<PAGE>
                                                                   Exhibit 10.49


                      SECOND AMENDMENT TO CREDIT AGREEMENT

            This SECOND AMENDMENT TO CREDIT AGREEMENT (this "Amendment") is
dated as of May 16,2003, and entered into by and among ALLERGAN, INC. (the
"Company"), the banks and other financial institutions signatory hereto that are
parties as Banks to the Credit Agreement referred to below (the "Banks"),
JPMORGAN CHASE BANK, as administrative agent (in such capacity, the
"Administrative Agent"), CITICORP USA INC., as syndication agent, and BANK OF
AMERICA, N.A., as documentation agent.

                                    Recitals

            A.    The Company, the Banks, and the Agents have entered into that
certain Credit Agreement dated as of October 11, 2002, (as amended by the First
Amendment thereto dated as of October 30, 2002, the "Credit Agreement"), by and
among the Company, the Eligible Subsidiaries referred to therein, the Banks
party thereto, the Administrative Agent, Citicorp USA Inc., as syndication
agent, and Bank of America, N.A., as documentation agent. Capitalized terms used
in this Amendment without definition shall have the meanings given such terms in
the Credit Agreement.

            B.    The Company has requested a certain amendment to the Credit
Agreement.

            C.    The Banks and the Administrative Agent are willing to agree to
the amendment requested by the Company, on the terms and conditions set forth in
this Amendment.

                                    Agreement

            NOW THEREFORE, in consideration of the premises and the mutual
agreements set forth herein, the Company, the Banks, and the Administrative
Agent agree as follows:

            1.    Amendment to Section 1.01 of the Credit Agreement. The
definition of Consolidated Net Worth contained in Section 1.01 of the Credit
Agreement is hereby amended in its entirety to read as follows:

                  "Consolidated Net Worth" means at any date (i) the
      consolidated stockholders' equity of the Company and its Consolidated
      Subsidiaries determined as of such date less (ii) (to the extent reflected
      in determining such consolidated stockholders' equity) all write-ups
      (other than write-ups resulting from foreign currency translations and
      write-ups of assets of a going concern business made within twelve months
      after the acquisition of such business) subsequent to June 28, 2002 in the
      book value of any asset owned by the Company or a Consolidated Subsidiary
      plus (iii) the amount of the reduction in such consolidated stockholders'
      equity which results directly from the lump sum payment made pursuant to
      the Settlement Agreement between the Company, et. al., on the one hand,
      and Pharmacia Corporation, et. al., and Columbia University, on the other
      hand, dated October 2002, resolving intellectual property disputes
      involving Lumigan(R) and the lump sum payment relating thereto; provided
      that the amount of the addition pursuant to this clause (iii) shall not
      exceed $100,000,000, plus (iv) the amount of the reduction in such
      consolidated stockholders' equity which results directly from the
<PAGE>
      in process research and development charge related to the Company's
      acquisition of Bardeen Sciences Company LLC; provided, however, that the
      amount of the addition pursuant to this clause (iv) shall not exceed
      $260,000,000.

            2.    Representations and Warranties. The Company represents and
warrants that:

                  (a)   Corporate Existence and Power. The Company is a
      corporation duly incorporated, validly existing and in good standing under
      the laws of Delaware, and has all corporate powers and all material
      governmental licenses, authorizations, consents and approvals required to
      carry on its business as now conducted.

                  (b)   Corporate and Governmental Authorization. The execution,
      delivery and performance by the Company of this Amendment and the
      performance by the Company of the Credit Agreement, as amended by this
      Amendment (the "Amended Credit Agreement"), are within the Company's
      corporate powers, have been duly authorized by all necessary corporate
      action, require no action by or in respect of, or filing with, any
      governmental body, agency or official under any provision of law or
      regulation applicable to the Company, and do not contravene, or constitute
      a default under, any provision of law or regulation applicable to the
      Company or of the restated certificate of incorporation or by-laws of the
      Company or of any agreement, judgment, injunction, order, decree or other
      instrument binding upon the Company or any of its Subsidiaries or result
      in the creation or imposition of any Lien on any asset of the Company or
      any of its Subsidiaries.

                  (C)   Binding Effect. This Amendment and the Amended Credit
      Agreement constitute the legal, valid and binding obligations of the
      Company.

                  (d)   No Default. Immediately before and after giving effect
      to this Amendment, no Default has occurred and is continuing.

      3.    Effectiveness. This Amendment shall be effective on the date when
this Amendment shall have been signed, and counterparts hereof shall have been
delivered to the Administrative Agent (by hand delivery, mail or telecopy), by
the Company and the Required Banks.

      4.    Effect of Amendment; Ratification. From and after the date on which
this Amendment becomes effective, all references to the Credit Agreement shall
mean the Credit Agreement as amended hereby. Except as expressly amended hereby
or waived herein, the Credit Agreement and the Notes shall remain in full force
and effect, and all terms and provisions thereof are hereby ratified and
confirmed. The Company confirms that as amended hereby, each of the Amended
Credit Agreement and the Notes is in full force and effect.

      5.    Governing Law. This Amendment shall be governed by and construed in
accordance with the laws of the State of New York.

      6.    Counterparts; Integration. This Amendment may be signed in any
number of counterparts, each of which shall be an original, with the same effect
as if the signatures


                                        2
<PAGE>
thereto and hereto were upon the same instrument. This Amendment constitutes the
entire agreement and understanding among the parties hereto and supersedes and
any all prior agreements and understandings, oral or written, related to the
subject matter hereof.


                                       3
<PAGE>
            IN WITNESS WHEREOF, each OF the undersigned has duly executed this
Second Amendment to Credit Agreement as OF the date set forth above.


                                       ALLERGAN, INC.


                                       By: /s/ Eric K. Brandt
                                           --------------------------------
                                           Name:  Eric K. Brandt
                                           Title: Corporate Vice President,
                                                  Chief Financial Officer

                                       By: /s/ James M. Hindman
                                           --------------------------------
                                           Name:  James M. Hindman
                                           Title: Senior Vice President,
                                           Treasury, Risk and Investor Relations


                                       JPMORGAN CHASE BANK


                                       By: /s/ Dawn Lee Lum
                                           --------------------------------
                                           Name:  Dawn Lee Lum
                                           Title: Vice President


                                       CITICORP USA, INC.


                                       By: /s/ Carolyn Wendler
                                           --------------------------------
                                           Name:  Carolyn Wendler
                                           Title: Managing Director & VP

                                       By:
                                           --------------------------------
                                           Name:
                                           Title:


                                       BANK OF AMERICA, N.A.


                                       By: /s/ Kevin P. Bertelsen
                                           --------------------------------
                                           Name:  Kevin P. Bertelsen
                                           Title: Vice President


                                       S-1
<PAGE>
                                       BANK ONE, NA


                                       By: /s/ L. Richard Schiller
                                           --------------------------------
                                           Name:  L. Richard Schiller
                                           Title: Director


                                      S-2
<PAGE>
                                       ABN-AMRO BANK N.V.


                                       By: /s/ Neil R. Stein
                                           --------------------------------
                                           Name:  Neil R. Stein
                                           Title: Group Vice President


                                       By: /s/ Michele R. Costello
                                           --------------------------------
                                           Name:  Michele R. Costello
                                           Title: Assistant Vice President


                                      S-3