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                                                                   EXHIBIT 10.73

                  AMENDMENT NUMBER ONE TO NOVA HOLDINGS, INC.
                        INCENTIVE STOCK OPTION AGREEMENT


         This Amendment Number One is made and entered into this 6th day of
May, 1999, by and between ACCREDO HEALTH, INCORPORATED, formerly known as Nova
Holdings, Inc. ("Company"), and the EMPLOYEE whose name appears at the end
hereof ("Employee").

         WHEREAS, Pursuant to the Nova Holdings, Inc. and Its Subsidiaries
Stock Option and Restricted Stock Purchase Plan (the "Plan"), Employee was
granted an option to purchase that number of shares of the Company's common
stock, $.01 par value ("Common Stock") as indicated at the end hereof, and the
Company provided Employee with an Incentive Stock Option Agreement
("Agreement") reflecting the date of grant appearing at the end hereof.

         WHEREAS, the option constitutes and is treated as an "Incentive Stock
Option" as defined under Section 422(b) of the Internal Revenue Code of 1986,
as amended; and

         WHEREAS, the Company and the Employee now desire to make certain
changes in the Agreement.

         NOW THEREFORE, for and in exchange of the mutual promises contained
herein and for other good and valuable consideration, the receipt and adequacy
of which is hereby acknowledged, the parties agree that, effective as of the
date first stated above, the Agreement is amended as follows:

         1.       Sections 5.(b) and 5.(c) are amended by deleting those
sections in their entirety and substituting in the place thereof the following:

                  (b)      In the event that Actual EBT (as hereinafter

                  defined) for the full fiscal year ending June 30, 1997 or the
                  full fiscal year ending June 30, 1998, equals or exceeds the
                  Target EBT (as hereinafter defined) for such fiscal year,
                  then, as of the August 1 next following the last day of such
                  fiscal year, you shall become entitled (subject to the
                  calculation of Actual EBT for such fiscal year by the Board
                  of Directors of the Company as provided in Section 5(d)
                  below) to exercise the Option with respect to 25% of the
                  Tranche B Option Shares (rounded to the nearest whole share)
                  until the Option expires and terminates pursuant to Section 2
                  hereof.

                           In the event that Actual FDEPS (as hereinafter
                  defined) for any full fiscal year beginning with the fiscal
                  year ending June 30, 1999, equals or exceeds the Target FDEPS
                  (as hereinafter defined) for such fiscal year, then, as of
                  the August 1 next following the last day of such fiscal year,
                  you shall become entitled (subject to the calculation of
                  Actual FDEPS for such fiscal year by the Board of Directors
                  of the Company as provided in Section 5(d) below) to exercise
                  the Option with


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                  respect to 25% of the Tranche B Option Shares (rounded to the
                  nearest whole share) until the Option expires and terminates
                  pursuant to Section 2 hereof.

                  (c)      In the event that (i) Actual FDEPS (as hereinafter
                  defined) for any of the full fiscal years ending June 30,
                  1997, 1998 and 1999 (the "Shortfall Year") is less than the
                  Target FDEPS for such year, and (ii) the sum of (x) Actual
                  FDEPS for the Shortfall Year, plus (y) Actual FDEPS for the
                  immediately succeeding fiscal year (the "Make-up Year")
                  equals or exceeds the sum of the Target FDEPS for the
                  Shortfall Year and the Make-up Year combined, then, as of the
                  September 1 next following the last day of the Make-up Year,
                  you shall become entitled (subject to the calculation of
                  Actual FDEPS for the Make-up Year by the Board of Directors
                  of the Company as provided in Section 5(d) hereof) to
                  exercise the Option with respect to 25% of the Tranche B
                  Option Shares (rounded to the nearest whole share) until the
                  Option expires and terminates pursuant to Section 2 hereof.
                  Your right to exercise the Option with respect to any Tranche
                  B Option Shares pursuant to this Section 5(c) shall be in
                  addition to your right to exercise the Option with respect to
                  the Make-up Year as provided in Section 5(b) above.

         2.       Section 5(d) is amended by changing the definition of "Target
EBT" to delete the following: "(iii) for the fiscal year ending June 30, 1999 -
$13,300,000.00, and (iv) for the fiscal year ending June 30, 2000 -
$16,600,000.00."

         3.       Section 5(d) is amended by adding the following definitions:

                  "Actual FDEPS" means with respect to any fiscal year ending
                  after June 30, 1998, FDEPS (as hereinafter defined) for such
                  fiscal year as calculated by the Board of Directors of the
                  Company based on the audited consolidated financial
                  statements of the Company and its subsidiaries for such
                  fiscal year, which financial statements shall be conclusive
                  and binding upon the Company and you. "Actual FDEPS" means
                  with respect to any fiscal year ending prior to June 30, 1999
                  Pre-Tax FDEPS (as hereinafter defined) for such fiscal year
                  as calculated by the Board of Directors of the Company based
                  on the audited consolidated financial statements of the
                  Company and its subsidiaries for such fiscal year, which
                  financial statements shall be conclusive and binding upon the
                  Company and you.

                  "Pre-Tax FDEPS" means the pre-tax fully diluted earnings per
                  share with respect to any fiscal year, which shall equal the
                  Net Income Before Taxes (as defined herein) divided by the
                  Fully Diluted Common Stock Outstanding (as hereinafter
                  defined). Net Income Before Taxes shall mean (i) the net
                  income of the Company and its consolidated subsidiaries
                  (determined on a consolidated basis for such periods in
                  accordance with generally accepted accounting principles
                  applied consistently with the Company's audited financial
                  statements), but excluding the effect of any extraordinary or
                  other material non-recurring gain (but not loss) outside the
                  ordinary course of business ("Consolidated Net Income"), plus
                  (ii) to


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                  the extent deducted in determining Consolidated Net Income
                  for such period, the amount of the provision for income taxes
                  for such period.

                  "FDEPS" means the fully diluted earnings per share with
                  respect to any fiscal year (which shall equal the Net Income
                  After Taxes (as defined herein) divided by the Fully Diluted
                  Common Stock Outstanding (as hereinafter defined). Net Income
                  After Taxes shall mean the net income of the Company and its
                  consolidated subsidiaries (determined on a consolidated basis
                  for such periods in accordance with generally accepted
                  accounting principles applied consistently with the Company's
                  audited financial statements), but excluding the effect of
                  any extraordinary or other material non-recurring gain (but
                  not loss) outside the ordinary course of business
                  ("Consolidated Net Income").

                  "Fully Diluted Common Stock Outstanding" means the number of
                  shares of the Company's voting common stock $.01 par value
                  and the Company's nonvoting common stock (collectively the
                  "Common Stock") which are issued and outstanding at the end
                  of the applicable fiscal year, plus those shares which would
                  be issued and outstanding upon the exercise or conversion of
                  all of the then outstanding options, warrants or other rights
                  to acquire any Common Stock or securities convertible into
                  Common Stock, or securities convertible into Common Stock of
                  the Company or securities or other instruments exchangeable
                  or convertible into Common Stock of the Company.

                  "Target FDEPS" means (i) for the fiscal year ending June 30,
                  1999 - $0.60 per share, (ii) for the fiscal year ending June
                  30, 2000 - $0.75 per share, and (iii)for the fiscal year
                  ending June 30, 2001 - $0.94 per share. For purposes of
                  determining the Target FDEPS for each of the fiscal years
                  ending June 30, 1997 and June 30, 1998, the Target EBT for
                  those years shall be divided by the Fully Diluted Common
                  Stock Outstanding at the end of the applicable fiscal year.
                  Notwithstanding the "Target FDEPS" amounts set forth above,
                  if at any time or from time to time after the date hereof the
                  Company or any of its subsidiaries acquires a business,
                  substantially all of the assets of a business, or any assets
                  material to the business of the Company or any of its
                  subsidiaries, the Board of Directors of the Company shall
                  make such adjustments to the "Target FDEPS" amounts, if any,
                  as the Board of Directors of the Company in its discretion
                  deems equitable in light of each such acquisition. Any such
                  determination by the Board of Directors shall be effective
                  and binding for all purposes of this Agreement and the Plan.

         4.       Section 13 is amended by adding at the end thereof a
                  subsection (c) as follows:

                  In the event that, after the date hereof, Fully Diluted
                  Common Stock Outstanding shall be increased or decreased or
                  changed into or exchanged for a different number or kind of
                  shares of stock or other securities of the Company or of
                  another corporation through reorganization, merger or
                  consolidation, recapitalization,


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                  reclassification, stock split, split-up, combination or
                  exchange of shares or declaration of any dividends payable in
                  Common Stock, the Board of Directors of the Company shall
                  appropriately adjust the Target FDEPS for each fiscal year
                  ending after said event to reflect the increase or decrease
                  in Fully Diluted Common Stock Outstanding such that the
                  Target FDEPS for that fiscal year will not be materially
                  affected by the increase or decrease.

         5.       As Nova Holdings, Inc. has formally changed its corporate
name to Accredo Health, Incorporated, the Agreement is hereby amended to
substitute throughout "Accredo Health, Incorporated" for "Nova Holdings, Inc."

         6.       This Agreement shall be governed by and construed in
accordance with the laws of the State of Tennessee. Employee specifically
acknowledges that Company has not made any representation or rendered any
advise concerning the tax effect of this Amendment. Employee acknowledges that
Employee has carefully read this Amendment and that Employee has consulted with
such legal, accounting and tax advisors as he or she deemed advisable with
regard to this Amendment. Employee acknowledges that Employee has signed this
Amendment as his or her own free act and has not been influenced in making this
agreement by any representation of the Company.

                              ACCREDO HEALTH, INCORPORATED

                              By:  /s/ Thomas W. Bell, Jr.
                                  ---------------------------------------------
                              Title:  Senior Vice President and General Counsel


                                /s/ Kyle Callahan
                              -------------------------------------------------
                              EMPLOYEE


Number of Shares of Common Stock
subject to the Agreement:    10,000
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Date of Grant:               02/09/98
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