Exhibit
10.44      March 6, 2003  VIA HAND DELIVERY  Charles K. Faas Pharsight Corporation  Dear Charlie:  As we have discussed with
you, Pharsight Corporation (the Company) in conjunction with Execustaff,
Inc., is pleased to offer you a promotion to the position of Chief Financial
Officer under the terms set forth in this letter.  Your promotion and the terms set forth in this letter agreement
(Agreement) shall be effective as of February 12, 2003.  Promotion and New Position  You will be promoted from
your current position of Vice President of Finance to the position of Chief
Financial Officer.  In your new
position, you will report to the Companys Chief Executive Officer (CEO).  Your areas of responsibility will include
management of the following departments: legal, human resources, accounting,
IT, QA management and public relations and any other tasks requested of you by
the CEO or the Companys Board of Directors (the Board).  Your office will continue to be located at
the Companys headquarters in Mountain View, California.  The Company continues to retain the
discretion to change your position, duties, reporting relationship and work
location, as it deems necessary.  Base Salary and Bonus Potential  As a result of your
promotion, your annual base salary will be increased to two hundred fifteen
thousand dollars ($215,000), subject to standard payroll deductions and
required withholdings, and paid on the Companys normal payroll schedule.  Pursuant to the terms and
conditions of the Companys Management Incentive Bonus Program for its
Executive Officers, you will be eligible to receive an annual performance bonus
of up to thirty-five percent (35%) of your previous and increased base
salaries, each on a pro rata basis, subject to standard payroll deductions and
required withholdings.  The Companys
Compensation Committee will determine in its sole discretion whether you have
earned an annual bonus, and the amount of any earned annual bonus.  The Company may modify
your compensation from time to time as it deems necessary.   1 
   Stock Options  Your current stock
options are not affected by your promotion or this Agreement, and your stock
option agreements will remain in full force and effect in accordance with their
terms.  Subject to Board approval, the
Company may grant you additional stock options at the next regularly scheduled
meeting in April 2003.  Employee Benefits  Your eligibility for
Company-sponsored employee benefits is not affected by your promotion or this
Agreement.  Proprietary Information and
Inventions Agreement; Company Policies and Procedures  Your Proprietary Information and Inventions Agreement with the Company
dated July 31, 2000 (the Proprietary Information Agreement) isnot affected by your promotion or this
Agreement, and the Proprietary Information Agreement will remain in full force
and effect in accordance with its terms. 
You will continue to be required to abide by the Proprietary Information
Agreement as a condition of your employment.  In addition, you will
continue to be required to abide by Pharsights policies and procedures, as may
be in effect from time to time.  At-Will Employment Relationship  Your employment continues
to be terminable at-will, and either you or the Company may terminate your
employment relationship at any time, with or without Cause (defined below) or
advance notice.  Severance Benefits In the event that your employment is involuntarily terminated by the
Company without Cause, as your sole severance benefits, for six (6) months
following the termination date, the Company will continue to pay your base
salary in effect on the termination date (the Severance Payments) and will
pay the costs to continue your health care coverage under COBRA at the same
level of coverage as in effect as of the termination date if you timely elect
continued health care coverage (collectively, the Severance Benefits).  As a condition of your receipt of the
Severance Benefits, you must first enter into a separation agreement with the
Company that includes your general release of all known and unknown claims, in
a form provided by the Company.  The
Severance Payments will be paid on the Companys normal payroll schedule and
will be subject to standard deductions and withholdings. For the purposes
of this letter, Cause for your termination shall mean:  (a) your conviction of any felony or of
any crime involving dishonesty; (b) your participation in any fraud or act
of dishonesty against the Company; (c) the material breach of your duties
to the Company, including persistent unsatisfactory performance of job duties;
(d) your intentional damage to, or willful misappropriation of, any
property of the Company; (e) your material breach of any written agreement with
the Company (including this Agreement or your Proprietary Information
Agreement); or (f) conduct, that in the good faith and reasonable determination
of the Board demonstrates gross unfitness to serve. In addition, if,
after a Change in Control (defined below), you resign from your employment with
the Company and such resignation qualifies as a Resignation for Good Reason
(defined below), you shall be entitled to receive the Severance Benefits, provided that you must first enter into a
separation agreement  2 
   with the Company
that includes your general release of all known and unknown claims, in a form
provided by the Company. For the purposes
of this letter, the occurrence of
either of the following events shall constitute a Change in Control:  (a) the sale or lease of all or
substantially all of the assets of the Company; or (b) an acquisition of the
Company by another corporation or entity by consolidation, merger or other reorganization
in each case in which the holders of the Companys outstanding voting stock
immediately prior to such transaction own, immediately after such transaction,
securities representing less than fifty percent (50%) of the voting power of
the corporation or other entity purchasing such assets or surviving such
transaction. For purposes of
this letter, a Resignation for Good Reason shall mean a resignation by you
due to any of the following events which occur after and as a direct result of
a Change in Control: (1) a material reduction in compensation, unless such
a reduction is applied, by resolution of the Board of Directors, to all members
of the Companys officers; (2) a material adverse change in your title due to a
demotion; or (3) a material adverse reduction in your role and responsibilities. You will not be
eligible for any severance benefits in the event of a termination with Cause or
any resignation that does not qualify as a Resignation for Good Reason. If the
relationship between Execustaff and the Company is terminated for any reason,
you will agree that the Company will become solely responsible as your
employer for all payroll, workers compensation and benefits, including
severance and vacation pay, and you will agree to seek the same only
from the Company. Miscellaneous  This Agreement sets forth
and forms the complete and exclusive statement of your employment agreement
with the Company concerning your promotion and employment terms, and this
Agreement supersedes any other agreements or promises made to you by anyone,
whether oral or written, concerning the subject matters set forth in this
letter including, but not limited to, your original offer letter with the
Company dated July 31, 2000 and your letter agreement with the Company dated
August 16, 2002.  This letter agreement cannot
be changed except in a writing signed by you and a duly authorized officer of
the Company.  We are very pleased to
offer you this promotion.  Please sign
and date this letter, and return it to me by March 7, 2003, if you wish to
accept this promotion under the terms described above.  Sincerely,Pharsight
  Corporation/s/  Shawn M. OConnorShawn M. OConnorPresident & Chief Executive OfficerACCEPTED:/s/ 
  Charles K. Faas
  
  March 7, 2003Charles K. Faas
  
  Date      3