<PAGE>
 
EXHIBIT 10.5A
                    FIRST AMENDMENT TO EMPLOYMENT AGREEMENT
                    ---------------------------------------


     This First Amendment dated as of September 27, 1996, is to the Employment
Agreement between Value Health, Inc. (the "Company") and Robert E. Patricelli
(the "Executive"), dated as of September 1, 1993 ("Employment Agreement").

                              W I T N E S S E T H
                              - - - - - - - - - -

     WHEREAS, the Company and the Executive desire to amend the Employment
Agreement as follows, as permitted under Section 14 of the Employment Agreement:

     1.   Section 8 of the Employment Agreement is hereby deleted and the
following is added in its place:

          8.   TERMINATION AFTER A STRATEGIC TRANSACTION. In the event of a
               "Strategic Transaction" of the Company (as defined in Section 17
               of this Agreement), if, within twenty-four (24) months following
               the closing of such Strategic Transaction (or at any time prior
               thereto but in contemplation thereof): (i) the Executive is
               terminated without cause; (ii) the Executive is not retained in
               an executive position of responsibility, authority and
               compensation comparable in all material respects to the position
               of the Executive immediately prior to the Strategic Transaction;
               (iii) the Executive does not retain all rights and privileges
               accorded under this Agreement as a result of the Strategic
               Transaction; (iv) the Executive terminates his employment with
               the Company due to either a material reduction in responsibility,
               authority or compensation, or a requirement that the Executive
               relocate, each on account of the Strategic Transaction; then the
               Executive shall receive within five (5) business days following
               the date of termination, a lump sum payment (less all amounts
               required to be withheld and deducted) equal to 3 times the sum of
               the Executive's then current base compensation and annual
               performance bonus at the target level for the year in which such
               termination occurs, and the Executive shall be deemed to have
               been terminated without cause for purposes of Section 7. In
               addition, in the event of a termination of the Executive in
               accordance with the preceding sentence, the Executive shall
               receive the same health benefits available to Company executives,
               upon the same terms and conditions and at the same cost to the
               Executive, for the lesser of one (1) year from the date of
               termination or the first day of the first month in which the
               Executive obtains new employment providing health benefits
               coverage.

     2.   Section 17 is hereby added to the Employment Agreement to read in its
entirety as follows:

               17.  STRATEGIC TRANSACTION. A Strategic Transaction shall be
               deemed to occur if at any time during the term of this Agreement
               any of the following events occur:

                                      71
<PAGE>
 
               (i)    The Company is merged, consolidated or reorganized into or
                      with another corporation or other legal person, and as a
                      result of such merger, consolidation or reorganization,
                      less than 50% of the combined voting power of the then-
                      outstanding securities of such corporation or person
                      immediately after such transaction are held in the
                      aggregate by the holders of Voting Stock (as that term is
                      hereafter defined) of the Company immediately prior to
                      such transaction;

               (ii)   The Company sells or otherwise transfers all or
                      substantially all of its assets to any other corporation
                      or other legal person, and as a result of such sale or
                      transfer, less than 50% of the combined voting power of
                      the then-outstanding voting securities of such corporation
                      or person are held in the aggregate by the holders of
                      Voting Stock of the Company immediately prior to such
                      sale;

               (iii)  There is a report filed on Schedule 13D or Schedule 14D-1
                      (or any successor schedule, form or report), each as
                      promulgated pursuant to the Securities Exchange Act of
                      1934 (the "Exchange Act"), disclosing that any person as
                      the term "person" is used in Section 13(d)(3) or Section
                      14(d)(2) of the Exchange Act) has become the beneficial
                      owner (as the term "beneficial owner" is defined under
                      Rule 13d-3 or any successor rule or regulation promulgated
                      under the Exchange Act) of securities representing 20% or
                      more of the combined voting power of the then-outstanding
                      securities of the Company entitled to vote generally in
                      the election of members of the Board of Directors of the
                      Company ("Voting Stock");

               (iv)   The Company files a report or proxy statement with the
                      Securities and Exchange Commission pursuant to the
                      Exchange Act disclosing in response to Form 8-K or
                      Schedule 14A (or any successor schedule, form or report or
                      item therein) that a strategic transaction of the Company
                      has or may have occurred or will or may occur in the
                      future pursuant to any then-existing contract or
                      transaction;

               (v)    If during the period of two (2) consecutive years
                      individuals who at the beginning of any such period
                      constitute the members of the Board of Directors of the
                      Company (the "Directors") cease for any reason to
                      constitute at least a majority thereof unless the
                      election, or the nomination for election by the Company's
                      shareholders, of each Director first elected during such
                      period was approved by a vote of at least two-thirds of
                      the Directors then still in office who were Directors at
                      the beginning of any such period (excluding for this
                      purpose the election of any new Director in connection
                      with an actual or threatened election of proxy contest);

                                      72
<PAGE>
 
               (vi)   The Company: (i) sells at least 85% of the assets or
                      outstanding stock of a subsidiary to an unrelated party
                      (or completes a transaction having a similar effect), (ii)
                      distributes all or substantially all of the common stock
                      of a subsidiary as a dividend to stockholders of the
                      Company; or (iii) sells voting stock of a subsidiary in an
                      underwritten public offering.

     3.   Section 4 of the Employment Agreement is hereby amended by replacing
the first sentence thereof with the following:

               The Company shall pay the Executive base compensation for his
               services at an annual rate of $682,500.

     4.   Section 18 is hereby added to the Employment Agreement to read in its
entirety as follows:

               18.  Indemnification. If there is a final determination that any
                    ---------------
               portion of the amounts payable to the Executive under the
               Employment Agreement constitutes an "excess parachute payment" as
               such term is used in Section 280G and 4999 of the Internal
               Revenue Code, then the Company shall pay to the Executive an
               additional sum such that after all taxes applicable to the
               receipt of such amount have been subtracted therefrom, the
               remaining amount will equal the sum of the amount of the tax
               imposed with respect to the "excess parachute payment", plus any
               interest and penalties thereon.

     5.   The Employment Agreement, except as herein amended, is hereby
ratified, confirmed and approved in all respects.

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment
Agreement as of the date written above.

                                         Signed on behalf of
                                         Value Health, Inc.

                                         _________________________________


                                         __________________________________
                                         Signed by Robert E. Patricelli

                                      73