<PAGE>

                                                                 EXHIBIT 10.40.1

                             CHOLESTECH CORPORATION

                               FIRST AMENDMENT TO
                   AMENDED AND RESTATED SEVERANCE ARRANGEMENT

         This First Amendment to the Amended and Restated Severance Agreement
dated as of June 14, 2001 (the "Agreement"), is made as of March 27, 2003 (the
"Amendment"), by and between Cholestech Corporation, a California corporation
(the "Company"), and Warren E. Pinckert II (the "Executive").

         WHEREAS, the Company and the Executive desire to amend Section 2 and
Section 3 of the Agreement;

         NOW, THEREFORE, in consideration of the foregoing and the mutual
promises set forth herein, the Company and the Executive agree as follows:

         1.  Section 2 is hereby amended to read in its entirety as
follows:

        "2.  Severance Benefits.

                  (a)      Option Acceleration. If the Company terminates the
Executive's employment, for any or no reason, then any unvested and outstanding
stock options granted to the Executive by the Company shall accelerate as to
that number of shares which would have become vested and exercisable had the
Executive remained employed with the Company until the date that is 18 months
after the date of such termination. Such accelerated shares shall continue to be
subject to the terms and conditions of the Company's stock option plans and the
applicable option agreements between the Executive and the Company. The
Executive agrees and acknowledges that the remaining unvested shares of the
Company subject to his stock options, excluding the accelerated shares
referenced above, shall terminate immediately as of the date of such
termination.

                  (b)      Severance Payment. If the Company terminates the
Executive's employment, for any or no reason, then the Executive shall be
entitled to receive a severance payment in an amount equal to 18 months of the
Executive's base salary as in effect immediately prior to such termination. Such
severance payment shall be in lieu of any other severance payment to which the
Executive shall be entitled pursuant to any employment agreement, other letter
or the Company's then existing severance plans and policies; provided, however,
that the Executive shall be entitled to the severance payment provided for in
Section 4(b)(i) of the Change of Control Severance Agreement between the
Executive and the Company (the "Change of Control Agreement") in lieu of the
severance payment provided for under this Agreement if the Executive's
employment with the Company terminates as a result of an Involuntary Termination
(as such term is defined in the Change of Control Agreement) at any time within
12 months after a Change of Control (as such term is defined in the Change of
Control Agreement). Such severance payment shall be payable over a period of 18
months commencing on the date of such termination in accordance with the
Company's normal payment practices. In addition, during the 18 month period
commencing on the date of such termination, the Company shall continue to make
available to the Executive and the Executive's spouse and dependents covered
under any group health plans or life insurance plans of the Company on the date
of such termination of employment, all group health, life and other similar
insurance
<PAGE>
plans in which the Executive or such covered dependents participate on the date
of the Executive's termination; provided, however, that (i) the Executive
constitutes a qualified beneficiary, as defined in Section 4980B(g)(1) of the
Internal Revenue Code of 1986, as amended; and (ii) the Executive elects
continuation coverage pursuant to the Consolidated Omnibus Budget Reconciliation
Act of 1985, as amended ("COBRA"), within the time period prescribed pursuant to
COBRA."

         2.  Section 3 is hereby amended to read in its entirety as
follows:

        "3.  Mitigation. The Executive shall not be required to mitigate
the amount of any payment contemplated by this Agreement, nor shall any such
payment be reduced by any earnings that the Executive may receive from any other
source. However, the Executive shall not be entitled to receive the health
coverage and benefits contemplated by this Agreement in the event that the
Executive receives similar health coverage and benefits as a result of new
employment during the 18 month period commencing on the date of the Executive's
termination."

         3.  Except as amended as set forth above, the Agreement shall
continue in full force and effect and the parties thereto shall continue to
enjoy and be bound by all of their rights and obligations thereunder.

         4.  This Amendment shall be governed by and construed in
accordance with the laws of the State of California, regardless of the laws that
might otherwise govern under applicable principles of conflicts of laws thereof.

         5.  This Amendment may be executed in one or more counterparts,
all of which shall be considered one and the same amendment, and shall become
effective when one or more counterparts have been signed by each of the parties
and delivered to the other party, it being understood that all parties need not
sign the same counterpart.

         6.  Capitalized terms not otherwise defined in this Amendment
shall have the meanings ascribed to them in the Agreement.

                  [REMAINDER OF PAGE LEFT BLANK INTENTIONALLY]



                                                                             -2-
<PAGE>
         IN WITNESS WHEREOF, the parties hereto have executed this First
Amendment to the Amended and Restated Severance Agreement as of the day and year
first above written.

                                    CHOLESTECH CORPORATION
                                    a California corporation



                                    By:    /s/ John H. Landon
                                           ------------------------------------
                                           John H. Landon
                                           Chairman of the Board of Directors



                                    /s/ Warren E. Pinckert II
                                    -------------------------------------------
                                    Warren E. Pinckert II




                                                                             -3-