<PAGE>

                                                                    Exhibit 10.2
                             PRA INTERNATIONAL, INC.

                                 FIRST AMENDMENT
                    TO AMENDED AND RESTATED CREDIT AGREEMENT
                        AND CERTAIN OTHER LOAN DOCUMENTS

            This FIRST AMENDMENT TO AMENDED AND RESTATED CREDIT AGREEMENT AND
CERTAIN OTHER LOAN DOCUMENTS (this "AMENDMENT") is dated as of May 17, 2004 and
entered into by and among PRA International, Inc., a Delaware corporation
("COMPANY"), PRA Holdings, Inc., a Delaware corporation ("HOLDINGS"), PRA Sub,
Inc., a Delaware corporation ("PRA SUB"), the Subsidiary Guarantors listed on
the signature pages hereof, the financial institutions listed on the signature
pages hereof and Wells Fargo Bank, National Association, as administrative agent
for Lenders ("ADMINISTRATIVE AGENT"), and is made with reference to (i) that
certain Amended and Restated Credit Agreement dated as of December 23, 2003 (the
"CREDIT AGREEMENT"), by and among Company, the financial institutions from time
to time party thereto ("LENDERS"), Co-Lead Arranger and Syndication Agent,
Co-Documentation Agents and Administrative Agent, (ii) that certain Amended and
Restated Holdings Pledge Agreement dated as of December 23, 2003 (the "HOLDINGS
PLEDGE AGREEMENT"), executed by Holdings, PRA Sub and Administrative Agent, and
(iii) that certain Amended and Restated Security Agreement dated as of December
23, 2003 (the "SECURITY AGREEMENT"), executed by Company, Subsidiary Guarantors
and Administrative Agent. Capitalized terms used herein without definition shall
have the same meanings herein as set forth in the Credit Agreement.

                                    RECITALS

            WHEREAS, Company and Lenders desire to amend the Credit Agreement
and certain other Loan Documents (i) to allow Company to enter into certain
foreign credit facilities to be secured under the Collateral Documents, and (ii)
to make certain other amendments as set forth below; and

            WHEREAS, on the date hereof, Wells Fargo Bank, National Association
is assigning $2,500,000 of its outstanding Tranche A Term Loan to CIBC, Inc.;
Wachovia Bank, National Association is assigning $1,250,000 of its outstanding
Tranche A Term Loan and $1,250,000 of its outstanding Tranche B Term Loan to
CIBC, Inc.; CIBC, Inc. is making a Tranche A Term Loan in the amount of
$1,666,667, a Tranche B Term Loan in the amount of $3,333,333 and a Revolving
Loan Commitment in the amount of $5,000,000; and the aggregate Revolving Loan
Commitment is being reduced to $23,750,000;

            NOW, THEREFORE, in consideration of the premises and the agreements,
provisions and covenants herein contained, the parties hereto agree as follows:

                                       1
<PAGE>

            SECTION 1. AMENDMENTS TO THE CREDIT AGREEMENT

1.1   AMENDMENTS TO SECTION 1: DEFINITIONS

            Subsection 1.1 of the Credit Agreement is hereby amended by adding
thereto the following definitions, which shall be inserted in proper
alphabetical order:

            "CANADIAN CREDIT AGREEMENT" means that certain Credit Facility
      Agreement dated as of May 17, 2004 by and between Pharmaceutical Research
      Associates International, Inc. and Canadian Imperial Bank of Commerce, as
      lender, as such agreement may be amended, supplemented, or otherwise
      modified from time to time.

            "CANADIAN SUBSIDIARY GUARANTORS" means Pharmaceutical Research
      Associates Inc. and Pharm Research Associates RX, Inc.

            "FIRST AMENDMENT EFFECTIVE DATE" means the effective date of that
      certain First Amendment to Amended and Restated Credit Agreement and
      Certain Other Loan Documents dated as of May 17, 2004 and entered into by
      and among Company, Holdings, PRA Sub, the Subsidiary Guarantors listed on
      the signature pages thereof, the financial institutions listed on the
      signature pages thereof and Administrative Agent.

            "FOREIGN BORROWERS" means Pharmaceutical Research Associates
      International, Inc. and the U.K. Borrowers.

            "FOREIGN FACILITIES GUARANTY" means that certain Foreign Facilities
      Guaranty dated as of May 17, 2004 by Holdings, PRA Sub, Company, and
      Subsidiary Guarantors, as such agreement may be amended, supplemented, or
      otherwise modified from time to time.

            "INTERCREDITOR AGREEMENT" means that certain Intercreditor Agreement
      dated as of May 17, 2004 by and among Administrative Agent, Wachovia Bank,
      National Association, acting through its London branch, in its capacity as
      lender under the U.K. Credit Agreement, and Canadian Imperial Bank of
      Commerce, in its capacity as lender under the Canadian Credit Agreement,
      as such agreement may be amended, supplemented, or otherwise modified from
      time to time.

            "U.K. BORROWERS" means, collectively, Pharmaceutical Research
      Associates, GMBH and Pharm Research Associates (UK) Limited.

            "U.K. CREDIT AGREEMENT" means that certain Multi-Currency Revolving
      Cash Advance, Letter of Credit and Sterling Overdraft Facilities Agreement
      dated May 17, 2004 by and among Pharmaceutical Research Associates, GMBH
      and Pharm Research Associates (U.K.) Limited, as co-borrowers, and
      Wachovia Bank, National

                                       2
<PAGE>

      Association, acting through its London branch, as lender, as such
      agreement may be amended, supplemented, or otherwise modified from time to
      time.

1.2   AMENDMENTS TO SECTION 2: AMOUNTS AND TERMS OF COMMITMENTS AND LOANS

            A.    Subsection 2.1A(i) of the Credit Agreement is hereby amended
by deleting the second sentence thereof and substituting the following therefor:

            "Canadian Imperial Bank of Commerce agrees to lend to Company on the
      First Amendment Effective Date, a Tranche A Term Loan in amount equal to
      $1,666,667. The amount of each Lender's Tranche A Term Loan Commitment as
      of the First Amendment Effective Date is set forth opposite its name on
      Schedule 2.1 annexed hereto and the aggregate amount of the Tranche A Term
      Loan Commitments as of the First Amendment Effective Date is $20,666,667;
      provided that the Tranche A Term Loan Commitments of Lenders shall be
      adjusted to give effect to any assignments of the Tranche A Term Loan
      Commitments pursuant to subsection 10.1B."

            B.    Subsection 2.1A(ii) of the Credit Agreement is hereby amended
by deleting the third sentence thereof and substituting the following therefor:

            "Canadian Imperial Bank of Commerce agrees to lend to Company on the
      First Amendment Effective Date, a Tranche B Term Loan in amount equal to
      $3,333,333. The amount of each Lender's Tranche B Term Loan Commitment as
      of the First Amendment Effective Date is set forth opposite its name on
      Schedule 2.1 annexed hereto and the aggregate amount of the Tranche B Term
      Loan Commitments as of the First Amendment Effective Date is $43,133,333;
      provided that the Tranche B Term Loan Commitments of Lenders shall be
      adjusted to give effect to any assignments of the Tranche B Term Loan
      Commitments pursuant to subsection 10.1B."

            C.    Subsection 2.1A(iii) of the Credit Agreement is hereby
amended by deleting the second sentence thereof and substituting the following
therefor:

            "The original amount of each Revolving Lender's Revolving Loan
      Commitment as of the First Amendment Effective Date is set forth opposite
      its name on Schedule 2.1 annexed hereto and the aggregate original amount
      of the Revolving Loan Commitments as of the First Amendment Effective Date
      is $23,750,000; provided that the Revolving Loan Commitment of Revolving
      Lenders shall be adjusted to give effect to any assignments of the
      Revolving Loan Commitments pursuant to subsection 10.1B and shall be
      reduced from time to time by the amount of any reductions thereto made
      pursuant to subsection 2.4."

            D.    Subsection 2.4A of the Credit Agreement is hereby amended by
deleting it in its entirety and substituting the following therefor:

                                       3
<PAGE>

            "A. SCHEDULED PAYMENTS OF TERM LOANS.

            (i)   Scheduled Payments of Tranche A Term Loans. Company shall make
      principal payments on the Tranche A Term Loans in installments on the
      dates and in the amounts set forth below:

<TABLE>
<CAPTION>
                               Scheduled
Date                           Repayment
----                           ---------
<S>                           <C>
March 31, 2004                $        0
June 30, 2004                 $   42,735
September 30, 2004            $  542,735
December 31, 2004             $  542,735
March 31, 2005                $  814,103
June 30, 2005                 $  814,103
September 30, 2005            $  814,103
December 31, 2005             $  814,103
March 31, 2006                $1,356,838
June 30, 2006                 $1,356,838
September 30, 2006            $1,356,838
December 31, 2006             $1,356,838
March 31, 2007                $1,356,838
June 30, 2007                 $1,356,838
September 30, 2007            $1,356,838
December 31, 2007             $1,356,838
March 31, 2008                $1,356,838
June 30, 2008                 $1,356,838
September 30, 2008            $1,356,838
December 23, 2008             $1,356,838
</TABLE>

      ; provided that the scheduled installments of principal of the Tranche A
      Term Loans set forth above shall be reduced in connection with any
      voluntary or mandatory prepayments of the Tranche A Term Loans in
      accordance with subsection 2.4B(iv); and provided, further that the
      Tranche A Term Loans and all other amounts owed hereunder with respect to
      the Tranche A Term Loans shall be paid in full no later than December 23,
      2008, and the final installment payable by Company in respect of the
      Tranche A Term Loans on such date shall be in an amount, if such amount is
      different from that specified above, sufficient to repay all amounts owing
      by Company under this Agreement with respect to the Tranche A Term Loans.

            (ii) Scheduled Payments of Tranche B Term Loans. Company shall make
      principal payments on the Tranche B Term Loans in installments on the
      dates and in the amounts set forth below:

                                       4
<PAGE>

<TABLE>
<CAPTION>
                             Scheduled
Date                         Repayment
----                         ---------
<S>                        <C>
March 31, 2004             $         0
June 30, 2004              $     8,354
September 30, 2004         $   108,354
December 31, 2004          $   108,354
March 31, 2005             $   108,354
June 30, 2005              $   108,354
September 30, 2005         $   108,354
December 31, 2005          $   108,354
March 31, 2006             $   108,354
June 30, 2006              $   108,354
September 30, 2006         $   108,354
December 31, 2006          $   108,354
March 31, 2007             $   108,354
June 30, 2007              $   108,354
September 30, 2007         $   108,354
December 31, 2007          $   108,354
March 31, 2008             $   108,354
June 30, 2008              $   108,354
September 30, 2008         $   108,354
December 31, 2008          $   108,354
March 31, 2009             $10,293,651
June 30, 2009              $10,293,651
September 30, 2009         $10,293,651
December 23, 2009          $10,293,651
</TABLE>

      ; provided that the scheduled installments of principal of the Tranche B
      Term Loans set forth above shall be reduced in connection with any
      voluntary or mandatory prepayments of the Tranche B Term Loans in
      accordance with subsection 2.4B(iv); and provided, further that the
      Tranche B Term Loans and all other amounts owed hereunder with respect to
      the Tranche B Term Loans shall be paid in full no later than December 23,
      2009, and the final installment payable by Company in respect of the
      Tranche B Term Loans on such date shall be in an amount, if such amount is
      different from that specified above, sufficient to repay all amounts owing
      by Company under this Agreement with respect to the Tranche B Term Loans."

            E.    Subsections 2.4B(iii)(a), (b), (c) and (d) of the Credit
Agreement are hereby amended by inserting the word "Domestic" before the words
"Subsidiary" and "Subsidiaries" each time they appear therein.

                                       5
<PAGE>

1.3   AMENDMENTS TO SECTION 6: COMPANY'S AFFIRMATIVE COVENANTS

            A.    Subsection 6.10 of the Credit Agreement is hereby amended by
deleting the phrase "At all times after the date that is 90 days after the
Closing Date" contained therein and substituting the following therefor:

            "At all times after the date that is 20 days after the First
      Amendment Effective Date (or such later date as agreed by Administrative
      Agent in it sole discretion)"

            B.    Subsection 6.11 of the Credit Agreement is hereby amended by
deleting the phrase "From and after the date that is 90 days after the Closing
Date" contained therein and substituting the following therefor:

            "From and after the date that is 60 days after the First Amendment
      Effective Date (or such later date as agreed by Administrative Agent in it
      sole discretion)"

            C.    Subsection 6.13B of the Credit Agreement is hereby amended by
deleting it in its entirety and substituting the following therefor:

            "B. "Within 90 days of the First Amendment Effective Date or such
      later date agreed by Administrative Agent in its sole discretion,

            (i)   Company shall, and shall cause each of its Domestic
      Subsidiaries to, execute and deliver to Administrative Agent one or more
      Foreign Pledge Agreements with respect to 65% of the Capital Stock owned
      by Company or a Domestic Subsidiary of all Foreign Subsidiaries organized
      under the laws of Canada and the United Kingdom with respect to which
      Administrative Agent deems a Foreign Pledge Agreement necessary or
      advisable to perfect or otherwise protect the First Priority Liens granted
      to Administrative Agent on behalf of Lenders in such Capital Stock, and
      take all such other actions under the laws of such jurisdictions as
      Administrative Agent may deem necessary or advisable to perfect or
      otherwise protect such Liens; provided, however, that no action shall be
      required to be taken by any Loan Party with respect to the Capital Stock
      of any Foreign Subsidiary pursuant to this subsection in the event that
      Company and Administrative Agent agree in good faith that the pledge of
      such Capital Stock would result in an unreasonable tax liability to any
      Loan Party or would otherwise be unduly costly or impracticable; provided
      further, that Lenders and Administrative Agent acknowledge that no Foreign
      Pledge Agreements or other actions shall be deemed necessary or advisable
      in respect of pledged Capital Stock owned as of the First Amendment
      Effective Date by Company or a Domestic Subsidiary of any Foreign
      Subsidiary organized under the laws of France, Germany or Spain; and

            (ii)  Company shall, and shall cause each of its Subsidiaries to,
      deliver to Administrative Agent an original executed intercompany note of
      any and all Foreign Subsidiaries with Indebtedness to any Loan Party in
      favor of all Loan Parties, duly endorsed in a manner satisfactory to
      Administrative Agent."

                                       6
<PAGE>

1.4   AMENDMENTS TO SECTION 7: COMPANY'S NEGATIVE COVENANTS

            A.    Subsection 7.1 of the Credit Agreement is hereby amended by
deleting the word "and" after subsection 7.1(x), by deleting the period after
subsection 7.1(xi) and replacing such period with a semicolon, by renumbering
subsection 7.1(xii) as 7.1(xiv) and by adding new subsections 7.1(xii) and
7.1(xiii) as follows:

            "(xii) Pharmaceutical Research Associates International, Inc. may
      become and remain liable with respect to Indebtedness under the Canadian
      Credit Agreement in an aggregate principal amount not to exceed $3,000,000
      (as such amount is permitted to increase under the Canadian Credit
      Agreement as a result of currency fluctuations) and Holdings, PRA Sub,
      Company, the Subsidiary Guarantors and the Canadian Subsidiary Guarantors
      may become and remain liable with respect to such Indebtedness in the form
      of the Liens granted by such Loan Parties to secure the obligations of
      Pharmaceutical Research Associates International, Inc. thereunder;

            (xiii) U.K. Borrowers may become and remain liable with respect to
      Indebtedness under the U.K. Credit Agreement in an aggregate principal
      amount not to exceed $6,250,000 (as such amount is permitted to increase
      under the U.K. Credit Agreement as a result of currency fluctuations) and
      Holdings, PRA Sub, Company and the Subsidiary Guarantors may become and
      remain liable with respect to such Indebtedness in the form of the Liens
      granted by such Loan Parties to secure the obligations of U.K. Borrowers
      thereunder; and"

            B.    Subsection 7.2A(iv) of the Credit Agreement is hereby amended
      to read in its entirety as follows:

                  "Liens on assets of Foreign Subsidiaries securing Indebtedness
      permitted under subsections 7.1(v) and 7.1(xii); and"

            C.    Subsections 7.2C and 7.2D of the Credit Agreement are hereby
      amended by deleting the phrase "subsection 7.1(v)" each time it appears
      therein and substituting the phrase "subsections 7.1(v), (xii) and
      (xiii)" therefor.

            D.    Subsection 7.3(x) of the Credit Agreement is hereby amended
      by deleting it in its entirety and substituting the following therefor:

            (i)   "Company and its Subsidiaries may acquire by purchase or
      otherwise all or substantially all of the business, property or fixed
      assets of, or Capital Stock of, any Person or any division or line of
      business of any Person (each a "PERMITTED ACQUISITION"); provided that
      either (a) (1) such Person, division or line of business is engaged in the
      businesses engaged in by Company and its Subsidiaries on the Closing Date
      or similar or related businesses, (2) Consolidated EBITDA of such Person,

                                       7
<PAGE>

      division or line of business (calculated in accordance with the definition
      thereof with respect to such Person, division or line of business) shall
      be positive for the most recently completed twelve-month period and
      Company shall have delivered to Administrative Agent financial statements
      with respect to such Person, division or line of business with respect to
      such twelve-month period in form and substance reasonably satisfactory to
      Administrative Agent, (3) the aggregate amount of all consideration
      payable by or on behalf of Company or any of its Subsidiaries in
      connection with all proposed Permitted Acquisitions in Cash, property,
      services, notes, bonds, debentures or other debt instruments, together
      with the aggregate principal amount of all Indebtedness assumed or
      Contingent Obligations incurred by Company or any of its Subsidiaries in
      connection with such Permitted Acquisitions, shall not exceed $10,000,000
      in any Fiscal Year, and (4) Company shall have delivered a Compliance
      Certificate to Administrative Agent demonstrating that, after giving
      effect to such proposed Permitted Acquisition, Company shall be in
      compliance with the requirements of subsection 7.6, or (b) prior to such
      acquisition, Requisite Lenders have specifically consented in writing to
      the terms of such acquisition;"

            E.    Subsection 7.4 of the Credit Agreement is hereby amended by
deleting the word "and" after subsection 7.4(v), by deleting the period after
subsection 7.4(vi) and replacing such period with the phrase "; and", and by
adding a new subsection 7.4(vii) at the end thereof as follows:

            "(vii) Holdings, PRA Sub, Company, and Subsidiary Guarantors may
      become and remain liable with respect to Contingent Obligations in respect
      of the Foreign Facilities Guaranty and Contingent Obligations in the form
      of Liens securing Indebtedness under the Canadian Credit Agreement and the
      U.K. Credit Agreement."

            F.    Subsection 7.9 of the Credit Agreement is hereby amended by
deleting the word "and" after clause (v) and adding the following before the
period at the end of clause (vi) thereof:

            ", and (vii) Indebtedness permitted under subsections 7.1(xii) and
      (xiii) and Contingent Obligations permitted under subsection 7.4(vii)"

1.5   AMENDMENTS TO SECTION 9: ADMINISTRATIVE AGENT

            The first paragraph of subsection 9.6 of the Credit Agreement is
hereby amended by deleting it in its entirety and substituting the following
therefor:

            "Each Lender hereby further authorizes Administrative Agent, on
      behalf of and for the benefit of Lenders, to enter into each Collateral
      Document as secured party, to be the agent for and representative of
      Lenders under each Guaranty and to enter into and be the agent for and
      representative of Lenders under the Intercreditor Agreement and each
      Lender agrees to be bound by the terms of each Collateral Document, each
      Guaranty and the Intercreditor Agreement; provided that

                                       8
<PAGE>

      Administrative Agent shall not (i) enter into or consent to any material
      amendment, modification, termination or waiver of any provision contained
      in any Collateral Document or Guaranty or the Intercreditor Agreement or
      (ii) release any Collateral (except as otherwise expressly permitted or
      required pursuant to the terms of this Agreement or the applicable
      Collateral Document), in each case without the prior consent of Requisite
      Lenders (or, if required pursuant to subsection 10.6, all Lenders);
      provided further, however, that, without further written consent or
      authorization from Lenders, Administrative Agent may execute any documents
      or instruments necessary to (a) release any Lien encumbering any item of
      Collateral that is the subject of a sale or other disposition of assets
      permitted by this Agreement or to which Requisite Lenders have otherwise
      consented, (b) release any Subsidiary Guarantor from the Subsidiary
      Guaranty if all of the Capital Stock of such Subsidiary Guarantor is sold
      to any Person (other than an Affiliate of Company) pursuant to a sale or
      other disposition permitted hereunder or to which Requisite Lenders have
      otherwise consented or (c) subordinate the Liens of Administrative Agent,
      on behalf of Lenders, to any Liens permitted by subsection 7.2; provided
      that, in the case of a sale of such item of Collateral or stock referred
      to in subdivision (a) or (b), the requirements of subsection 10.14 are
      satisfied. Anything contained in any of the Loan Documents to the contrary
      notwithstanding, Company, Administrative Agent and each Lender hereby
      agree that (1) no Lender shall have any right individually to realize upon
      any of the Collateral under any Collateral Document or to enforce any
      Guaranty, it being understood and agreed that all powers, rights and
      remedies under the Collateral Documents and the Guaranties may be
      exercised solely by Administrative Agent for the benefit of Lenders in
      accordance with the terms thereof, and (2) in the event of a foreclosure
      by Administrative Agent on any of the Collateral pursuant to a public or
      private sale, Administrative Agent or any Lender may be the purchaser of
      any or all of such Collateral at any such sale and Administrative Agent,
      as agent for and representative of Lenders (but not any Lender or Lenders
      in its or their respective individual capacities unless Requisite Lenders
      shall otherwise agree in writing) shall be entitled, for the purpose of
      bidding and making settlement or payment of the purchase price for all or
      any portion of the Collateral sold at any such public sale, to use and
      apply any of the Obligations as a credit on account of the purchase price
      for any collateral payable by Administrative Agent at such sale."

1.6   SUBSTITUTION OF SCHEDULE

            Schedule 2.1 to the Credit Agreement is hereby amended by deleting
said Schedule 2.1 in its entirety and substituting in place thereof a new
Schedule 2.1 in the form of Schedule 2.1 to this Amendment.

1.7   LIMITED WAIVER

            Subject to the terms and conditions set forth herein and in reliance
on the representations and warranties of Company herein contained, Lenders
hereby waive compliance with the provisions of subsections 6.10, 6.11 and 6.13
of the Credit Agreement for the period from and including March 23, 2004 to and
including May 17, 2004. Without limiting the generality of the provisions of
subsection 10.6 of the Credit Agreement, the

                                       9
<PAGE>

waiver set forth above shall be limited precisely as written and relates solely
to the noncompliance by Company with the provisions of subsections 6.10, 6.11
and 6.13 of the Credit Agreement in the manner and to the extent described
above, and nothing herein shall be deemed to constitute a waiver of compliance
by Company with respect to (i) subsections 6.10, 6.11 and 6.13 of the Credit
Agreement in any other instance or (ii) any other term, provision or condition
of the Credit Agreement or any other instrument or agreement referred to
therein.

                  SECTION 2. AMENDMENTS TO THE AMENDED AND RESTATED HOLDINGS
PLEDGE AGREEMENT

2.1   AMENDMENTS TO SECTION 2: SECURITY FOR OBLIGATIONS

            Section 2 of the Holdings Pledge Agreement is hereby amended by
deleting it in its entirety and substituting the following therefor:

      " SECTION 2. SECURITY FOR OBLIGATIONS. This Agreement secures, and the
      Pledged Collateral pledged by each Pledgor is collateral security for, the
      prompt payment or performance in full when due, whether at stated
      maturity, by required prepayment, declaration, acceleration, demand or
      otherwise (including without limitation the payment of amounts that would
      become due but for the operation of the automatic stay under Section
      362(a) of the Bankruptcy Code, 11 U.S.C. Section 362(a)), of all
      obligations and liabilities of every nature of any Pledgor now or
      hereafter existing under or arising out of or in connection with the
      Guaranty and the Foreign Facilities Guaranty, in each case together with
      all extensions or renewals thereof, whether for principal, interest
      (including without limitation interest that, but for the filing of a
      petition in bankruptcy with respect to Company, any Foreign Borrower or
      any other Pledgor, would accrue on such obligations, whether or not a
      claim is allowed against Company or any other Pledgor for such interest in
      the related bankruptcy proceeding), reimbursement of amounts drawn under
      Letters of Credit, payments for early termination of Lender Interest Rate
      Agreements, fees, expenses, indemnities or otherwise, whether voluntary or
      involuntary, direct or indirect, absolute or contingent, liquidated or
      unliquidated, whether or not jointly owed with others, and whether or not
      from time to time decreased or extinguished and later increased, created
      or incurred, and all or any portion of such obligations or liabilities
      that are paid, to the extent all or any part of such payment is avoided or
      recovered directly or indirectly from Secured Party or any Lender or
      Interest Rate Exchanger as a preference, fraudulent transfer or otherwise,
      and all obligations of every nature of Pledgors now or hereafter existing
      under this Agreement (all such obligations of such Pledgor being the
      "SECURED OBLIGATIONS")."

2.2   AMENDMENTS TO SECTION 16: SECURED PARTY AS AGENT

            Subsection 16(a) of the Holdings Pledge Agreement is hereby amended
by deleting it in its entirety and substituting the following therefor:

                                       10
<PAGE>

            "(a) Secured Party has been appointed to act as Secured Party
      hereunder by Lenders and, by their acceptance of the benefits hereof,
      Interest Rate Exchangers. Secured Party shall be obligated, and shall have
      the right hereunder, to make demands, to give notices, to exercise or
      refrain from exercising any rights, and to take or refrain from taking any
      action (including without limitation the release or substitution of
      Pledged Collateral), solely in accordance with this Agreement and the
      Credit Agreement; provided that Secured Party shall exercise, or refrain
      from exercising, any remedies provided for in Section 11 hereof in
      accordance with the instructions of (i) Requisite Lenders, or (ii) after
      payment in full of all Obligations under the Credit Agreement and the
      other Loan Documents, the cancellation or expiration of all Letters of
      Credit and the termination of the Commitments and after payment in full of
      all obligations under the Canadian Credit Agreement and under the U.K.
      Credit Agreement, the cancellation or expiration of all letters of credit
      and letters of guarantee issued under the Canadian Credit Agreement and
      letters of credit and guarantees issued under the U.K. Credit Agreement
      and all bankers' acceptances issued under the Canadian Credit Agreement
      and the termination of the commitments under the Canadian Credit Agreement
      and under the U.K. Credit Agreement, the holders of a majority of (A) the
      aggregate notional amount under all Lender Interest Rate Agreements
      (including Lender Interest Rate Agreements that have been terminated) or
      (B) if all Lender Interest Rate Agreements have been terminated in
      accordance with their terms, the aggregate amount then due and payable
      (exclusive of expenses and similar payments but including any early
      termination payments then due) under such Lender Interest Rate Agreements
      (Requisite Lenders or, if applicable, such holders being referred to
      herein as "REQUISITE OBLIGEES"). In furtherance of the foregoing
      provisions of this Section 16(a), each Interest Rate Exchanger, by its
      acceptance of the benefits hereof, agrees that it shall have no right
      individually to realize upon any of the Pledged Collateral hereunder, it
      being understood and agreed by such Interest Rate Exchanger that all
      rights and remedies hereunder may be exercised solely by Secured Party for
      the benefit of Lenders and Interest Rate Exchangers in accordance with the
      terms of this Section 16(a)."

2.3   GENERAL AMENDMENTS

            On and after the First Amendment Effective Date, (a) each reference
in the Holdings Pledge Agreement to "Secured Party" shall mean Wells Fargo Bank,
National Association as agent for and representative of (i) the Lenders party to
the Credit Agreement, (ii) any Interest Rate Exchangers (as defined in the
Holdings Pledge Agreement), (iii) Canadian Imperial Bank of Commerce, as the
lender under the Canadian Credit Agreement and (iv) Wachovia Bank, National
Association, acting through its London branch, as the lender under the U.K.
Credit Agreement; (b) each reference in the Holdings Pledge Agreement to
"Requisite Lenders" shall mean Requisite Facilities Lenders (as such term is
defined in the Intercreditor Agreement); and (c) each reference in the Holdings
Pledge Agreement to "Lenders" (except in the preliminary statements thereto)
shall mean Lenders, U.K. Lender (as such term is defined in the Intercreditor
Agreement) and Canadian Lender (as such term is defined in the Intercreditor
Agreement).

                                       11
<PAGE>

            SECTION 3. AMENDMENTS TO THE AMENDED AND RESTATED SECURITY AGREEMENT

3.1   AMENDMENTS TO SECTION 2: SECURITY FOR OBLIGATIONS

            Section 2 of the Security Agreement is hereby amended by deleting it
in its entirety and substituting the following therefor:

      "SECTION 2. SECURITY FOR OBLIGATIONS.

                  This Agreement secures, and the Collateral assigned by each
      Grantor is collateral security for, the prompt payment or performance in
      full when due, whether at stated maturity, by required prepayment,
      declaration, acceleration, demand or otherwise (including without
      limitation the payment of amounts that would become due but for the
      operation of the automatic stay under Section 362(a) of the Bankruptcy
      Code), of all Secured Obligations of such Grantor. "SECURED OBLIGATIONS"
      means:

                  (a) with respect to Company, all obligations and liabilities
      of every nature of Company now or hereafter existing under or arising out
      of or in connection with the Credit Agreement, the other Loan Documents,
      any Lender Interest Rate Agreement and the Foreign Facilities Guaranty,
      and

                  (b) with respect to each Subsidiary Grantor and Additional
      Grantor, all obligations and liabilities of every nature of such Grantors
      now or hereafter existing under or arising out of or in connection with
      the Subsidiary Guaranty and the Foreign Facilities Guaranty;

      in each case together with all extensions or renewals thereof, whether for
      principal, interest (including without limitation interest that, but for
      the filing of a petition in bankruptcy with respect to Company, any
      Foreign Borrower or any other Grantor, would accrue on such obligations,
      whether or not a claim is allowed against Company or such Grantor for such
      interest in the related bankruptcy proceeding), reimbursement of amounts
      drawn under Letters of Credit, payments for early termination of Lender
      Interest Rate Agreements, fees, expenses, indemnities or otherwise,
      whether voluntary or involuntary, direct or indirect, absolute or
      contingent, liquidated or unliquidated, whether or not jointly owed with
      others, and whether or not from time to time decreased or extinguished and
      later increased, created or incurred, and all or any portion of such
      obligations or liabilities that are paid, to the extent all or any part of
      such payment is avoided or recovered directly or indirectly from Secured
      Party or any Lender or Interest Rate Exchanger as a preference, fraudulent
      transfer or otherwise, and all obligations of every nature of Grantors now
      or hereafter existing under this Agreement."

3.2   AMENDMENTS TO SECTION 20: SECURED PARTY AS AGENT

            The first paragraph of Section 20 of the Security Agreement is
hereby amended by deleting it in its entirety and substituting the following
therefor:

                                       12
<PAGE>

            "Secured Party has been appointed to act as Secured Party hereunder
      by Lenders and, by their acceptance of the benefits hereof, Interest Rate
      Exchangers. Secured Party shall be obligated, and shall have the right
      hereunder, to make demands, to give notices, to exercise or refrain from
      exercising any rights, and to take or refrain from taking any action
      (including without limitation the release or substitution of Collateral),
      solely in accordance with this Agreement and the Credit Agreement;
      provided that Secured Party shall exercise, or refrain from exercising,
      any remedies provided for in Section 15 hereof in accordance with the
      instructions of (i) Requisite Lenders or (ii) after payment in full of all
      Obligations under the Credit Agreement and the other Loan Documents, the
      cancellation or expiration of all Letters of Credit and the termination of
      the Commitments and after payment in full of all obligations under the
      Canadian Credit Agreement and under the U.K. Credit Agreement, the
      cancellation or expiration of all letter of guarantee and letters of
      credit issued under the Canadian Credit Agreement and letters of credit
      and guarantees issued under the U.K. Credit Agreement and all bankers'
      acceptances issued under the Canadian Credit Agreement and the termination
      of the commitments under the Canadian Credit Agreement and under the U.K.
      Credit Agreement, the holders of a majority of (A) the aggregate notional
      amount under all Lender Interest Rate Agreements (including Lender
      Interest Rate Agreements that have been terminated) or (B) if all Lender
      Interest Rate Agreements have been terminated in accordance with their
      terms, the aggregate amount then due and payable (exclusive of expenses
      and similar payments but including any early termination payments then
      due) under such Lender Interest Rate Agreements (Requisite Lenders or, if
      applicable, such holders being referred to herein as "REQUISITE
      OBLIGEES"). In furtherance of the foregoing provisions of this Section 20,
      each Interest Rate Exchanger, by its acceptance of the benefits hereof,
      agrees that it shall have no right individually to realize upon any of the
      Collateral hereunder, it being understood and agreed by such Interest Rate
      Exchanger that all rights and remedies hereunder may be exercised solely
      by Secured Party for the benefit of Lenders and Interest Rate Exchangers
      in accordance with the terms of this Section 20."

3.3   GENERAL AMENDMENTS

            On and after the First Amendment Effective Date, (a) each reference
in the Security Agreement to "Secured Party" shall mean Wells Fargo Bank,
National Association as agent for and representative of (i) the Lenders party to
the Credit Agreement, (ii) any Interest Rate Exchangers (as defined in the
Security Agreement), (iii) Canadian Imperial Bank of Commerce, as the lender
under the Canadian Credit Agreement and (iv) Wachovia Bank, National
Association, acting through its London branch, as the lender under the U.K.
Credit Agreement; (b) each reference in the Security Agreement to "Requisite
Lenders" shall mean Requisite Facilities Lenders (as such term is defined in the
Intercreditor Agreement); and (c) each reference in the Security Agreement to
"Lenders" (except in the preliminary statements thereto) shall mean Lenders,
U.K. Lender (as such term is defined in the Intercreditor Agreement) and
Canadian Lender (as such term is defined in the Intercreditor Agreement).

                                       13
<PAGE>

            SECTION 4. CONDITIONS TO EFFECTIVENESS

            Sections 1, 2, and 3 of this Amendment shall become effective only
upon the satisfaction of all of the following conditions precedent (the date of
satisfaction of such conditions being referred to herein as the "FIRST AMENDMENT
EFFECTIVE DATE"):

            A. On or before the First Amendment Effective Date, each Loan Party
shall deliver to Lenders (or to Administrative Agent for Lenders) the following,
each, unless otherwise noted, dated the First Amendment Effective Date:

                  1.    Certified copies of its Certificate or Articles of
      Incorporation, together with a good standing certificate from the
      Secretary of State of its state of incorporation, each dated a recent date
      prior to the First Amendment Effective Date;

                  2.    A certificate, dated as of the First Amendment Effective
      Date, of its corporate secretary or an assistant secretary, certifying
      that there have been no changes in its Bylaws from the form of Bylaws
      previously delivered to Lenders;

                  3.    Resolutions of its Board of Directors approving and
      authorizing the execution, delivery, and performance of this Amendment and
      approving and authorizing the execution, delivery and payment of the
      Notes, certified as of the First Amendment Effective Date by its corporate
      secretary or an assistant secretary as being in full force and effect
      without modification or amendment;

                  4.    Signature and incumbency certificates of its officers
      executing this Amendment and the Notes delivered hereunder; and

                  5.    Executed copies of this Amendment and any Notes
      requested by any of the Lenders.

            B. On or before the First Amendment Effective Date, Administrative
Agent shall have received executed counterparts of this Amendment from
Supermajority Lenders and each Lender increasing its Commitments.

            SECTION 5. COMPANY'S REPRESENTATIONS AND WARRANTIES

            In order to induce Lenders to enter into this Amendment and to amend
the Credit Agreement in the manner provided herein, Company represents and
warrants to each Lender that the following statements are true, correct and
complete:

            A.    CORPORATE POWER AND AUTHORITY. Each Loan Party has all
requisite corporate power and authority to enter into this Amendment and to
carry out the transactions contemplated by, and perform its obligations under,
the Credit Agreement, the Holdings Pledge Agreement and the Security Agreement,
in each case as amended by this Amendment (the "AMENDED AGREEMENTS").

                                       14
<PAGE>

            B.    AUTHORIZATION OF AGREEMENTS. The execution and delivery of
this Amendment and the performance of the Amended Agreements have been duly
authorized by all necessary corporate action on the part of each Loan Party, as
the case may be.

            C.    NO CONFLICT. The execution and delivery by each Loan Party of
this Amendment and the performance by each Loan Party of the Amended Agreements
do not and will not (i) violate any provision of any law or any governmental
rule or regulation applicable to any Loan Party, the Certificate or Articles of
Incorporation or Bylaws of any Loan Party or any order, judgment or decree of
any court or other agency of government binding on any Loan Party, (ii) conflict
with, result in a breach of or constitute (with due notice or lapse of time or
both) a default under any Contractual Obligation of Company or any of its
Subsidiaries, (iii) result in or require the creation or imposition of any Lien
upon any of the properties or assets of any Loan Party (other than Liens created
under any of the Loan Documents in favor of Administrative Agent on behalf of
Lenders, Canadian Lender and U.K. Lender), or (iv) require any approval of
stockholders or any approval or consent of any Person under any Contractual
Obligation of Company or any of its Subsidiaries.

            D.    GOVERNMENTAL CONSENTS. The execution and delivery by each Loan
Party of this Amendment and the performance by each Loan Party of the Amended
Agreements do not and will not require any registration with, consent or
approval of, or notice to, or other action to, with or by, any federal, state or
other governmental authority or regulatory body.

            E.    BINDING OBLIGATION. This Amendment has been duly executed and
delivered by each Loan Party and this Amendment and each of the Amended
Agreements are the legally valid and binding obligations of each Loan Party
party thereto, enforceable against Company in accordance with their respective
terms, except as may be limited by bankruptcy, insolvency, reorganization,
moratorium or similar laws relating to or limiting creditors' rights generally
or by equitable principles relating to enforceability.

            F.    INCORPORATION OF REPRESENTATIONS AND WARRANTIES FROM CREDIT
AGREEMENT. The representations and warranties contained in Section 5 of the
Credit Agreement are and will be true, correct and complete in all material
respects on and as of the First Amendment Effective Date to the same extent as
though made on and as of that date, except to the extent such representations
and warranties specifically relate to an earlier date, in which case they were
true, correct and complete in all material respects on and as of such earlier
date.

            G.    ABSENCE OF DEFAULT. No event has occurred and is continuing or
will result from the consummation of the transactions contemplated by this
Amendment that would constitute an Event of Default or a Potential Event of
Default.

            SECTION 6. ACKNOWLEDGEMENT AND CONSENT

            Each Loan Party hereby acknowledges and agrees that any of the
Guaranties and Collateral Documents (each, a "CREDIT SUPPORT DOCUMENT") to which
it is a party or otherwise bound shall continue in full force and effect and
that all of its obligations

                                       15
<PAGE>

thereunder shall be valid and enforceable and shall not be impaired or limited
by the execution or effectiveness of this Amendment, except in each case to the
extent expressly modified hereby. Each Loan Party represents and warrants that
all representations and warranties contained in the Amended Agreement and the
Credit Support Documents to which it is a party or otherwise bound are true,
correct and complete in all material respects on and as of the First Amendment
Effective Date to the same extent as though made on and as of that date, except
to the extent such representations and warranties specifically relate to an
earlier date, in which case they were true, correct and complete in all material
respects on and as of such earlier date.

            Each Loan Party (other than Company) acknowledges and agrees that
(i) notwithstanding the conditions to effectiveness set forth in this Amendment,
such Loan Party is not required by the terms of the Credit Agreement or any
other Loan Document to consent to the amendments to the Credit Agreement
effected pursuant to this Amendment and (ii) nothing in the Credit Agreement,
this Amendment or any other Loan Document shall be deemed to require the consent
of such Loan Party to any future amendments to the Credit Agreement.

            The parties hereby acknowledge that Pharm. Research Associates,
Inc., a Delaware corporation ("PHARM") has been dissolved and agree that Pharm
has been or is hereby released as a party from each Loan Document to which it
was a party, including, without limitation, the Subsidiary Guaranty and the
Security Agreement.

            SECTION 7. MISCELLANEOUS

            A.    REFERENCE TO AND EFFECT ON THE CREDIT AGREEMENT AND THE OTHER
LOAN DOCUMENTS.

            (i)   On and after the First Amendment Effective Date, each
      reference in the Credit Agreement, the Security Agreement and the Holdings
      Pledge Agreement to "this Agreement", "hereunder", "hereof", "herein" or
      words of like import referring to the Credit Agreement, the Security
      Agreement or the Holdings Pledge Agreement, as the case may be, and each
      reference in the other Loan Documents to the "Credit Agreement", "Security
      Agreement", "Holdings Pledge Agreement", "thereunder", "thereof" or words
      of like import referring to the Credit Agreement, the Security Agreement
      or the Holdings Pledge Agreement, as the case may be, shall mean and be a
      reference to the corresponding Amended Agreement.

            (ii)  Except as specifically amended by this Amendment, the Credit
      Agreement and the other Loan Documents shall remain in full force and
      effect and are hereby ratified and confirmed.

            (iii) The execution, delivery and performance of this Amendment
      shall not, except as expressly provided herein, constitute a waiver of any
      provision of, or operate as a waiver of any right, power or remedy of
      Administrative Agent or any Lender under, the Credit Agreement or any of
      the other Loan Documents.

                                       16
<PAGE>

                  B.    FEES AND EXPENSES. Company acknowledges that all
reasonable, out-of-pocket costs, fees and expenses as described in subsection
10.2 of the Credit Agreement incurred by Administrative Agent and its counsel
with respect to this Amendment and the documents and transactions contemplated
hereby shall be for the account of Company.

                  C.    HEADINGS. Section and subsection headings in this
Amendment are included herein for convenience of reference only and shall not
constitute a part of this Amendment for any other purpose or be given any
substantive effect.

                  D.    APPLICABLE LAW. THIS AMENDMENT AND THE RIGHTS AND
OBLIGATIONS OF THE PARTIES HEREUNDER SHALL BE GOVERNED BY, AND SHALL BE
CONSTRUED AND ENFORCED IN ACCORDANCE WITH, THE INTERNAL LAWS OF THE STATE OF NEW
YORK (INCLUDING WITHOUT LIMITATION SECTION 5-1401 OF THE GENERAL OBLIGATIONS LAW
OF THE STATE OF NEW YORK), WITHOUT REGARD TO CONFLICTS OF LAWS PRINCIPLES.

                  E.    COUNTERPARTS; EFFECTIVENESS. This Amendment may be
executed in any number of counterparts and by different parties hereto in
separate counterparts, each of which when so executed and delivered shall be
deemed an original, but all such counterparts together shall constitute but one
and the same instrument; signature pages may be detached from multiple separate
counterparts and attached to a single counterpart so that all signature pages
are physically attached to the same document. This Amendment (other than the
provisions of Sections 1, 2 and 3 hereof, the effectiveness of which is governed
by Section 4 hereof) shall become effective upon the execution of a counterpart
hereof by Company, each other Loan Party, Supermajority Lenders and each Lender
increasing its Commitment and receipt by Company and Administrative Agent of
written or telephonic notification of such execution and authorization of
delivery thereof.

                  [Remainder of page intentionally left blank]

                                       17
<PAGE>

            IN WITNESS WHEREOF, the parties hereto have caused this Amendment to
be duly executed and delivered by their respective officers thereunto duly
authorized as of the date first written above.

                                PRA INTERNATIONAL, INC.

                                By:    /s/ PATRICK K DONNELLY
                                       -------------------------------------
                                Name:  Patrick K Donnelly
                                       -------------------------------------
                                Title: President and Chief Executive Officer
                                       -------------------------------------

                                       S-1
<PAGE>

AGREED:

PRA HOLDINGS, INC.

By:    /s/ PATRICK K DONNELLY
       -------------------------------------
Name:  Patrick K Donnelly
       -------------------------------------
Title: President and Chief Executive Officer
       -------------------------------------

PRA SUB, INC.

By:    /s/ PATRICK K DONNELLY
       -------------------------------------
Name:  Patrick K Donnelly
       -------------------------------------
Title: President and Chief Executive Officer
       -------------------------------------

PHARMACEUTICAL RESEARCH ASSOCIATES, INC.

By:    /s/ PATRICK K DONNELLY
       -------------------------------------
Name:  Patrick K Donnelly
       -------------------------------------
Title: President and Chief Executive Officer
       -------------------------------------

INTERNATIONAL MEDICAL TECHNICAL CONSULTANTS, INC.

By:    /s/ PATRICK K DONNELLY
       -------------------------------------
Name:  Patrick K Donnelly
       -------------------------------------
Title: President and Chief Executive Officer
       -------------------------------------

MFH, INC.

By:    /s/ PATRICK K DONNELLY
       -------------------------------------
Name:  Patrick K Donnelly
       -------------------------------------
Title: President and Chief Executive Officer
       -------------------------------------

                                      S-2
<PAGE>

                                        WELLS FARGO BANK, NATIONAL
                                        ASSOCIATION,
                                        individually and as Administrative Agent

                                        By: /s/ JOHN HUKART
                                           ---------------------------------
                                        Name:   John Hukart
                                              ------------------------------

                                        Title:  Vice President
                                              ------------------------------


                                       S-3
<PAGE>

                                        BNP PARIBAS,
                                        as a Lender

                                        By: /s/ ERIC TOIZER
                                           -----------------------------------
                                        Name: Eric Toizer
                                             ---------------------------------
                                        Title: Managing Director
                                              --------------------------------

                                        and

                                        By: /s/ SUSAN BOWES
                                           -----------------------------------
                                        Name: Susan Bowes
                                             ---------------------------------
                                        Title: Director
                                              --------------------------------


                                       S-4
<PAGE>

                                        GENERAL ELECTRIC CAPITAL
                                        CORPORATION,
                                        as a Lender


                                        By: /s/ STEVE J. WARNER
                                           -----------------------------------
                                        Name: Steve J. Warner
                                             ---------------------------------
                                        Title: Duly Authorized Signatory
                                              --------------------------------

                                       S-5
<PAGE>

                                        WACHOVIA BANK, NATIONAL
                                        ASSOCIATION,
                                        as a Lender


                                        By: /s/ MONICA SEVILA
                                           -----------------------------------
                                        Name: Monica Sevila
                                             ---------------------------------
                                        Title: Vice President
                                              --------------------------------

                                      S-6
<PAGE>

                                        CIBC, INC.,
                                        as a Lender


                                        By: /s/ DOMINIC J. SORRESSO
                                           -----------------------------------
                                        Name: Dominic J. Sorresso
                                             ---------------------------------
                                        Title: Executive Director
                                              --------------------------------
                                        CIBC World Markets Corp., as Agent


                                      S-7
<PAGE>

                                  SCHEDULE 2.1

                    LENDERS' COMMITMENTS AND PRO RATA SHARES

<TABLE>
<CAPTION>
                  Tranche A        Pro Rata Share          Tranche B         Pro Rata Share       US Revolving       Pro Rata Share
                  Term Loan        (re: Tranche A          Term Loan         (re: Tranche B         Loan              (re: US Rev.
Lender           Commitment          Term Loans)           Commitment          Term Loans)         Commitment            Loans)
<S>           <C>                  <C>                 <C>                   <C>               <C>                   <C>
Wells
Fargo
Bank,
National
Association   $      294,117.66      1.423149948%      $   20,777,941.18      48.171424672%    $   3,676,470.58      15.479876126%

Wachovia
Bank,
National
Association   $    8,250,000.00     39.919354839%      $    3,725,000.00      8.636012365%     $   6,250,000.00      26.315789474%

BNP
Paribas       $    3,352,941.17     16.223908897%      $    7,023,529.41      16.283298483%    $   4,411,764.71      18.575851411%

General
Electric
Capital
Corporation   $    3,352,941.17     16.223908897%      $    7,023,529.41      16.283298483%    $   4,411,764.71      18.575851411%

CIBC,
Inc.          $    5,416,666.67     26.209677419%      $    4,583,333.33      10.625965997%    $   5,000,000.00      21.052631579%
                 --------------     --------------          ------------      -------------       -------------      --------------
Total         $   20,666,666.67              100%      $   43,133,333.33               100%    $  23,750,000.00               100%
</TABLE>

                                  Schedule 2.1