Document:

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                                                                  Exhibit 10.158

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                   Pharmaceutical Product Development, Inc.

                          Deferred Compensation Plan

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                       Effective Date:  February 1, 2001

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                      Pharmaceutical Product Development, Inc.

                             Deferred Compensation Plan
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I.   Name and Purpose

The name of this plan is the Pharmaceutical Product Development, Inc. Deferred
Compensation Plan (the "Plan"). Its purpose is to provide certain select
management or highly compensated employees on the payroll of either
Pharmaceutical Product Development, Inc. (the "Company") or a subsidiary of the
Company (the "Affiliates") with the opportunity to defer compensation earned as
an employee.

II.  Effective Date

The Plan shall be effective as of February 1, 2001.

III. Participants

All employees who are officers, senior vice presidents, vice presidents and
executive directors of the Company or an Affiliate who are receiving
compensation in the United States from the Company or an Affiliate shall be
eligible to participate in the Plan. Any such Employee who elects to participate
in the Plan is hereinafter called a "Participant." The Company will establish
for each Participant one or more unfunded deferred compensation accounts, as
specified in Section V.

IV.  Election of Deferral

     A.  On or before December 31 of any year, each Employee eligible to
         participate shall be entitled to make an irrevocable election (in the
         form of Exhibit A) to defer receipt of all or a specified portion of
         the salary otherwise payable (whether or not otherwise deferred) from
         the Company for the following calendar year. Such election shall remain
         effective from year to year, unless changed by the Employee with
         respect to the next following calendar year.

     B.  For the first calendar year that an Employee becomes eligible, an
         Employee must make an irrevocable election (in the form of Exhibit A)
         within 30 days after the Employee becomes eligible. Elections for the
         2001 calendar year shall be made prior to January 31, 2001, in
         accordance with rules adopted by the Committee .

     C.  The term "salary" as used herein shall include all compensation other
         than income from the exercise of stock options, relocation expense
         reimbursements and tuition reimbursements. If a Participant wishes to
         defer the payment of all or a portion of the bonus earned for a
         particular year (whether or not he otherwise elects to defer salary),
         he must make a separate election. Such election will apply to the
         fiscal year of the Company in which the bonus is paid. Such election
         must be completed and returned to the Company on or before December 31
         immediately preceding the beginning of the fiscal year of the Company
         during

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         which the bonus would be paid; provided, however, for the plan
         year beginning February 1, 2001, such election shall be made by January
         31, 2001.

     D.  Employees may elect to defer receipt of between one and twenty-five
         percent of salary, other than bonus, in increments of one percent.
         Employees, other than officers, senior vice presidents and vice
         presidents, may elect to defer receipt of between one and twenty-five
         percent of bonus, in increments of one percent. Officers, senior vice
         presidents and vice presidents may elect to defer receipt of between
         one and one hundred percent of bonus in increments of one percent.

     E.  A Participant's deferrals under the Plan shall be determined before a
         Participant's contributions to the Pharmaceutical Product Development,
         Inc. Retirement Savings Plan ("RSP"). A Participant shall make separate
         deferral elections with respect to the Plan and the RSP. At anytime
         during a calendar year a Participant by timely notifying the Committee,
         in accordance with it rules and procedures, may elect to suspend
         deferrals to the Plan. Such Participant may elect deferral for
         subsequent calendar years in accordance with the procedures in this
         Article IV.

V.  Deferred Compensation Accounts

     A.  Separate Accounts (and subaccounts if elected in accordance with D.
         below) shall be established and maintained for each Participant
         reflecting the amount deferred by the Participant in the Plan.

     B.  At the end of each calendar quarter an amount equal to the
         Participant's deferral for such quarter shall be credited to the
         appropriate Account of such Participant to reflect the salary or bonus
         otherwise payable during payroll periods ending in that calendar
         quarter but deferred pursuant to the Plan by the Participant. Interest
         will be credited to the Participant's Account as of the last day of
         each calendar quarter based upon the balance in the Participant's
         Account on the first day of such quarter after reducing that Account to
         reflect any distributions or withdrawals from such Account during such
         quarter and after crediting the Account with fifty percent of the
         deferrals for such calendar quarter. Interest for each calendar quarter
         shall be based on the three month London Interbank Offered Rate (or
         similar index designated by the Committee) plus 1.5%.

     C.  Separate subaccounts shall be established for a Participant if the
         Participant so elects and the Committee so approves in accordance with
         Section VII.

VI.  Method of Distribution of Deferred Compensation

     A.  At the time a Participant executes his or her first Deferral Agreement,
         the Participant shall duly designate, execute, and file with the
         Committee on the Deferral Agreement or other appropriate form
         designated by the Committee the date upon which the entire amount of
         his or her Account shall become payable. A Participant may designate
         that payment of his or her Account commences (the "distribution event
         date") upon (a) the date of the Participant's termination of employment
         or (b) a date 10 years after termination of employment.

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     B.  At the time a Participant first elects a distribution event date under
         A, the Participant shall elect one of the following forms of payment
         for the amount of his or her Account:

         (i)  Lump Sum. The Participant shall receive a single sum cash payment
              equal to the amount credited to his or her Account. In the event a
              Participant elects a single sum payment, the amount of the
              Participant's Account shall be paid as soon as practicable
              following the calendar year during which the Participant's
              distribution event date occurs.

         (ii) Installments. The Participant shall receive the amount credited to
              his or her Account in ratable semi-annual installments payable
              over a period of 5, 10 or 15 years; provided however, that in no
              event may any semi-annual installment (except the last
              installment) be in an amount of less than $2,000 (or such other
              amount the Committee may specify); and provided further, that in
              the event the installment period elected by the Participant would
              otherwise result in one or more semi-annual installments of less
              than $2,000, then such installment period may be automatically
              shortened by the Committee to the extent necessary to assure that
              each such installment (except for the last one) will be an amount
              of not less than $2,000. Such semi-annual installments shall
              commence as soon as practicable following the January 1 or July 1
              immediately following the Participant's distribution event date
              and payable throughout the installment period to the participant
              as soon as practicable after each January and July 1 thereafter.
              In the event a Participant terminates employment before attaining
              age 55 and completing 10 years of service with the Company or an
              Affiliate, terminates employment under circumstances deemed by the
              Committee to be detrimental to the Company or works for a
              competitor of the Company then the Committee shall,
              notwithstanding any installment election made by the Participant,
              pay the amount the Participant has remaining in his Account, in a
              lump sum payment as soon as practicable.

     C.  A Participant may change his or her elections under A or B at any time
         by duly completing, executing, and filing with the Committee his or her
         new election in an appropriate form designated by the Committee;
         provided however, that for any such change of election to be effective,
         a full calendar year must pass between the calendar year during which
         the Participant duly makes the change of election and the calendar year
         during which distribution of any portion of the Participant's Account
         is first to become payable after taking the change of election into
         account. In the event a Participant has not made an election under A or
         B that is effective upon termination of employment, then the
         Participant shall be treated as having a distribution event date that
         is the date of the Participant's termination of employment under A; or
         a form of payment of a lump sum under B; as the case may be.

     D.  At any time a Participant may withdraw all or any fixed dollar portion
         of the Participant's Account by duly completing, executing, and filing
         with the Committee the appropriate form designated by the Committee
         establishing that

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         the Participant has a severe financial hardship. The Committee, in its
         sole and absolute discretion, shall determine whether the Participant
         has suffered a financial hardship justifying a withdrawal. In addition,
         at any time a Participant may withdraw all or any fixed dollar portion
         of the Participant's Account by duly completing, executing and filing
         with the Committee the appropriate form designated by the Committee for
         a significant detriment withdrawal. The Committee will process such
         significant detriment withdrawal request, but shall cause a forfeiture
         to the Company from the Participant's Account of 10% of the amount
         requested by the Participant. The Participant shall receive 90% of the
         amount requested.

     E.  Notwithstanding the foregoing provisions of this Section VI, upon a
         Change in Control, the Plan will be deemed to have been terminated and
         a Participant's Account shall be paid to the Participant in a lump sum
         as soon as practicable; provided, however, a Participant may elect by
         duly completing, executing, and filing with the Committee on an
         appropriate form designated by the Committee that the Participant
         elects to continue to participate in the Plan, and in such event, the
         Plan will not be deemed to have been terminated with respect to the
         Participant and the Participant's Account shall not be distributed.
         Such election shall be made during the period ending on the date 30
         days following the date the Board approves a corporate event leading to
         a change in control or announces it to employees generally. Upon
         payment under this Section VI E, the obligation of the Plan and the
         Company to the Participant shall be fully satisfied and completely
         discharged, and the Participant shall be permanently barred from
         further participation in the Plan. "Change in Control" means (i) a
         change of control of a nature that would be required to be reported in
         response to Item 6(e) of Schedule 14A of Regulation 4A promulgated
         under the Securities Exchange Act of 1934, as amended ("Exchange Act"),
         provided that such a Change in Control shall be deemed to have occurred
         if any "person" (as such term is used in Sections 13(d) and 14 (d)(2)
         of the Exchange Act) is or becomes the beneficial owner, directly or
         indirectly, of securities of the Company representing 50% or more of
         the combined voting power of the Company's then outstanding securities;
         (ii) a sale of substantially all of the assets of the Company; or (iii)
         a liquidation of the Company.

     F.  Any amounts debited from a Participant's Account by reason of a
         distribution, withdrawal, or otherwise under this Section VI, shall be
         debited from the Participant's Account, and such other accounts,
         subaccounts, options, or other allocations in the same proportion that
         the Participant's entire Account is credited at the time such debit is
         made, as determined by the Committee.

VII.  In-Service Subaccount

     A.  A Participant may request that the Committee establish one or more
         Subaccounts providing for an in-service withdrawal that is not
         occasioned by a severe hardship or a significant detriment withdrawal
         by duly completing, executing, and filing with the Committee such
         request on an appropriate form designated by the Committee. The
         Committee may condition its approval of any Subaccount. Each Subaccount
         the Committee approves for a Participant shall be

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         established as of the start of the calendar year following the calendar
         year during which the Committee's approval occurs; provided however,
         that in the event the Committee's approval for a Subaccount occurs
         after December 15 of a calendar year, then such Subaccount shall be
         established as of the start of the calendar year second following the
         calendar year during which such Committee approval occurred. The
         portion of an Employee's Account not credited to one or more of his or
         her Subaccounts is the Employee's Account. An Employee shall have until
         January 15, 2001, to request the establishment of a Subaccount upon the
         effective date of the Plan.

     B.  Except as provided in the following provisions of this Section VII,
         each Subaccount of a Participant shall be treated as a separate Account
         under the foregoing Sections of this Plan.

     C.  The overall limits on the maximum amounts of deferrals shall apply with
         respect to all of the Participant's Subaccounts as if all such
         Subaccounts were a single Account under the Plan. A Participant may
         designate the total amount and allocation of deferrals among his or her
         Subaccounts by completing, executing, and filing with the Committee the
         appropriate form designated by the Committee by December 15 of the
         calendar year before the calendar year in which the change is to be
         effective. In the event a Participant evidences severe financial
         hardship for a year, then all deferrals to all of the Participant's
         Subaccounts shall be stopped.

     D.  The distribution event date for each of the Participant's Subaccounts
         shall be any distribution event date irrevocably specified by the
         Employee that is no less than three years following the date the first
         amount is actually credited to that Subaccount upon duly completing,
         executing, and filing with the Committee the appropriate form
         designated by the Committee no later than the time such Subaccount is
         established. No later than the establishment of a Subaccount for a
         Participant, the Participant shall irrevocably designate on such form a
         semi-annual installment form of payment for a period that is not more
         than eight semi-annual installments. Separate elections under the
         foregoing provisions of this Section VII, D will be made for each
         Subaccount established for a Participant. No withdrawals before the
         distribution event date may be made from any Subaccount. In the event a
         Participant fails to designate either the timing or form of
         distribution of any Subaccount established for the Participant, then
         any amounts that are or would have been allocated to such Subaccount
         shall be credited instead to the Participant's Account. All of a
         Participant's Subaccounts shall be treated as a single Account under
         the Plan for purposes of any death benefits payable under the Plan.

     E.  A Participant may elect to dissolve any Subaccount established on his
         or her behalf and to transfer the balance of that Subaccount in
         multiples of 10 percent of each balance to his or her other
         Subaccounts, or 100 percent of such balance to his or her Account, as
         the case may be, by duly completing, executing, and filing with the
         Committee an appropriate form designated by the Committee; provided
         however, that for an election to dissolve a Subaccount to be effective,
         a full calendar year must pass between the calendar year during which

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         the Participant duly makes the dissolution election and the calendar
         year during which distribution of any portion of such Subaccount is
         first to become payable; and provided further that in the absence of
         such elective allocation of the balance of the Subaccount upon its
         dissolution, that the balance shall be transferred in its entirety to
         the Participant's Account. In no other event may transfers be made
         among the Participant's Subaccounts.

VIII.  Distribution Upon Death

If any Participant dies before receiving all amounts credited to his Account,
the unpaid amounts in the Participant's account shall be paid to the
Participant's beneficiary or beneficiaries in accordance with the last effective
beneficiary designation form filed by the Participant with the Committee. Such
unpaid amounts shall be paid in one lump sum within 30 days after the date of
death.  Each Participant shall file with the Committee a form indicating the
person, persons, or entity which are to receive the Participant's benefits under
the Plan if he dies before receiving all the balances in his Account. A
Participant's beneficiary designation may be changed at any time prior to his
death by execution and delivery of a new beneficiary designation form. If a
Participant has failed to designate a beneficiary or no designated beneficiary
survives the Participant, payment shall be made in a lump sum to the estate of
the Participant. A beneficiary who fails to survive a Participant by at least 10
days shall be deemed to have predeceased the Participant.

IX.    Benefit Plans

       A. The amount of each Participant's compensation which he elects to defer
          under the Plan shall not be deemed to be compensation for the purpose
          of calculating the amount of a Participant's benefits or contributions
          under a pension plan or retirement plan (qualified under Section
          401(a) of the Internal Revenue Code), but shall be deemed to be
          compensation for purpose of calculating the amount of a Participant's
          amount of life insurance under a Company-supplied life insurance plan,
          the basis for establishing disability payments under a disability plan
          or the basis or amount for any other Company-supplied benefit plan
          where the benefits are based upon an employee's compensation.

       B. With respect to any benefit plan under which an Employee's
          contribution is based on the Employee's compensation, the amount of
          the Participant's contribution to any such plan shall not take into
          account the amount of the Participant's compensation deferred under
          this Plan unless otherwise specifically provided in such plan.

       C. No amount distributed to a Participant from a Participant's Account
          under this Plan shall be deemed to be compensation with respect to a
          Participant's entitlement to benefits under any employee benefit plan
          established by the Company for its employees unless otherwise
          specifically provided in such plan.

X.     Participant's Rights

Establishment of the Plan shall not be construed to give any Participant the
right to be retained in the Company's or an Affiliate's service or to any
benefits not specifically provided by the Plan.

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A Participant shall not have any interest in the deferred compensation and
earnings credited to his Account until such accounts are distributed in
accordance with the Plan. All amounts deferred or otherwise held for the account
of a Participant under the Plan shall remain the sole property of the Company,
subject to the claims of its general creditors and available for its use for
whatever purposes are desired. With respect to amounts deferred or otherwise
held for the account of a Participant, the Participant is merely a general
creditor of the Company; and the obligation of the Company hereunder is purely
contractual and shall not be funded or secured in any way. At its discretion,
the Company may establish one or more grantor trusts to assist the Company in
accumulating the funds needed to meets its obligation under the Plan.

In case the claim of any Participant or beneficiary for benefits under the Plan
is denied, the Committee shall provide adequate notice in writing to such
claimant, setting forth the specific reasons for such denial. The notice shall
be written in a manner calculated to be understood by the claimant. The
Committee shall afford a Participant or beneficiary whose claim for benefits has
been denied 60 days from the date notice of such denial is delivered or mailed
in which to appeal the decision in writing to the Committee. If the Participant
or beneficiary appeals the decision in writing within 60 days, the Committee
shall review the written comments and any submissions of the Participant or
beneficiary and render its decision regarding the appeal all within 60 days of
such appeal.

XI.    Non-alienability and Non-transferability

The rights of a Participant to the payment of deferred compensation as provided
in the Plan shall not be assigned, transferred, pledged or encumbered, or be
subject in any manner to alienation or anticipation. No Participant may borrow
against his Account. No Account shall be subject in any manner to anticipation,
alienation, sale, transfer, assignment, pledge, encumbrance, charge,
garnishment, execution, or levy of any kind, whether voluntary or involuntary,
including any liability which is for alimony or other payments for the support
of a spouse or former spouse, or for any other relative of any Participant.

XII.   Statement of Account

Statements will be sent to Participants within 60 days after the end of each
calendar quarter as to the balance in their deferred compensation Accounts as of
the end of such calendar quarter.

XIII.  Administration

The Administrator of the Plan shall be the Benefits Administrative Committee of
the Company (the "Committee"). The Committee shall have authority to adopt rules
and regulations for carrying out the Plan and to interpret, construe, and
implement the provisions thereof. Any decision or interpretation of any
provision of the Plan adopted by the Committee shall be final and conclusive.

XIV.   Amendment and Termination

The Plan may, at any time, be amended, modified, or terminated by the Board of
Directors of the Company. No amendment, modification, or termination shall,
without the consent of a Participant, adversely affect such Participant's right
with respect to amounts accrued in his or her deferred compensation Account.

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XV.    General Provisions

       A. Notices. All notices to the Committee hereunder shall be delivered to
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          the attention of the Secretary of the Committee. Any notice or filing
          required or permitted to be given to the Committee under this Plan
          shall be sufficient if in writing and hand delivered, or sent by
          registered or certified mail, to the Committee at the principal office
          of the Company. Such notice shall be deemed given as of the date of
          delivery or, if delivery is made by mail, as of the date shown on the
          postmark or the receipt for registration or certification.

       B. Controlling Law. Except to the extent superseded by federal law, the
          ---------------
          laws of the state of North Carolina shall be controlling in all
          matters relating to the Plan.

       C. Gender and Number. Where the context admits, words in the masculine
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          gender shall include the feminine and neuter genders, the plural shall
          include the singular and the singular shall include the plural.

       D. Captions. The captions of Sections and paragraphs of this Plan are for
          --------
          convenience only and s hall not control or affect the meaning of
          construction of any of its provisions.

       E. Action by the Company. Any action required or permitted by the Company
          ---------------------
          under the Plan shall be by resolution of its Board of Directors or any
          person or persons authorized by resolution of its Board of Directors.

       F. Facility of Payment. Any amounts payable hereunder to any person under
          -------------------
          legal disability or who, in the judgment of the Committee is unable to
          properly manage his financial affairs may be paid to the legal
          representative of such person or may be applied for the benefit of
          such person in any manner which the Committee may select.

       G. Withholding Payroll Taxes. To the extent required by the laws in
          -------------------------
          effect at the time amounts are deferred or deferred compensation
          payments are made, the Company shall withhold (from other compensation
          in the case of deferrals) any taxes required to be withheld for
          federal, state, or local government purposes.

       H. Severability. Whenever possible, each provision of the Plan shall be
          ------------
          interpreted in such manner as to be effective and valid under
          applicable law (including the Internal Revenue Code), but if any
          provision of the Plan shall be held to be prohibited by or invalid
          under applicable law, then (a) such provision shall be deemed amended
          to, and to have contained from the outset such language as shall be
          necessary to, accomplish the objectives of the provision as originally
          written to the fullest extent permitted by law and (b) all other
          provisions of the Plan shall remain in full force and effect.

       I. No Strict Construction. No rule of strict construction shall be
          ----------------------
          applied against the Company, the Board of Directors, Committee or any
          other person in the interpretation of any of the terms of the Plan or
          any rule or procedure established by the Company or Committee.

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       J. Successors. The provisions of the Plan shall bind and inure to the
          ----------
          benefit of the Company and its Affiliates and their successors and
          assigns. The term "successors" as used herein shall include any
          corporation or other business entity which shall by merger,
          consolidation, purchase, or otherwise, acquire all or substantially
          all of the business and assets of the Company and successors of any
          such corporation or other business entity.

XVI.  Unfunded State of the Plan

Any and all payments made to the Participant pursuant to the Plan shall be made
only from the general assets of the Company, or at the discretion of the
Company, such payments shall be made from a grantor trust established by the
Company. All accounts under the Plan shall be for bookkeeping purposes only and
shall not represent a claim against specific assets of the Company. Nothing
contained in this Plan shall be deemed to create a trust of any kind or create
any fiduciary relationship.

IN WITNESS WHEREOF, Pharmaceutical Product Development, Inc. has caused its
corporate seal to be hereunto affixed and has caused its name to be signed
hereto by its Chief Executive Officer and attested by its Secretary, pursuant to
due authority of its Board of Directors as of this 4th day January, 2001.

                                   By: /s/ Fredric N. Eshelman
                                       ---------------------------------------
                                       Chief Executive Officer
                                       Pharmaceutical Product Development, Inc.

(Corporate Seal)

Attest:

/s/ Fred B. Davenport, Jr.
-------------------------
Secretary

                                      -10-<PAGE>

                                                                  EXHIBIT 10.159

                                FIFTH AMENDMENT

     THIS FIFTH AMENDMENT (this "Amendment") dated as of December 19, 2000, to
                                 ---------
the Loan Agreement referenced below, is by and among Pharmaceutical Product
Development, Inc., a North Carolina corporation (the "Borrower"), the
                                                      --------
Subsidiaries of the Borrower identified on the signature pages hereto (the
"Guarantors") and First Union National Bank (the "Bank").  Terms used herein but
 ----------                                       ----
not otherwise defined herein shall have the meanings provided to such terms in
the Loan Agreement.

                              W I T N E S S E T H

     WHEREAS, a $50 million credit facility has been established in favor of the
Borrower pursuant to the terms of that Loan Agreement dated as of June 24, 1998
(as amended and modified from time to time, the "Loan Agreement") among the
                                                 --------------
Borrower, the Guarantors and the Bank;

     WHEREAS, the Borrower has requested certain modifications to Loan
Agreement;

     WHEREAS, the Bank has agreed to the modifications on the terms and
conditions set forth herein;

     NOW, THEREFORE, IN CONSIDERATION of the premises and other good and
valuable consideration, the receipt and sufficiency of which are hereby
acknowledged, the parties hereto agree as follows:

     1.   Section 6.9 of the Loan Agreement is amended to read as follows:

          6.9   Investments.  The Borrower will not, nor will it permit any of
                -----------
          its subsidiaries to, make loans or advances or otherwise make an
          investment in or capital contribution to (collectively, an
          "Investment"), any other Person, except:
           ----------

               (a)  cash and cash equivalents and other publicly traded equity
          and debt instruments reasonably acceptable to the Bank;

               (b)  loans and advances to officers, directors, employees and
          shareholders not to exceed $2,000,000;

               (c)  Investments in and to Digital Arts & Science in an aggregate
          principal amount (on a cost basis) not to exceed $1,500,000 at any
          time;

               (d)  Investments in and to Axys Pharmaceuticals, Inc. and/or
          PPGx, Inc. in an aggregate principal amount (on a cost basis) not to
          exceed $3,500,000 at any time;

               (e)  seller financing promissory note from current management of
          APBI in favor of the Borrower in an aggregate principal amount not to
          exceed $18,000,000 in connection with the sale of APBI to current
          management of APBI;

               (f)  cash equity investments in and to ADoctorInYourHouse.com in
          an aggregate principal amount (on a cost basis) not to exceed
          $5,000,000 at any time;
<PAGE>

               (g)  loans and advances to NeoRx in an aggregate principal amount
          not to exceed $5,000,000 at any time;

               (h)  acquisition of capital stock of DNA Sciences, Inc. in an
          amount not to exceed $15,000,000;

               (i)  cash equity investment in PPGx, Inc. in an amount equal to
          fifty percent (50%) of the outstanding amounts (principal and
          interest) due under the Loan Agreement dated as of February 1, 1999
          among PPGx, Inc., the Borrower and the Bank;

               (j)  acquisition of capital stock of PPGx, Inc. in an amount not
          to exceed $5,900,000;

               (k)  Investments in and to a Credit Party; and

               (l)  other Investments in an aggregate principal amount (on a
          cost basis) at any time of up to $5,000,000.

     2.   This Amendment shall be effective upon execution of this Amendment by
the Borrower, the Guarantors and the Bank.

     3.   Except as modified hereby, all of the terms and provisions of the Loan
Agreement (including Schedules and Exhibits) shall remain in full force and
effect.

     4.   The Borrower agree to pay all reasonable costs and expenses of the
Bank in connection with the preparation, execution and delivery of this
Amendment, including without limitation the reasonable fees and expenses of
Moore & Van Allen, PLLC.

     5.   This Amendment may be executed in any number of counterparts, each of
which when so executed and delivered shall be deemed an original and it shall
not be necessary in making proof of this Amendment to produce or account for
more than one such counterpart.

     6.   This Amendment shall be deemed to be a contract made under, and for
all purposes shall be construed in accordance with, the laws of the State of
North Carolina.

                 [Remainder of Page Intentionally Left Blank]

                                       2
<PAGE>

     IN WITNESS WHEREOF, each of the parties hereto has caused a counterpart of
this Amendment to be duly executed and delivered as of the date first above
written.

BORROWER:                              PHARMACEUTICAL PRODUCT DEVELOPMENT, INC.,
                                       a North Carolina corporation

                                       By: /s/Fred B. Davenport, Jr.
                                          ----------------------------------
                                       Name: Fred B. Davenport, Jr.
                                       Title: Vice President

GUARANTORS:                            PPD DEVELOPMENT, LLC,
                                       a Texas limited liability company

                                       By: /s/Fred B. Davenport, Jr.
                                          ----------------------------------
                                       Name: Fred B. Davenport, Jr.
                                       Title: Manager

BANK:                                  FIRST UNION NATIONAL BANK

                                       By: /s/G. Mendel Lay, Jr.
                                          ----------------------------------
                                       Name: G. Mendel Lay, Jr.
                                       Title:  Senior Vice President

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