Secured Party. Such consent to sublease will be granted if: (i) Lessee meets
the relocation requirements set out above, (ii) the sublease is expressly
subject and subordinate to the terms of the Schedule, (iii) Lessee assigns its
rights in the sublease to Lessor and the Secured Party as additional collateral
and security, (iv) Lessee's obligation to maintain and insure the Equipment is
not altered, (v) all financing statements required to continue the Secured
Party's prior perfected security interest are filed, and (vi) Lessee executes
sublease documents acceptable to Lessor.

No relocation or sublease will relieve Lessee from any of its obligations under
this Master Lease and the relevant Schedule.

5.3 ASSIGNMENT BY LESSOR. The terms and conditions of each Schedule have been
fixed by Lessor in order to permit Lessor to sell and/or assign or transfer its
interest or grant a security interest in each Schedule and/or the Equipment to a
Secured Party or Assignee. In that event, the term Lessor will mean the Assignee
and any Secured Party. However, any assignment, sale, or other transfer by
Lessor will not relieve Lessor of its obligations to Lessee and will not
materially change Lessee's duties or materially increase the burdens or risks
imposed on Lessee. The Lessee consents to and will acknowledge such assignments
in a written notice given to Lessee. Lessee also agrees that:

(a)      The Secured Party will be entitled to exercise all of Lessor's rights,
but will not be obligated to perform any of the obligations of Lessor. The
Secured Party will not disturb Lessee's quiet and peaceful possession and
unrestricted use of the Equipment so long as Lessee is not in default and the
Secured Party continues to receive all Rent payable under the Schedule; and

(b)      Lessee will pay all Rent and all other amounts payable to the Secured
Party, despite any defense or claim which it has against Lessor. Lessee reserves
its right to have recourse directly against Lessor for any defense or claim;

(c)      Subject to and without impairment of Lessee's leasehold rights in the
Equipment, Lessee holds the Equipment for the Secured Party to the extent of the
Secured Party's rights in that Equipment.

6. NET LEASE; TAXES AND FEES.

6.1 NET LEASE. Each Summary Equipment Schedule constitutes a net lease. Lessee's
obligation to pay Rent and all other amounts due hereunder is absolute and
unconditional and is not subject to any abatement, reduction, set-off, defense,
counterclaim, interruption, deferment or recoupment for any reason whatsoever.

6.2 TAXES AND FEES. Lessee will pay when due or reimburse Lessor for all taxes,
fees or any other charges (together with any related interest or penalties not
arising from the negligence of Lessor) accrued for or arising during the term of
each Summary Equipment Schedule against Lessor, Lessee or the Equipment by any
governmental authority (except only Federal, state, local and franchise taxes on
the capital or the net income of Lessor). Lessor will file all personal property
tax returns for the Equipment and pay all such property taxes due. Lessee will
reimburse Lessor for property taxes within thirty (30) days of receipt of an
invoice.

7. CARE, USE AND MAINTENANCE; INSPECTION BY LESSOR.

7.1 CARE, USE AND MAINTENANCE. Lessee will maintain the Equipment in good
operating order and appearance, protect the Equipment from deterioration, other
than normal wear and tear, and will not use the Equipment for any purpose other
than that for which it was designed. If commercially available and considered
common business practice for each item of Equipment, Lessee will maintain in
force a standard maintenance contract with the manufacturer of the Equipment, or
another party acceptable to Lessor, and will provide Lessor with a complete copy
of that contract. If Lessee has the Equipment maintained by a party other than
the manufacturer or self maintains. Lessee agrees to pay any costs necessary for
the manufacturer to bring the Equipment to then current release, revision and
engineering change levels, and to re-certify the Equipment as eligible for
manufacturer's maintenance at the expiration of the lease term, provided
re-certification is available and is required by Lessor. The lease term will
continue upon the same terms and conditions until recertification has been
obtained.

7.2 INSPECTION BY LESSOR. Upon reasonable advance notice, Lessee, during
reasonable business hours and subject to Lessee's security requirements, will
make the Equipment and its related log and maintenance records available to
Lessor for inspection.

8. REPRESENTATIONS AND WARRANTIES OF LESSEE. Lessee hereby represents, warrants
and covenants that with respect to the Master Lease end each Schedule executed
hereunder.

(a)      The Lessee is a corporation duly organized and validly existing in good
standing under the laws of the jurisdiction of its incorporation, is duly
qualified to do business in each jurisdiction (including the jurisdiction where
the Equipment is, or is to be, located) where its ownership or lease of property
or the conduct of its business requires such qualification, except for where
such lack of qualification would not have a material adverse effect on the
Company's business; and has full corporate power and authority to hold property
under the Master Lease and each Schedule and to enter into and perform its
obligations under the Master Lease and each Schedule.


(b)      The execution and delivery by the Lessee of the Master Lease and each
Schedule and its performance thereunder have been duly authorized by all
necessary corporate action on the part of the Lessee, and the Master Lease and
each Schedule are not inconsistent with the Lessee's Articles of Incorporation
or Bylaws, do not contravene any law or governmental rule, regulation or order
applicable to it, do not and will not contravene any provision of, or constitute
a default under, any indenture, mortgage, contract or other instrument to which
it is a party or by which it is bound, and the Master Lease and each Schedule
constitute legal, valid and binding agreements of the Lessee, enforceable in
accordance with their terms, subject to the effect of applicable bankruptcy and
other similar laws affecting the rights of creditors generally and rules of law
concerning equitable remedies.


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(c)      There are no actions, suits, proceedings or patent claims pending or,
to the knowledge of the Lessee, threatened against or affecting the Lessee in
any court or before any governmental commission, board or authority which, if
adversely determined, will have a material adverse effect on the ability of the
Lessee to perform its obligations under the Master Lease and each Schedule.

(d)      The Equipment is personal property and when subjected to use by the
Lessee will not be or become fixtures under applicable law.

(e)      The Lessee has no material liabilities or obligations, absolute or
contingent (individually or in the aggregate), except the liabilities and
obligations of the Lessee as set forth in the Financial Statements and
liabilities and obligations which have occurred in the ordinary course of
business, and which have not been, in any case or in the aggregate, materially
adverse to Lessee's ongoing business.

(f)      To the best of the Lessee's knowledge, the Lessee owns, possesses, has
access to, or can become licensed on reasonable terms under all patents, patent
applications, trademarks, trade names, inventions, franchises, licenses,
permits, computer software and copyrights necessary for the operations of its
business as now conducted, with no known infringement of, or conflict with, the
rights of others.

(g)      All material contracts, agreements and instruments to which the Lessee
is a party are in full force and effect in all material respects, and are valid,
binding and enforceable by the Lessee in accordance with their respective terms,
subject to the effect of applicable bankruptcy and other similar laws affecting
the rights of creditors generally, and rules of law concerning equitable
remedies.

9. DELIVERY AND RETURN OF EQUIPMENT

Lessee hereby assumes the full expense of transportation and in-transit
insurance to Lessee's premises and installation thereat of the Equipment. Upon
termination (by expiration or otherwise) of each Summary Equipment Schedule,
Lessee shall, pursuant to Lessor's instructions and at Lessee's full expense
(including, without limitation, expenses of transportation and in-transit
insurance), return the Equipment to Lessor in the same operating order, repair,
condition and appearance as when received, less normal depreciation and wear and
tear. Lessee shall return the Equipment to Lessor at 6111 North River Road,
Rosemont, Illinois 60018 or at such other address within the continental United
Stales as directed by Lessor, provided, however, that Lessee's expense shall be
limited to the cost of returning the Equipment to Lessor's address as set forth
herein. During the period subsequent to receipt of a notice under Section 2,
Lessor may demonstrate the Equipment's operation in place and Lessee will supply
any of its personnel as may reasonably be required to assist in the
demonstrations.

10. LABELING.

Upon request, Lessee will mark the Equipment indicating Lessor's interest with
labels provided by Lessor. Lessee will keep all Equipment free from any other
marking or labeling which might be interpreted as a claim of ownership.

11. INDEMNITY.

With regard to bodily injury end property damage liability only, Lessee will
indemnify and hold Lessor, any Assignee end any Secured Party harmless from and
against any and all claims, costs, expenses, damages and liabilities, including
reasonable attorneys' fees, arising out of the ownership (for strict liability
in tort only), selection, possession, leasing, operation, control, use,
maintenance, delivery, return or other disposition of the Equipment during the
term of this Master Lease or until Lessee's obligations under the Master Lease
terminate. However, Lessee is not responsible to a party indemnified hereunder
for any claims, costs, expenses, damages and liabilities occasioned by the
negligent acts of such indemnified party. Lessee agrees to carry bodily injury
and property damage liability insurance during the term of the Master Lease in
amounts and against risks customarily insured against by the Lessee on equipment
owned by it. Any amounts received by Lessor under that insurance will be
credited against Lessee's obligations under this Section.

12. RISK OF LOSS.

Effective upon delivery and until the Equipment is returned, Lessee relieves
Lessor of responsibility for all risks of physical damage to or loss or
destruction of the Equipment. Lessee will carry casualty insurance for each item
of Equipment in an amount not less than the Casualty Value. All policies for
such insurance will name the Lessor and any Secured Party as additional insured
and as loss payee, and will provide for at least thirty (30) days prior written
notice to the Lessor of cancellation or expiration, and will insure Lessor's
interests regardless of any breach or violation by Lessee of any representation,
warranty or condition contained in such policies and will be primary without
right of contribution from any insurance effected by Lessor. Upon the execution
of any Schedule, the Lessee will furnish appropriate evidence of such insurance
acceptable to Lessor.

Lessee will promptly repair any damaged item of Equipment unless such Equipment
has suffered a Casualty Loss. Within fifteen (15) days of a Casualty Loss,
Lessee will provide written notice of that loss to Lessor and Lessee will, at
Lessee's option, either (a) replace the item of Equipment with Like Equipment
and marketable title to the Like Equipment will automatically vest in Lessor or
(b) pay the Casualty Value and after that payment and the payment of all other
amounts due and owing with respect to that item of Equipment, Lessee's
obligation to pay further Rent for the item of Equipment will cease.

13. DEFAULT, REMEDIES AND MITIGATION.

13.1 DEFAULT. The occurrence of any one or more of the following Events of
Default constitutes a default under a Summary Equipment Schedule:

(a)      Lessee's failure to pay Rent or other amounts payable by Lessee when
due if that failure continues for five (5) business days after written notice;
or

(b)      Lessee's failure to perform any other term or condition of the Schedule
or the material inaccuracy of any representation or warranty made by the Lessee
in the Schedule or in any document or certificate furnished to the Lessor
hereunder if that failure or inaccuracy continues for ten (10) business days
after written notice; or

(c)      An assignment by Lessee for the benefit of its creditors, the failure
by Lessee to pay its debts when due, the insolvency of Lessee, the filing by
Lessee or the filing against Lessee of any petition under any bankruptcy or
insolvency law or for the appointment of a trustee or other officer with similar
powers, the adjudication of Lessee as insolvent, the liquidation of Lessee, or
the taking of any action for the purpose of the foregoing; or

(d)      The occurrence of an Event of Default under any Schedule, Summary
Equipment Schedule or other agreement between Lessee and Lessor or its Assignee
or Secured Party.

13.2 REMEDIES. Upon the occurrence of any of the above Events of Default,
Lessor, at Its option, may:

(a)      enforce Lessee's performance of the provisions of the applicable
Schedule by appropriate court action in law or in equity;

(b)      recover from Lessee any damages and or expenses, including Default
Costs;

(c)      with notice and demand, recover all sums due and accelerate and recover
the present value of the remaining payment stream of all Rent due under the
defaulted Schedule (discounted at the same rate of interest at which such
defaulted Schedule was discounted with a Secured Party plus any prepayment fees
charged to Lessor by the Secured Party or, if there is no Secured Party, then
discounted at 6%) together with all Rent and other amounts currently due as
liquidated damages and not as a penalty;

(d)      with notice and process of law and in compliance with Lessee's security
requirements, Lessor may enter on Lessee's premises to remove end repossess the
Equipment without being liable to Lessee for damages due to the repossession,
except those resulting from Lessor's, it's assignees', agents' or
representatives' negligence; and

(e)      pursue any other remedy permitted by law or equity.

The above remedies, in Lessors discretion and to the extent permitted by law,
are cumulative and may be exercised successively or concurrently.

13.3 MITIGATION. Upon return of the Equipment pursuant to the terms of Section
13.2, Lessor will use its best efforts in accordance with its normal business
procedures (and without obligation to give any priority to such Equipment) to
mitigate Lessors damages as described below. EXCEPT AS SET FORTH IN THIS
SECTION, LESSEE HEREBY WAIVES ANY RIGHTS NOW OR HEREAFTER CONFERRED BY STATUTE
OR OTHERWISE WHICH MAY REQUIRE LESSOR TO MITIGATE ITS DAMAGES OR MODIFY ANY OF
LESSOR'S RIGHTS OR REMEDIES STATED HEREIN. Lessor may sell, lease or otherwise
dispose of all or any part of the Equipment at a public or private sale for cash
or credit with the privilege of purchasing the Equipment. The proceeds from any
sale, lease or other disposition of the Equipment are defined as either:

(a)      if sold or otherwise disposed of, the cash proceeds less the Fair
Market Value of the Equipment at the expiration of the Initial Term less the
Default Costs; or

(b)      if leased, the present value (discounted at 3 percent (3%) over the
U.S. Treasury Notes of comparable maturity to the term of the re-lease) of the
rentals for a term not to exceed the Initial Term, less the Default Costs.

Any proceeds will be applied against liquidated damages end any other sums due
to Lessor from Lessee. However, Lessee is liable to Lessor for, and Lessor may
recover, the amount by which the proceeds are less than the liquidated damages
and other sums due to Lessor from Lessee.

14. ADDITIONAL PROVISIONS.

14.1 BOARD ATTENDANCE. One representative of Lessor will have the right to
attend Lessee's corporate Board of Directors meetings and Lessee will give
Lessor reasonable notice in advance of any special Board of Directors meeting,
which notice will provide an agenda of the subject matter to be discussed at
such board meeting. Lessee will provide Lessor with a certified copy of the
minutes of each Board of Directors meeting within thirty (30) days following the
date of such meeting held during the term of this Master Lease.

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14.2 FINANCIAL STATEMENTS. As soon as practicable at the end of each month (and
in any event within thirty (30) days). Lessee will provide to Lessor the same
information which Lessee provides to its Board of Directors, but which will
include not less than a monthly income statement, balance sheet and statement of
cash flows prepared in accordance with generally accepted accounting principles,
consistently applied (the "Financial Statements"). As soon as practicable at the
end of each fiscal year, Lessee shall provide to Lessor audited Financial
Statements setting forth in comparative form the corresponding figures for the
fiscal year (and in any event within ninety (90) days), and accompanied by an
audit report and opinion of the independent certified public accountants
selected by Lessee, Lessee will promptly furnish to Lessor any additional
information (including, but not limited to, tax returns, income statements,
balance sheets and names of principal creditors) as Lessor reasonably believes
necessary to evaluate Lessee's continuing ability to meet financial obligations.
After the effective date of the initial registration statement covering a public
offering of Lessee's securities, the term "Financial Statements" will be deemed
to refer to only those statements required by the Securities and Exchange
Commission.

14.3 OBLIGATION TO LEASE ADDITIONAL EQUIPMENT. Upon notice to Lessee, Lessor
will not be obligated to lease any Equipment which would have a Commencement
Date after said notice if: (i) Lessee is in default under this Master Lease or
any Schedule; (ii) Lessee is in default under any loan agreement, the result of
which would allow the lender or any secured party to demand immediate payment of
any material indebtedness; (iii) there is a material adverse change in Lessee's
credit standing; or (iv) Lessor determines (in reasonable good faith) that
Lessee will be unable to perform its obligations under this Master Lease or any
Schedule.

14.4 MERGER AND SALE PROVISIONS. Lessee will notify Lessor of any proposed
Merger at least sixty (60) days prior to the closing date. Lessor may, in its
discretion, either (i) consent to the assignment of the Master Lease and all
relevant Schedules to the successor entity, or (ii) terminate the Lease and all
relevant Schedules. If Lessor elects to consent to the assignment, Lessee and
its successor will sign the assignment documentation provided by Lessor. If
Lessor elects to terminate the Master Lease and all relevant Schedules, then
Lessee will pay Lessor all amounts then due and owing and a termination fee
equal to the present value (discounted at 6%) of the remaining Rent for the
balance of the Initial Term(s) of all Schedules, and will return the Equipment
in accordance with Section 9. Lessor hereby consents to any Merger in which the
acquiring entity has a Moody's Bond Rating of BA3 or better or a commercially
acceptable equivalent measure of creditworthiness as reasonably determined by
Lessor.

14.5 ENTIRE AGREEMENT. This Master Lease and associated Schedules and Summary
Equipment Schedules supersede all other oral or written agreements or
understandings between the parties concerning the Equipment including, for
example, purchase orders. ANY AMENDMENT OF THIS MASTER LEASE OR A SCHEDULE, MAY
ONLY BE ACCOMPLISHED BY A WRITING SIGNED BY THE PARTY AGAINST WHOM THE AMENDMENT
IS SOUGHT TO BE ENFORCED.

14.6 NO WAIVER. No action taken by Lessor or Lessee will be deemed to constitute
a waiver of compliance with any representation, warranty or covenant contained
in this Master Lease or a Schedule. The waiver by Lessor or Lessee of a breach
of any provision of this Master Lease or a Schedule will not operate or be
construed as a waiver of any subsequent breach.

14.7 BINDING NATURE. Each Schedule is binding upon, and inures to the benefit of
Lessor end its assigns. LESSEE MAY NOT ASSIGN ITS RIGHTS OR OBLIGATIONS.

14.8 SURVIVAL OF OBLIGATIONS. All agreements, obligations including, but not
limited to those arising under Section 6.2, representations and warranties
contained in this Master Lease, any Schedule, Summary Equipment Schedule or In
any document delivered in connection with those agreements are for the benefit
of Lessor and any Assignee or Secured Party and survive the execution, delivery,
expiration or termination of this Master Lease.

14.9 NOTICES. Any notice, request or other communication to either party by the
other will be given in writing and deemed received upon the earlier of (1)
actual receipt or (2) three days after mailing if mailed postage prepaid by
regular or airmail to Lessor (to the attention of "the Comdisco Venture Group")
or Lessee, at the address set out in the Schedule, (3) one day after it is sent
by courier or (4) on the same day as sent via facsimile transmission, provided
that the original is sent by personal delivery or mail by the sending party.

14.10 APPLICABLE LAW. THIS MASTER LEASE HAS BEEN, AND EACH SCHEDULE WILL HAVE
BEEN MADE, EXECUTED AND DELIVERED IN THE STATE OF ILLINOIS AND WILL BE GOVERNED
AND CONSTRUED FOR ALL PURPOSES IN ACCORDANCE WITH THE LAWS OF THE STATE OF
ILLINOIS WITHOUT GIVING EFFECT TO CONFLICT OF LAW PROVISIONS. NO RIGHTS OR
REMEDIES REFERRED TO IN ARTICLE 2A OF THE UNIFORM COMMERCIAL CODE WILL BE
CONFERRED ON LESSEE UNLESS EXPRESSLY GRANTED IN THIS MASTER LEASE OR A SCHEDULE.

14.11 SEVERABILITY. If any one or more of the provisions of this Master Lease or
any Schedule is for any reason held invalid, illegal or unenforceable, the
remaining provisions of this Master Lease and any such Schedule will be
unimpaired, and the invalid, illegal or unenforceable provision replaced by a
mutually acceptable valid, legal and enforceable provision that is closest to
the original intention of the parties.

14.12 COUNTERPARTS. This Master Lease and any Schedule may be executed in any
number of counterparts, each of which will be deemed an original, but all such
counterparts together constitute one and the same instrument. If Lessor grants a
security interest in all or any part of a Schedule, the Equipment or sums
payable thereunder, only that counterpart Schedule marked "Secured Party's
Original" can transfer Lessor's rights and all other counterparts will be marked
"Duplicate."

14.13 LICENSED PRODUCTS. Lessee will obtain no title to Licensed Products which
will at all times remain the property of the owner of the Licensed Products. A
license from the owner may be required and it is Lessee's responsibility to
obtain any required license before the use of the Licensed Products. Lessee
agrees to treat the Licensed Products as confidential information of the owner,
to observe all copyright restrictions, and not to reproduce or sell the Licensed
Products.

14.14 SECRETARY'S CERTIFICATE. Lessee will, upon execution of this Master Lease,
provide Lessor with a secretary's certificate of incumbency and authority. Upon
the execution of each Schedule with a purchase price in excess of $1,000,000,
Lessee will provide Lessor with an opinion from Lessee's counsel in a form
acceptable to Lessor regarding the representations and warranties in Section 8.

14.15 ELECTRONIC COMMUNICATIONS. Each of the parties may communicate with the
other by electronic means under mutually agreeable terms.

14.16 LANDLORD/MORTGAGEE WAIVER. Lessee agrees to provide Lessor with a
Landlord/Mortgagee Waiver with respect to the Equipment. Such waiver shall be in
a form satisfactory to Lessor.

14.17 EQUIPMENT PROCUREMENT CHARGES/PROGRESS PAYMENTS. Lessee hereby agrees that
Lessor shall not, by virtue of its entering into this Master Lease, be required
to remit any payments to any manufacturer or other third party until Lessee
accepts the Equipment subject to this Master Lease.

14.18 DEFINITIONS.

Advance - means the amount due to Lessor by Lessee upon Lessee's execution of
each Schedule.

Assignee - means an entity to whom Lessor has sold or assigned its rights as
owner and Lessor of Equipment.

Casualty Loss - means the irreparable loss or destruction of Equipment.

Casualty Value - means the greater of the aggregate Rent remaining to be paid
for the balance of the lease term or the Fair Market Value of the Equipment
immediately prior to the Casualty Loss. However, if a Casualty Value Table is
attached to the relevant Schedule its terms will control.

Commencement Date - is defined in each Schedule.

Default Costs - means reasonable attorney's fees and remarketing costs resulting
from a Lessee default or Lessor's enforcement of its remedies.

Delivery Date - means date of delivery of Inventory Equipment to Lessee's
address.

Equipment - means the property described on a Summary Equipment Schedule and any
replacement for that property required or permitted by this Master Lease or a
Schedule.

Event of Default - means the events described in Subsection 13.1.

Fair Market Value - means the aggregate amount which would be obtainable in an
arm's-length transaction between an informed and willing buyer/user and an
informed and willing seller under no compulsion to sell.

Initial Term - means the period of time beginning on the first day of the first
full Rent Interval following the Commencement Date for all items of Equipment
and continuing for the number of Rent Intervals Indicated on a Schedule.

Interim Rent - means the pro-rata portion of Rent due for the period from the
Commencement Date through but not Including the first day of the first full Rent
interval included in the Initial Term.

Late Charge - means the lesser of five percent (5%) of the payment due or the
maximum amount permitted by the law of the state where the Equipment is located.

Licensed Products - means any software or other licensed products attached to
the Equipment.

Like Equipment - means replacement Equipment which is lien free and of the same
model, type, configuration and manufacture as Equipment.

Merger - means any consolidation or merger of the Lessee with or into any other
corporation or entity, any sale or conveyance of all or substantially all of the
assets or stock of the Lessee by or to any other person or entity in which
Lessee is not the surviving entity.

Notice Period - means not less than ninety (90) days nor more than twelve (12)
months prior to the expiration of the lease term.


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<PAGE>   4

Owner - means the owner of Equipment

Rent - means the rent Lessee will pay for each item of Equipment expressed in a
Summary Equipment Schedule either as a specific amount or an amount equal to the
amount which Lessor pays for an item of Equipment multiplied by a lease rate
factor plus all other amounts due to Lessor under this Master Lease or a
Schedule.

Rent Interval - means a full calendar month or quarter as indicated on a
Schedule.

Schedule - means either an Equipment Schedule or a Licensed Products Schedule
which incorporates all of the terms and conditions of this Master Lease.

Secured Party - means an entity to whom Lessor has granted a security interest
for the purpose of securing a loan.

Summary Equipment Schedule - means a certificate provided by Lessor summarizing
all of the Equipment for which Lessor has received Lessee approved vendor
invoices, purchase documents and/or evidence of delivery during a calendar
quarter which will incorporate all of the terms and conditions of the related
Schedule and this Master Lease and will constitute a separate lease for the
equipment leased thereunder.

IN WITNESS WHEREOF, the parties hereto have executed this Master Lease on or as
of the day and year first above written.


PLANETRX, INC.                               COMDISCO, INC.
as Lessee                                    as Lessor


By: /s/ William J. Razzouk                  By:  /s/ James P. Labe
  ----------------------------------            -------------------------------

Title: Chairman & CCO                        Title:   JAMES P. LABE
      ------------------------------               ----------------------------
                                                           PRESIDENT
                                                   COMDISCO VENTURES DIVISION


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                             EQUIPMENT SCHEDULE VL-1
                          DATED AS OF JANUARY 15, 1999
                            TO MASTER LEASE AGREEMENT
                DATED AS OF JANUARY 15, 1999 (THE "MASTER LEASE")

LESSEE:  PLANETRX, INC.                              LESSOR: COMDISCO, INC.
ADMIN. CONTACT/PHONE NO.:
---------------------------------------
                                                     ADDRESS FOR ALL NOTICES:
                                                     -------------------------
---------------------------------------              6111 North River Road
Phone: (888) 840-7979 or (650) 616-1500              Rosemont, Illinois 60018
Fax: (650) 616-1585                                  Attn.: Venture Group

Address for Notices:
---------------------------------------
340 Oyster Point Drive, Suite 201
South San Francisco, CA 94080

Central Billing Location:                            Rent Interval: Monthly
----------------------------------------             -------------
same as above

Attn.:
Lessee Reference No.:
                     ------------------
         (24 digits maximum)

Location of Equipment:                               Initial Term:   42 months
---------------------                                ------------
same as above                                        (Number of Rent Intervals)

Attn.:                                               Lease Rate Factor:
                                                     -----------------
                                                        Months 1-6:      1.00%
                                                        Months 7-12:     2.50%
                                                        Months 13-42:    3.19%

EQUIPMENT (as defined below):                        Advance:       $44,660.00
                                                     -------


Equipment specifically approved by Lessor, which shall be delivered to and
accepted by Lessee during the period January 15, 1999 through January 15, 2000
("Equipment Delivery Period"), for which Lessor receives vendor invoices
approved for payment, up to an aggregate purchase price of $1,400,000.00
("Commitment Amount"); excluding custom use equipment, leasehold improvements,
installation costs and delivery costs, rolling stock, special tooling,
"stand-alone" software, application software bundled into computer hardware,
hand held items, molds and fungible items.


<PAGE>   6

1.       EQUIPMENT PURCHASE

         This Schedule contemplates Lessor's acquisition of Equipment for lease
to Lessee, either by one of the first three categories listed below or by
providing Lessee with Equipment from the fourth category, in an aggregate value
up to the Commitment Amount referred to on the face of this Schedule. If the
Equipment acquired is of category (i), (ii), (iii) below, the effectiveness of
this Schedule as it relates to those items of Equipment is contingent upon
Lessee's acknowledgment at the time Lessor acquires the Equipment that Lessee
has either received or approved the relevant purchase documentation between
vendor and Lessor for that Equipment.

         (i)      NEW ON-ORDER EQUIPMENT. Lessor will purchase new Equipment
                  which is obtained from a vendor by Lessee for its use subject
                  to Lessor's prior approval of the Equipment.

         (ii)     SALE-LEASEBACK EQUIPMENT. Any in-place Equipment installed at
                  Lessee's site and to which Lessee has clear title and
                  ownership may be considered by Lessor for inclusion under this
                  Lease (the "Sale-Leaseback Transaction"). Any request for a
                  Sale-Leaseback Transaction must be submitted to Lessor in
                  writing (along with accompanying evidence of Lessee's
                  Equipment ownership satisfactory to Lessor for all Equipment
                  submitted) no later than March 15, 1999*. Lessor will not
                  perform a Sale-Leaseback Transaction for any request or
                  accompanying Equipment ownership documents which arrive after
                  the date marked above by an asterisk (*). Further, any
                  sale-leaseback Equipment will be placed on lease subject to:
                  (1) Lessor prior approval of the Equipment; and (2) if
                  approved, at Lessor's actual net appraised Equipment value
                  pursuant to the schedule below:

<TABLE>
<CAPTION>
                  ORIGINAL EQUIPMENT INVOICE              PERCENT OF ORIGINAL MANUFACTURER'S
                            DATE                          NET EQUIPMENT COST PAID BY LESSOR
                  --------------------------              ----------------------------------
                  <S>                                     <C>
                  Between 10/17/98 and 1/15/99                           100%
</TABLE>

Lessee represents that it has paid all California sales tax due on the cost of
that portion of Equipment to be installed in California and agrees to provide
evidence of such payment to Lessor, if specifically requested. As a result of
the election, Lessor agrees that it will not invoice Lessee for use tax on the
monthly rental rate. Lessee understands that this is an irrevocable election to
measure the tax by the Equipment and cannot be changed except prior to
installation of the Equipment.

         (iii)    USED ON-ORDER EQUIPMENT. Lessor will purchase used Equipment
                  which is obtained from a third party by Lessee for its use
                  subject to Lessor's prior approval of the Equipment and at
                  Lessor's appraised value for such used Equipment.

         (iv)     800 NUMBER EQUIPMENT. Upon Lessee's use of Comdisco's 1-800
                  Direct Service, Lessor will purchase new or used Equipment
                  from a third party or Lessor will supply new or used Equipment
                  from its inventory for use by Lessee at rates provided by
                  Lessor.

2.       COMMENCEMENT DATE

         The Commencement Date for each item of new on-order or used on-order
Equipment will be the install date as confirmed in writing by Lessee as set
forth on the vendor invoice of which a facsimile transmission will constitute an
original document. The Commencement Date for sale-leaseback Equipment shall be
the date Lessor tenders the purchase price. The Commencement Date for 800 Number
Equipment shall be fifteen (15) days from the ship date, such ship date to be
set forth on the vendor invoice or if unavailable on the vendor invoice the ship
date will be determined by Lessor upon other supporting shipping documentation.
Lessor will summarize all approved invoices, purchase documentation and evidence
of delivery, as applicable, received in the same calendar month into a Summary
Equipment Schedule in the form attached to this Schedule as Exhibit 1, and the
Initial Term will begin the first day of the calendar month thereafter. Each
Summary Equipment Schedule will contain the Equipment location, description,
serial number(s) and cost and will incorporate the terms and conditions of the
Master Lease and this Schedule and will constitute a separate lease.


<PAGE>   7

3.       OPTION TO EXTEND

         So long as no Event of Default has occurred and is continuing
hereunder, and upon written notice no earlier than twelve (12) months and no
later than ninety (90) days prior to the expiration of the Initial Term of a
Summary Equipment Schedule, Lessee will have the right to extend the Initial
Term of such Summary Equipment Schedule for a period of one (1) year. In such
event, the rent to be paid during said extended period shall be mutually agreed
upon and if the parties cannot mutually agree within ninety (90) days of the
expiration of the Initial Term, then Lessee may revoke its election to extend
the Initial Term by notice given to Lessor within five Days thereafter. If such
notice is not given and an impasse is reached, then the Summary Equipment
Schedule shall continue in full force and effect pursuant to the existing terms
and conditions until terminated in accordance with its terms. The Summary
Equipment Schedule will continue in effect following said extended period until
terminated by either party upon not less than ninety (90) days prior written
notice, which notice shall be effective as of the date of receipt.

4.       PURCHASE OPTION

         So long as no Event of Default has occurred and is continuing
hereunder, and upon written notice no earlier than twelve (12) months and no
later than ninety (90) days prior to the expiration of the Initial Term or the
extended term of the applicable Summary Equipment Schedule, Lessee will have the
option at the expiration of the Initial Term or the extended term, as
applicable, of the Summary Equipment Schedule to purchase all, but not less than
all, of the Equipment listed therein for a purchase price not to exceed fifteen
percent (15%) of the Equipment cost and upon terms and conditions to be mutually
agreed upon by the parties following Lessee's written notice, plus any taxes
applicable at time of purchase. Said purchase price shall be paid to Lessor on
the expiration date of the Initial Term or extended term. Title to the Equipment
shall automatically pass to Lessee upon payment in full of the purchase price
but, in no event, earlier than the expiration of the fixed Initial Term or
extended term, if applicable. If the parties are unable to agree on the purchase
price or the terms and conditions with respect to said purchase within ninety
(90) days of the expiration of the Initial Term or the renewal term, as
applicable, then Lessee may revoke its election to purchase the Equipment by
notice given to Lessor within five (5) days thereafter. If such notice is not
given and an impasse is reached, the Summary Equipment Schedule shall continue
in full force and effect pursuant to the existing terms and conditions until
terminated by either party upon not less than ninety (90) days prior written
notice, which notice shall be effective as of the date of receipt.
Notwithstanding the exercise by Lessee of this option and payment of the
purchase price, until all obligations under the applicable Summary Equipment
Schedule have been fulfilled, it is agreed and understood that Lessor shall
retain a purchase money security interest in the Equipment listed therein and
the Summary Equipment Schedule shall constitute a Security Agreement under the
Uniform Commercial Code of the state in which the Equipment is located.

5.       SPECIAL TERMS

         The terms and conditions of the Lease as they pertain to this Schedule
are hereby modified and amended as follows:

(a)      Section 9. "DELIVERY AND RETURN OF EQUIPMENT"

         At the end of the second sentence, insert the phrase "provided,
         however, that Lessee's expense shall be limited to the cost of
         returning Equipment shall be limited to the cost of returning the
         Equipment to Lessor's warehouse in the San Francisco Bay Area".

(b)      Section 14.18 "DEFINITIONS"

         Definition of Fair Market Value: Insert the phrase "who does not
         presently hold the Equipment" after the word "buyer/user".

<PAGE>   8

Master Lease: This Schedule is issued pursuant to the Lease identified on page 1
of this Schedule. All of the terms and conditions of the Lease are incorporated
in and made a part of this Schedule as if they were expressly set forth in this
Schedule. The parties hereby reaffirm all of the terms and conditions of the
Lease (including, without limitation, the representations and warranties set
forth in Section 8) except as modified herein by this Schedule. This Schedule
may not be amended or rescinded except by a writing signed by both parties.

PLANETRX, INC.                         COMDISCO, INC.
AS LESSEE                              AS LESSOR

By: /s/ William J. Razzouk             By:   /s/ James P. Labe
   ------------------------------           ----------------------------------
Title: Chairman and CEO                Title: JAMES P. LABE
      ---------------------------           ----------------------------------
Date:    1-18-99                                    PRESIDENT,
     ----------------------------            COMDISCO VENTURES DIVISION

                                       Date: JAN 20 1999


<PAGE>   9

                                                                       EXHIBIT 1


                           SUMMARY EQUIPMENT SCHEDULE

         This Summary Equipment Schedule dated XXXX is executed pursuant to
Equipment Schedule No. X to the Master Lease Agreement dated XXXX between
Comdisco, Inc. ("Lessor") and XXXX ("Lessee"). All of the terms, conditions,
representations and warranties of the Master Lease Agreement and Equipment
Schedule No. X are incorporated herein and made a part hereof, and this Summary
Equipment Schedule constitutes a Schedule for the Equipment on the attached
invoices.

1.       For Period Beginning:                       And Ending:

2.       Initial Term Starts on:                     Initial Term:
                                                     (Number of Rent Intervals)

3.       Total Summary Equipment Cost:

4.       Lease Rate Factor:

5.       Rent:

6.       Acceptance Doc Type:


<PAGE>   10

                             EQUIPMENT SCHEDULE VL-2
                          DATED AS OF JANUARY 15, 1999
                            TO MASTER LEASE AGREEMENT
                DATED AS OF JANUARY 15, 1999 (THE "MASTER LEASE")

LESSEE:  PLANETRX, INC.                            LESSOR: COMDISCO, INC.

ADMIN. CONTACT/PHONE NO.:                          ADDRESS FOR ALL NOTICES:
----------------------------------------
                                                   6111 North River Road
----------------------------------------           Rosemont, Illinois 60018
Phone: (888) 840-7979 or (650) 616-1500            Attn.: Venture Group
Fax: (650) 616-1585

Address for Notices:

340 Oyster Point Drive, Suite 201
South San Francisco, CA 94080

Central Billing Location:                          Rent Interval: Monthly

same as above

Attn.:
Lessee Reference No.:
                     -------------------
         (24 digits maximum)

Location of Equipment:                             Initial Term:    42 months

same as above                                      (Number of Rent Intervals)

Attn.:                                             Lease Rate Factor:

                                                     Months 1-6:       1.00%
                                                     Months 7-12:      2.50%
                                                     Months 13-42:     3.19%

EQUIPMENT (as defined below):                      Advance:          $19,140.00


Software and tenant improvements specifically approved by Lessor, which shall be
delivered to and accepted by Lessee during the period January 15, 1999 through
January 15, 2000 ("Equipment Delivery Period") for which Lessor receives vendor
invoices approved for payment, up to an aggregate purchase price of $600,000.00
("Commitment Amount"); excluding custom use equipment, installation costs and
delivery costs, rolling stock, special tooling, hand held items, molds and
fungible items.


<PAGE>   11

1.       EQUIPMENT PURCHASE

         This Schedule contemplates Lessor's acquisition of Equipment for lease
to Lessee, either by one of the first three categories listed below or by
providing Lessee with Equipment from the fourth category, in an aggregate value
up to the Commitment Amount referred to on the face of this Schedule. If the
Equipment acquired is of category (i), (ii), (iii) below, the effectiveness of
this Schedule as it relates to those items of Equipment is contingent upon
Lessee's acknowledgment at the time Lessor acquires the Equipment that Lessee
has either received or approved the relevant purchase documentation between
vendor and Lessor for that Equipment.

         (i)      NEW ON-ORDER EQUIPMENT. Lessor will purchase new Equipment
                  which is obtained from a vendor by Lessee for its use subject
                  to Lessor's prior approval of the Equipment.

         (ii)     SALE-LEASEBACK EQUIPMENT. Any in-place Equipment installed at
                  Lessee's site and to which Lessee has clear title and
                  ownership may be considered by Lessor for inclusion under this
                  Lease (the "Sale-Leaseback Transaction"). Any request for a
                  Sale-Leaseback Transaction must be submitted to Lessor in
                  writing (along with accompanying evidence of Lessee's
                  Equipment ownership satisfactory to Lessor for all Equipment
                  submitted) no later than March 15, 1999*. Lessor will not
                  perform a Sale-Leaseback Transaction for any request or
                  accompanying Equipment ownership documents which arrive after
                  the date marked above by an asterisk (*). Further, any
                  sale-leaseback Equipment will be placed on lease subject to:
                  (1) Lessor prior approval of the Equipment; and (2) if
                  approved, at Lessor's actual net appraised Equipment value
                  pursuant to the schedule below:

<TABLE>
<CAPTION>
                  ORIGINAL EQUIPMENT INVOICE          PERCENT OF ORIGINAL MANUFACTURER'S
                             DATE                     NET EQUIPMENT COST PAID BY LESSOR
                  --------------------------          ----------------------------------
                  <S>                                 <C>
                  Between 10/17/98 and 1/15/99                        100%
</TABLE>

         (iii)    USED ON-ORDER EQUIPMENT. Lessor will purchase used Equipment
                  which is obtained from a third party by Lessee for its use
                  subject to Lessor's prior approval of the Equipment and at
                  Lessor's appraised value for such used Equipment.

         (iv)     800 NUMBER EQUIPMENT. Upon Lessee's use of Comdisco's 1-800
                  Direct Service, Lessor will purchase new or used Equipment
                  from a third party or Lessor will supply new or used Equipment
                  from its inventory for use by Lessee at rates provided by
                  Lessor.

2.       COMMENCEMENT DATE

         The Commencement Date for each item of new on-order or used on-order
Equipment will be the install date as confirmed in writing by Lessee as set
forth on the vendor invoice of which a facsimile transmission will constitute an
original document. The Commencement Date for sale-leaseback Equipment shall be
the date Lessor tenders the purchase price. The Commencement Date for 800 Number
Equipment shall be fifteen (15) days from the ship date, such ship date to be
set forth on the vendor invoice or if unavailable on the vendor invoice the ship
date will be determined by Lessor upon other supporting shipping documentation.
Lessor will summarize all approved invoices, purchase documentation and evidence
of delivery, as applicable, received in the same calendar month into a Summary
Equipment Schedule in the form attached to this Schedule as Exhibit 1, and the
Initial Term will begin the first day of the calendar month thereafter. Each
Summary Equipment Schedule will contain the Equipment location, description,
serial number(s) and cost and will incorporate the terms and conditions of the
Master Lease and this Schedule and will constitute a separate lease.

3.       MISCELLANEOUS

         In consideration of Lessor financing software and tenant improvements
hereunder, Lessee agrees in addition to its last Monthly Rent Payment to remit
to Lessor an amount equal to fifteen percent (15%) of Lessor's aggregate cost of
software and tenant improvements provided hereunder.

4.       SPECIAL TERMS

         The terms and conditions of the Lease as they pertain to this Schedule
are hereby modified and amended as follows:

         (a)      Section 9. Delivery and Return of Equipment

         Delete second, third and fourth sentences in their entirety.


<PAGE>   12

Master Lease: This Schedule is issued pursuant to the Lease identified on page 1
of this Schedule. All of the terms and conditions of the Lease are incorporated
in and made a part of this Schedule as if they were expressly set forth in this
Schedule. The parties hereby reaffirm all of the terms and conditions of the
Lease (including, without limitation, the representations and warranties set
forth in Section 8) except as modified herein by this Schedule. This Schedule
may not be amended or rescinded except by a writing signed by both parties.

PLANETRX, INC.                             COMDISCO, INC.
AS LESSEE                                  AS LESSOR

By:      /s/ William J. Razzouk             By:    /s/ James P. Labe
         ------------------------------        --------------------------------
                                                       James P. Labe

Title:   CHAIRMAN & CEO                     Title: PRESIDENT
         ------------------------------            COMDISCO VENTURES DIVISION
                                                   ----------------------------
Date:    1-18-99                            Date:  JAN 20 1999
         ------------------------------            ----------------------------


<PAGE>   13


                                                                       EXHIBIT 1

                           SUMMARY EQUIPMENT SCHEDULE

         This Summary Equipment Schedule dated XXXX is executed pursuant to
Equipment Schedule No. X to the Master Lease Agreement dated XXXX between
Comdisco, Inc. ("Lessor") and XXXX ("Lessee"). All of the terms, conditions,
representations and warranties of the Master Lease Agreement and Equipment
Schedule No. X are incorporated herein and made a part hereof, and this Summary
Equipment Schedule constitutes a Schedule for the Equipment on the attached
invoices.

1. For Period Beginning:                           And Ending:

2. Initial Term Starts on:                         Initial Term:
                                                   (Number of Rent Intervals)

3. Total Summary Equipment Cost:

4. Lease Rate Factor:

5. Rent:

6. Acceptance Doc Type:


<PAGE>   14


                                 ADDENDUM TO THE
               MASTER LEASE AGREEMENT DATED AS OF JANUARY 15, 1999
                        BETWEEN PLANETRX, INC., AS LESSEE
                          AND COMDISCO, INC., AS LESSOR

         The undersigned hereby agree that the terms and conditions of the
above-referenced Master Lease are hereby modified and amended as follows:

1)       Section 3. "RENT AND PAYMENT"

         Insert the following at the end of the second sentence after the word
         "amount": "provided, however, that so long as payment is made within
         five (5) days after the date such payment is due, no late charge will
         be assessed for up to two (2) late payments under a particular Summary
         Equipment Schedule."

         Delete the last sentence in the section.

2)       Section 4.2. "WARRANT AND DISCLAIMER OF WARRANTIES"

         In line 2, delete "Lessee is not in default" and replace with "no Event
         of Default exists".

3)       Section 5.2. "RELOCATION OR SUBLEASE"

         Second paragraph, first sentence lines 1 and 2, delete the words "and
         the Secured Party."

4)       Section 5.3. "ASSIGNMENT BY LESSOR"

         Paragraph (a), second sentence lines 3 and 4, delete "Lessee is not in
         default and the Secured Party continues to receive all Rent payable
         under the Schedule" and insert "no Event of Default has occurred and is
         continuing".

5)       Section 6.2. "TAXES AND FEES"

         Second sentence, lines 2 and 3, delete "only Federal, state, local and
         franchise taxes on the capital or the net income of Lessor" and insert
         the following:

         "Excluded Taxes. Excluded Taxes means (a) taxes based upon, measured by
         or with respect to the net or gross income, items of tax preference or
         minimum tax or excess profits, receipts, capital, franchise, net worth
         or similarly-based taxes, (b) taxes on items of tax preference or any
         minimum tax or alternative minimum tax, (c) taxes imposed with respect
         to any period after either (i) Lessee's payment of the Casualty Value
         hereunder, provided, however such



<PAGE>   15

         amounts shall be limited to taxes for those items for which a Casualty
         Value was paid and, or (ii) the expiration or earlier termination of
         the Initial Term or the extended term, as applicable, and either (A)
         the return of the Equipment pursuant to the Lease or (B) the transfer
         of Lessor's interest in the Equipment pursuant to any purchase or
         termination option, (d) taxes resulting from the misconduct, negligence
         or breach by Lessor, (e) taxes which become payable by reason of any
         transfer by Lessor of its interest in the Equipment or the Summary
         Equipment Schedule, other than in connection with its exercise of any
         remedies hereunder, (f) taxes subject to any other indemnification
         hereunder, (g) taxes imposed on a successor, assignor, or other
         transferee of Lessor to the extent that such taxes would not have been
         imposed on the original Lessor or exceed the amount of taxes that would
         have been imposed and would have been indemnifiable pursuant to this
         indemnity had there not been a succession, assignment or other transfer
         by such original Lessor, (h) taxes imposed by any jurisdiction that
         would not have been imposed on Lessor but for its activities or status
         in such jurisdiction unrelated to the transactions contemplated hereby
         and (i) any taxes included in the purchase price of the Equipment
         leased hereunder."

6)       Section 7.1. "CARE, USE AND MAINTENANCE"

         Second sentence, line 4, after the words "and will provide Lessor"
insert "upon request"; line 12, after "is available and is" insert
"reasonably".

7)       Section 8. "REPRESENTATIONS AND WARRANTIES OF LESSEE"

         In paragraph (b), at the end of the sentence insert the phrase "except
         in the case of Equipment constituting tenant improvements and
         software".

         In paragraph (e), line 3, after "in the Financial Statements" insert
         "most recently delivered hereunder".

         Paragraph (f), at the end thereof insert "such that such infringement
         could have a material adverse effect on the Lessee's business
         operations.".

         Paragraph (g), at the end thereof insert "except where failure of such
         contract, agreement or instrument to be in full force and effect will
         not have a material adverse effect on the Lessee's business
         operations.".

8)       Section 9. "DELIVERY AND RETURN"

         Insert the following between the second and third sentences, insert:
         "Lessee may remove any alteration or attachment to the Equipment not
         specifically required to be delivered to Lessor hereunder or which is
         not permanently attached to the Equipment."

<PAGE>   16

         Fourth sentence, line 2, after the words "operation in place" insert
         "during normal business hours and so long as it does not unreasonably
         interfere with Lessee's operations".

         To the end of this section add, "Notwithstanding the foregoing, in the
         event that Lessor has immediately available warehouse space in the San
         Francisco bay area, Lessee's costs of returning the Equipment shall be
         limited to the costs of returning the Equipment to Lessor's warehouse
         in the San Francisco bay area."

9)       Section 11. "INDEMNITY"

         Second sentence, line 3, after the words "negligent acts" insert "or
         willful misconduct".

         At the end of this section insert the following:

         "Lessor shall not enter into any settlement or other compromise with
         respect to any claim covered by the indemnity set forth in this section
         without Lessee's prior written consent, which shall not be unreasonably
         withheld, conditioned or delayed, and if a claim is settled or
         compromised without such consent, Lessee shall not be obligated to
         provide indemnification under this section. If Lessor or any other
         indemnified party obtains recovery of any of the amounts that Lessee
         has paid to them pursuant to the indemnity set forth in this section,
         then Lessor or such other indemnified party, as applicable, shall
         promptly pay to Lessee the amount of such recovery".

10)      Section 13.1. "DEFAULT"

         In paragraph (b), line 4, delete "ten (10) business" and replace with
         "thirty (30)".

11)      Section 13.2. "REMEDIES"

         In paragraph (d), line 5, after "negligence" insert "or willful
         misconduct".

         To the end of this section add: "Any such successive or cumulative
         exercise is not intended to provide Lessor with a greater return than
         it would have received had Lessee fully performed under the terms of
         the applicable Summary Equipment Schedule.".

12)      Section 14.1. "BOARD ATTENDANCE"

         Delete this section in its entirety.

13)      Section 14.2. "FINANCIAL STATEMENTS"

<PAGE>   17

         Second sentence, lines 1 and 2, delete "the same information which
         Lessee provides to its Board of Directors, but which will include not
         less than".

14)      Section 14.3. "OBLIGATION TO LEASE ADDITIONAL EQUIPMENT"

         In line 3, after "or any Schedule" insert "and such default has not
         been cured or waived". In line 4, after "under any loan agreement"
         insert "so long as such default exists,".

15)      Section 14.4. "MERGER AND SALE PROVISIONS"

         First sentence, lines 1 and 2, delete "at least sixty (60) days prior
         to the closing date" and insert "no later than the date notice thereof
         is provided to Lessee's shareholders".

         At the end of this section add, "Lessor's consent hereunder will not be
         unreasonably delayed".

16)      Section 14.14. "SECRETARY'S CERTIFICATE"

         Delete the last sentence of this section.

17)      Section 14.18. "DEFINITIONS"

         Definition of "Casualty Value", is revised in its entirety to read:
         "means the value specified in the Casualty Value table attached hereto
         and made a part hereof."

Except as amended hereby, all other terms and conditions of the Master Lease
Agreement remain in full force and effect.

PLANETRX, INC.                            COMDISCO, INC.
AS LESSEE                                 AS LESSOR


By:      /s/ William J. Razzouk           By: /s/ James P. Labe
         --------------------------          -----------------------------------
                                                  James P. Labe

Title:   Chairman & CEO                   Title: PRESIDENT
         --------------------------               COMDISCO VENTURES DIVISION
                                                  ------------------------------

Date:    1-18-99                          Date:   JAN 20 1999
         --------------------------               ------------------------------