<PAGE>   1

                                                                   EXHIBIT 10.99

                                DRKOOP.COM, INC.

                         2000 EQUITY PARTICIPATION PLAN

            AMENDED AND RESTATED NON-QUALIFIED STOCK OPTION AGREEMENT


Unless otherwise defined herein, the terms defined in the drkoop.com, Inc. 2000
Equity Participation Plan (the "Plan") shall have the same defined meanings in
this Amended and Restated Stock Option Agreement. This Amended and Restated
Stock Option Agreement amends and restates in its entirety the Stock Option
Agreement dated April 10, 2001 previously entered into by the parties that
contained certain clerical errors.


I.      NOTICE OF STOCK ADDITIONAL OPTION GRANT

        Edward A. Cespedes

        You ("Optionee") have been granted an additional option to purchase
Common Stock of the Company, subject to the terms and conditions of the Plan and
this Stock Option Agreement. The terms of your grant are set forth below:

<TABLE>

<S>                                                  <C>
         Date of Grant:                              April 11, 2001
         Vesting Commencement Date:                  August 22, 2000
         Exercise Price per Share:                   $0.13 per share
         Total Number of Shares Granted:             390,000
         Total Exercise Price:                       $50,700.00
         Type of Option:                             Non-Qualified Stock Option
         Term/Expiration Date:                       April 10, 2008 (Seventh anniversary of
                                                     Date of Grant) - exercise period shall
                                                     not be reduced by termination of
                                                     employment

</TABLE>

        Exercise and Vesting Schedule:

        This Option shall vest and become exercisable according to the following
schedule:

<PAGE>   2

        Subject to the following paragraphs, this Option shall vest and become
exercisable with respect to thirty-three and one-third percent (33 1/3%) of the
shares of the Company's Common Stock subject to the Option (the "Shares") on the
one-year anniversary of the Option's Vesting Commencement Date, and thereafter,
with respect to thirty-three and one-third percent (33 1/3%) of the Shares on
each successive twelve-month anniversary following the one-year anniversary of
the Option's Vesting Commencement Date (each, a "Vesting Date"), commencing with
the first such anniversary, such that this Option shall be vested and
exercisable with respect to one hundred percent (100%) of the Shares on the
third anniversary of the Option's Vesting Commencement Date; provided, however,
that Optionee has remained in Continuous Status as an Employee or Consultant as
of each Vesting Date.

        Notwithstanding the foregoing, this Option shall vest and become
exercisable with respect to one hundred percent (100%) of the Shares subject to
the Option immediately prior to the earlier of (i) Optionee's termination of
employment with the Company for Good Reason or by the Company for any reason
other than Cause, death or Disability (each such term as defined in that certain
Employment Agreement between the Company and Optionee, dated as of August 22,
2000, as may be amended from time to time), (ii) in addition to the conditions
upon which the Option may automatically accelerate and become exercisable in
accordance with the Plan, upon the consummation of the following: (a) any sale,
merger, consolidation, tender offer or similar acquisition of shares, or other
transaction or series of related transactions (each a "Transaction") as a result
of which at least a majority of the voting power of the Company is not held,
directly or indirectly, by the persons or entities who held the Company's
securities with voting power before such Transaction; (b) a sale or other
disposition of all or substantially all of the Company's assets, whether in one
transaction or a series of related transactions; (c) individuals who on the date
hereof constitute the Board of Directors and any new Director (other than a
Director designated by a person or entity who has entered into an agreement to
effect a transaction described in clause (a) or (b) above) whose nomination
and/or election to the Board of Directors was approved by a vote of at least a
majority of the Directors then still in office who either were Directors on the
date hereof or whose election or nomination for election was previously so
approved, cease for any reason to constitute a majority of the Board of
Directors or (d) upon consummation of the acquisition transaction by and between
drkoop.com, Inc. and Ivonyx Group Services, Inc.

        Termination Period:

        This Option may be exercised, to the extent vested, at any time prior to
the Term/Expiration Date provided above.

II.     AGREEMENT

1. Grant of Option. The Company hereby grants to the Optionee an Option to
purchase the number of Shares set forth in the Notice of Stock Option Grant (the
"Notice of Grant"), at the exercise price per share set forth in the Notice of
Grant (the "Exercise Price"). Notwithstanding anything to the contrary anywhere
else in this Stock Option Agreement, this grant of an Option is subject to the
terms, definitions and provisions of the Plan adopted by the Company, which is
incorporated herein by reference. This Option is not intended to, and does not,
qualify as an Incentive Stock Option as defined in Section 422 of the Code.

                                       2
<PAGE>   3


      2. Exercise of Option. This Option is exercisable as follows:

         (a) Right to Exercise.

            (i) This Option shall be exercisable cumulatively according to the
vesting schedule set out in the Notice of Grant. For purposes of this Stock
Option Agreement, Shares subject to this Option shall vest based on Optionee's
Continuous Status as an Employee or Consultant.

            (ii) This Option may not be exercised for a fraction of a Share.

            (iii) In the event of Optionee's termination of Continuous Status as
an Employee or Consultant, the exercisability of the Option is governed by
Section 5 below.

            (iv) In no event may this Option be exercised after the date of
expiration of the term of this Option as set forth in the Notice of Grant.

      (b) Method of Exercise. This Option shall be exercisable by written Notice
(in the form attached as Exhibit A). The Notice must state the number of Shares
for which the Option is being exercised, and such other representations and
agreements with respect to such shares of Common Stock as may be required by the
Company pursuant to the provisions of the Plan or as may be necessary in order
for the Company to comply with Applicable Laws. The Notice must be signed by the
Optionee and shall be delivered in person or by certified mail to the Secretary
of the Company. The Notice must be accompanied by payment of the Exercise Price,
including payment of any applicable withholding tax. This Option shall be deemed
to be exercised upon receipt by the Company of such written Notice accompanied
by the Exercise Price and payment of any applicable withholding tax.

               No Shares shall be issued pursuant to the exercise of an Option
unless such issuance and such exercise comply with Applicable Laws and the
requirements of any stock exchange upon which the Shares may then be listed.
Assuming such compliance, for income tax purposes the Shares shall be considered
transferred to the Optionee on the date on which the Option is exercised with
respect to such Shares.

      3. Method of Payment. Payment of the Exercise Price shall be by any of the
following, or a combination thereof, at the election of the Optionee:

      (a) cash;

      (b) check;

      (c) with the consent of the Administrator, other shares of Common Stock
that (i) in the case of shares acquired upon exercise of an option granted by
the Company either have been owned by the Optionee for more than six months on
the date of surrender or were not acquired, directly or indirectly, from the
Company, and (y) have a Fair Market Value on the date of surrender equal to the
aggregate exercise price of the shares as to which said Option shall be
exercised;



                                       3
<PAGE>   4

      (d) with the consent of the Administrator in its sole and absolute
discretion, authorization from the Company to retain from the total number of
shares as to which the Option is exercised that number of shares having a Fair
Market Value on the date of exercise equal to the exercise price for the total
number of shares as to which the Option is exercised;

      (e) with the consent of the Administrator, delivery of a properly executed
exercise notice together with irrevocable instructions to a broker to deliver
promptly to the Company the amount of sale or loan proceeds required to pay the
exercise price;

      (f) with the consent of the Administrator, a combination of any of the
foregoing methods of payment;

      (g) with the consent of the Administrator, a combination of any of the
foregoing methods of payment at least equal in value to the stated capital
represented by the Shares to be issued, plus a promissory note for the balance
of the exercise price; or

      (h) with the consent of the Administrator, such other consideration and
method of payment for the issuance of Shares to the extent permitted under
Applicable Laws.

   4. Restrictions on Exercise. If the issuance of Shares upon such exercise
or if the method of payment for such shares would constitute a violation of any
applicable federal or state securities or other law or regulation, then the
Option may also not be exercised. The Company may require Optionee to make any
representation and warranty to the Company as may be required by any applicable
law or regulation before allowing the Option to be exercised.

   5. Termination of Relationship. If Optionee terminates Continuous Status
as an Employee or Consultant for any reason, Optionee may exercise this Option
during the Termination Period set out in the Notice of Grant, to the extent the
Option was vested at the date of such termination. To the extent that Optionee
was not vested in this Option at the date on which Optionee terminates
Continuous Status as an Employee or Consultant, or if Optionee does not exercise
this Option within the time specified herein, the Option shall terminate.

   6. Non-Transferability of Option. This Option may not be transferred in
any manner except by will or by the laws of descent or distribution . It may be
exercised during the lifetime of Optionee only by Optionee. The terms of this
Option shall be binding upon the executors, administrators, heirs, successors
and assigns of the Optionee.

   7. Term of Option. This Option may be exercised only within the term set
out in the Notice of Grant.

                            [SIGNATURE PAGE FOLLOWS]



                                       4
<PAGE>   5

               This Agreement may be executed in two or more counterparts, each
of which shall be deemed an original and all of which shall constitute one
document.

                                    DRKOOP.COM, INC.

                                    By:  /s/ RICHARD M. ROSENBLATT
                                       ----------------------------------

                                    Name:  Richard M. Rosenblatt
                                         --------------------------------

                                    Title: Chief Executive Officer
                                          -------------------------------


        OPTIONEE ACKNOWLEDGES AND AGREES THAT THE VESTING OF SHARES PURSUANT TO
        THE OPTION HEREOF IS EARNED ONLY BY CONTINUING CONSULTANCY OR EMPLOYMENT
        AT THE WILL OF THE COMPANY (NOT THROUGH THE ACT OF BEING HIRED, BEING
        GRANTED THIS OPTION OR ACQUIRING SHARES HEREUNDER). OPTIONEE FURTHER
        ACKNOWLEDGES AND AGREES THAT NOTHING IN THIS AGREEMENT, NOR IN THE
        COMPANY'S 2000 EQUITY PARTICIPATION PLAN WHICH IS INCORPORATED HEREIN BY
        REFERENCE, SHALL CONFER UPON OPTIONEE ANY RIGHT WITH RESPECT TO
        CONTINUATION OF EMPLOYMENT OR CONSULTANCY BY THE COMPANY, NOR SHALL IT
        INTERFERE IN ANY WAY WITH OPTIONEE'S RIGHT OR THE COMPANY'S RIGHT TO
        TERMINATE OPTIONEE'S EMPLOYMENT OR CONSULTANCY AT ANY TIME, WITH OR
        WITHOUT CAUSE.

        Optionee acknowledges receipt of a copy of the Plan and represents that
he is familiar with the terms and provisions thereof. Optionee hereby accepts
this Option subject to all of the terms and provisions hereof. Optionee has
reviewed the Plan and this Option in their entirety, has had an opportunity to
obtain the advice of counsel prior to executing this Option and fully
understands all provisions of the Option. Optionee hereby agrees to accept as
binding, conclusive and final all decisions or interpretations of the
Administrator upon any questions arising under the Plan or this Option. Optionee
further agrees to notify the Company upon any change in the residence address
indicated below.

Dated: April 11, 2001                       /s/ EDWARD A. CESPEDES
                                         --------------------------------
                                            EDWARD A. CESPEDES


                                            Residence Address:




                                       5
<PAGE>   6

                                    EXHIBIT A

                                DRKOOP.COM, INC.

                         2000 EQUITY PARTICIPATION PLAN

                                 EXERCISE NOTICE


drkoop.com, Inc.

Attention:  Secretary

      1. Exercise of Option. Effective as of today, ___________, _____, the
undersigned ("Optionee") hereby elects to exercise Optionee's option to purchase
_________ shares of the Common Stock (the "Shares") of drkoop.com, Inc. (the
"Company") under and pursuant to the drkoop.com, Inc. 2000 Equity Participation
Plan (the "Plan") and the Non-Qualified Stock Option Agreement dated
_____________, _____, (the "Option Agreement").

      2. Representations of Optionee. Optionee acknowledges that Optionee has
received, read and understood the Plan and the Option Agreement. Optionee agrees
to abide by and be bound by their terms and conditions.

      3. Rights as Stockholder. Until the stock certificate evidencing such
Shares is issued (as evidenced by the appropriate entry on the books of the
Company or of a duly authorized transfer agent of the Company), no right to vote
or receive dividends or any other rights as a stockholder shall exist with
respect to Shares subject to the Option, notwithstanding the exercise of the
Option. The Company shall issue (or cause to be issued) such stock certificate
promptly after the Option is exercised. No adjustment will be made for a
dividend or other right for which the record date is prior to the date the stock
certificate is issued, except as provided in Section IV of Article One of the
Plan. Optionee shall enjoy rights as a stockholder until such time as Optionee
disposes of the Shares.

      4. Tax Consultation. Optionee understands that Optionee may suffer adverse
tax consequences as a result of Optionee's purchase or disposition of the
Shares. Optionee represents that Optionee has consulted with any tax consultants
Optionee deems advisable in connection with the purchase or disposition of the
Shares and that Optionee is not relying on the Company for any tax advice.

      5. Restrictive Legends.

            (a) Legends. Optionee understands and agrees that the Company shall
cause any other legends that may be required by state or federal securities laws
to be placed upon any certificate(s) evidencing ownership of the Shares.

            (b) Refusal to Transfer. The Company shall not be required (i) to
transfer on its books any Shares that have been sold or otherwise transferred in
violation of any of the provisions of


<PAGE>   7

this Agreement or (ii) to treat as owner of such Shares or to accord the right
to vote or pay dividends to any purchaser or other transferee to whom such
Shares shall have been so transferred.

      6. Successors and Assigns. The Company may assign any of its rights under
this Agreement to single or multiple assignees, and this Agreement shall inure
to the benefit of the successors and assigns of the Company. Subject to the
restrictions on transfer herein set forth, this Agreement shall be binding upon
Optionee and his or her heirs, executors, administrators, successors and
assigns.

      7. Interpretation. Any dispute regarding the interpretation of this
Agreement shall be submitted by Optionee or by the Company forthwith to the
Administrator, which shall review such dispute at its next regular meeting. The
resolution of such a dispute by the Administrator shall be final and binding on
the Company and on Optionee.

      8. Governing Law; Severability. This Agreement shall be governed by and
construed in accordance with the laws of the State of Texas excluding that body
of law pertaining to conflicts of law. Should any provision of this Agreement be
determined by a court of law to be illegal or unenforceable, the other
provisions shall nevertheless remain effective and shall remain enforceable.

      9. Notices. Any notice required or permitted hereunder shall be given in
writing and shall be deemed effectively given upon personal delivery or upon
deposit in the United States mail by certified mail, with postage and fees
prepaid, addressed to the other party at its address as shown below beneath its
signature, or to such other address as such party may designate in writing from
time to time to the other party.

      10. Further Instruments. The parties agree to execute such further
instruments and to take such further action as may be reasonably necessary to
carry out the purposes and intent of this Agreement.

      11. Delivery of Payment. Optionee herewith delivers to the Company the
full Exercise Price for the Shares, as well as any applicable withholding tax.



                                       1
<PAGE>   8


      12. Entire Agreement. The Plan and Option Agreement are incorporated
herein by reference. This Agreement, the Plan and the Option Agreement
constitute the entire agreement of the parties and supersede in their entirety
all prior undertakings and agreements of the Company and Optionee with respect
to the subject matter hereof.

Submitted by:                                     Accepted by:

OPTIONEE:                                         DRKOOP.COM, INC.


                                                  By:
---------------------------------------------        --------------------------

                                                  Its:
                                                      -------------------------

Address:

-------------------------------

-------------------------------

-------------------------------





                                       2