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                         AMENDMENT TO SUPPLY AGREEMENT

                  This Amendment to Supply Agreement (this "Amendment") is
entered into as of March 30, 2000, between HORIZON Pharmacies, Inc., a Delaware
corporation ("Horizon"), and McKesson HBOC, Inc., a Delaware corporation
formerly known as McKesson Corporation ("McKesson").

                                    RECITALS

                  WHEREAS, Horizon and McKesson are parties to that certain
Strategic Partnership Supply Agreement dated as of April 30, 1998, as amended by
that certain letter agreement dated April 14, 1999 (as so amended, the "Supply
Agreement"). Capitalized terms used herein without definition shall have the
same meanings herein as set forth in the Supply Agreement.

                  WHEREAS, Horizon has requested certain waivers and consents
under the Supply Agreement and the Credit Agreement dated as of July 2, 1998
between Horizon and Mckesson (as amended from time to time, the "Credit
Agreement"), and McKesson is willing to grant such waivers and consents on
certain terms and conditions, including the execution and delivery of this
Amendment.

                  NOW, THEREFORE, in consideration of the promises and
agreements, provisions and covenants herein contained, and the granting of the
waivers and consents referred to above, the parties hereto agree as follows:

SECTION 1.    AMENDMENT TO SUPPLY AGREEMENT

                  The Supply Agreement is hereby amended by deleting therefrom
the "45 Day Extended Payment Terms" referred to in Section 4.A of the Supply
Agreement, effective as of June 1, 2000. Horizon shall have the choice of the
other options set forth in Section 4.A of the Supply Agreement and agrees that
by June 1, 2000, it will be in full compliance with the option chosen for all
amounts incurred prior to June 1, 2000.

SECTION 2.    MISCELLANEOUS

         A. Reference to and Effect on the Supply Agreement.

                  (i) Each reference in the Supply Agreement to "this
Agreement", "hereunder", "hereof", "herein" or words of like import referring to
the Supply Agreement, and each reference in the Loan Documents (as defined in
the Credit Agreement) to the "Supply Agreement", "thereunder", "thereof" or
words of like import referring to the Supply Agreement shall mean and be a
reference to the Supply Agreement as amended by this Amendment.

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

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         B. COSTS AND EXPENSES. The Horizon covenants to pay to or reimburse
McKesson, upon demand, for all costs, out-of-pocket expenses and reasonable
attorneys' fees expended or incurred by McKesson in connection with the
development, preparation, negotiation, execution and delivery of this Amendment
and the documents and transactions contemplated hereby.

         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 SHALL BE GOVERNED BY, AND SHALL BE
CONSTRUED AND ENFORCED IN ACCORDANCE WITH, THE INTERNAL LAWS OF THE STATE OF
CALIFORNIA, WITHOUT REGARD TO CONFLICTS OF LAWS PRINCIPLES.

         E. COUNTERPARTS. This Amendment may be executed in any number of
counterparts, each of which shall be deemed an original, but all such
counterparts together shall constitute but one and the same instrument. Each of
the parties hereto understands and agrees that this document (and any other
document required herein) may be delivered by any party thereto either in the
form of an executed original or an executed original sent by facsimile
transmission to be followed promptly by mailing of a hard copy original, and
that receipt by a party of a facsimile transmitted document purportedly bearing
the signature of the other party shall bind the other party with the same force
and effect as the delivery of a hard copy original. Any failure by a party to
receive the hard copy executed original of such document shall not diminish the
binding effect of receipt of the facsimile transmitted executed original of such
document of the other party.

                  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.

                             HORIZON PHARMACIES, INC.

                             By:  /s/ Ricky D. McCord
                                ---------------------------------------------
                             Title:  CEO & President
                                   ------------------------------------------

                             McKESSON HBOC, INC.

                             By:     /s/ Alan Pearce
                                ---------------------------------------------
                             Title:  Senior Vice President Financial Services
                                   ------------------------------------------


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