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                                  EXHIBIT 4.13


                                AMENDMENT NO.3

     THIS AMENDMENT NO.3, dated as of October______, 1997 (the "Amendment") 
                                                                ---------
relating to the Credit Agreement referenced below, by and among AMERISOURCE 
CORPORATION, a Delaware corporation, certain subsidiaries and affiliates party
to the Credit Agreement and identified on the signature pages hereto, and
NATIONSBANK, N.A., as Administrative Agent for and on behalf of the Lenders.
Terms used but not otherwise defined shall have the meanings provided in the
Credit Agreement.

                              W I T N E S S E T H

     WHEREAS, a $500 million credit facility has been extended to AmeriSource 
Corporation pursuant to the terms of that Credit Agreement dated as of January 
8, 1997 (as amended and modified, the "Credit Agreement") among AmeriSource 
                                       ----------------
Corporation, the Guarantors and Lenders identified therein, and NationsBank, 
N.A., as Administrative Agent;

     WHEREAS, the Borrower plans to enter into liquidity financing to provide 
for general corporate purposes, including the build-up of inventory and 
receivables;

     WHEREAS, the Company has requested certain modifications described herein 
connection therewith which require the consent of the Required Lenders; and

     WHEREAS, the Required Lenders have consented to the requested modifications
on the terms and conditions set forth herein and have authorized the
Administrative Agent to enter into this Amendment on their behalf to give effect
to this Amendment;

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

     A.   The Credit Agreement is amended and modified in the following 
respects:

               1.   Section 1.1 shall be amended to include the following 
additional terms (or such existing terms shall be amended to read as follows):

               "Borrowing Base" means, at any time, an amount equal to (i) 
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     seventy percent (70%) of Eligible Inventory minus (ii) Obligations
                                                 -----
     outstanding under the Liquidity Facility.

               "Debt Transaction" means, other than the Liquidity Facility which
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shall not be included within this definition, with respect to any member of the
Consolidated Group, any sale, issuance or placement of Funded Debt, whether or
not evidenced by promissory note or other written evidence of indebtedness.


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          "Liquidity Facility" means such term as defined in Section 8.1(j).
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          "Liquidity Intercreditor Agreement" means that Intercreditor Agreement
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     to be executed relating to the Liquidity Facility and the Obligations under
     this Credit Agreement, among NationsBank, N.A., as Administrative Agent
     under this Credit Agreement, NationsBank, N.A., as Administrative Agent
     under the Liquidity Facility, and the Credit Parties, as amended and
     modified.

          2.   The definition of "Credit Documents" in Section 1.1 shall be 
amended to include "the Liquidity Intercreditor Agreement".

          3.   In the definition of "Permitted Liens" in Section 1.1, subsection
(xviii) is amended to read as follows:

          (xviii)  Liens to secure the Liquidity Facility referenced in Section 
     8.1(j), provided that any such property pledged or securing such Liquidity
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     Facility shall also be pledged to secure the Obligations hereunder and such
     Liens shall be the subject of the Liquidity Intercreditor Agreement
     relating to the Liquidity Facility and the Obligations hereunder providing,
     among other things, that such Liens will be shared by the Lenders hereunder
     and the Lenders under the Liquidity Facility, respectively, on a pari passu
     basis.

          4.   In Section 8.1, subsection (j) shall be amended to read as 
follows:

          (j)  other senior secured Indebtedness of the Borrower in an aggregate
     principal amount of up to $100,000,000 incurred pursuant to that Credit
     Agreement dated as of October____, 1997, among the Borrower, the Guarantors
     and Lenders identified therein and NationsBank, N.A. (the "Liquidity
                                                                ---------
     Facility"); and
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          6.   In Section 8.9(b) the reference at the end to "except to the
extent permitted by Section 8.10." is amended to read as follows:

     "except as relates to the Liquidity Facility and to the extent permitted by
     Section 8.10."

          7.   In Section 8.12, the "and" immediately preceding clause (iii) is
deleted and there shall be inserted at the end of clause (iii) immediately
following the reference to "Section 8.4(c)" the following:

     ", and (iv) the Liquidity Facility,"

          8.   In Section 9.1, in subsection (j) the "." at the end of such
subsection is replaced with the phrase "; or" and a new subsection (k) is added
to read as follows:

          (k)  Liquidity Facility. The occurrence and continuance of an Event of
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     Default under the Liquidity Facility.

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     B.   By execution of the Consent relating to this Amendment, the Required 
Lenders authorize and direct the Administrative Agent, on behalf of the Lenders 
under the Credit Agreement, to enter into the Liquidity Agreement with the 
Credit Parties referred to therein and the Lenders under the Liquidity Facility,
or the Administrative Agent for the Lenders under the Liquidity Facility, in 
substantially the form attached as Exhibit A.
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     C.   Except as modified hereby, all of the terms and provisions of the 
Credit Agreement (and Exhibits and Schedules) remain in full force and effect.

     D.   The Company agrees to pay all reasonable costs and expenses of the 
Administrative Agent in connection with the preparation, execution and delivery 
of this Amendment, including without limitation the reasonable fees and expenses
of Moore & Van Allen, PLLC.

     E.   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.

     F.   This Amendment, and the Credit Agreement as amended hereby, shall be 
governed by and construed and interpreted in accordance with the laws of the 
State of North Carolina.

                 [Remainder of Page Intentionally Left Blank]

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     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:                AMERISOURCE CORPORATION,
--------
                         a Delaware corporation

                         By:___________________________
                         Name:
                         Title:

GUARANTORS:              AMERISOURCE HEALTH CORPORATION,
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                         a Delaware corporation

                         By:___________________________
                         Name:
                         Title:

                         AMERISOURCE HEALTH SERVICES CORP.,
                         a Delaware corporation

                         By:___________________________
                         Name:
                         Title:

                         AMERISOURCE SALES CORPORATION,
                         a Delaware corporation

                         By:___________________________
                         Name:
                         Title:

                         HEALTH SERVICES CAPITAL CORP.,
                         a Delaware corporation

                         By:___________________________
                         Name:
                         Title:
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                         HEALTH SERVICES PLUS, INC.,
                         a Delaware corporation

                         By:_________________________
                         Name:
                         Title:

                         SKYLAND HOSPITAL SUPPLY, INC.,
                         a Tennessee corporation

                         By:_________________________
                         Name:
                         Title:
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ADMINISTRATIVE
AGENT:                  NATIONSBANK, N.A.,
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                        as Administrative Agent for and on behalf of the Lenders

                        By:_____________________________
                        Name:
                        Title: