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                   AMENDMENT TO LOAN AGREEMENT

     This Amendment To Loan Agreement (this "Amendment") is dated
as  of  April  30,  1999,  and entered into  by  and  between  CV
Therapeutics, Inc. ("Debtor"), a Delaware corporation, located at
3172  Porter  Drive,  Palo  Alto, California  94304  and  Biotech
Manufacturing  Ltd., a wholly-owned subsidiary  of  Biogen,  Inc.
("Secured  Party"), located at St. Paul's Gate, New  Street,  St.
Helier, Jersey JE48Z, Channel Islands.

                            Recitals

     A.    Debtor  and Secured Party are parties to that  certain
Loan Agreement dated as of March 7, 1997, as amended from time to
time  (the "Loan Agreement").  All capitalized terms used  herein
without definition shall have the meaning ascribed to them in the
Loan Agreement.

      B.    Under  the Loan Agreement, Debtor issued a Promissory
Note  dated  March  10, 1997, in favor of Secured  Party  in  the
amount of Twelve Million Dollars ($12,000,000) (the "Note").

     C.    Under  this  Amendment, the parties  desire  to  amend
certain provisions of the Loan Agreement and the Note as provided
below.

                            Agreement

     Now  Therefore, in consideration of the foregoing,  and  the
representations, warranties, and conditions set forth below,  the
parties  hereto, intending to be legally bound, hereby  agree  to
amend the Loan Agreement and Note as follows:

1.   Amendments.

     (a)  Section 2.1(b) of the Loan Agreement is hereby deleted in
its entirety and replaced with the following:

     "On the EFFECTIVE DATE CVT shall execute and deliver to
     BML unsecured note, substantially in the form set forth
     in  Appendix  A attached hereto and made a part  hereof
     (the   "Note"),  evidencing  the  Loan.    CVT   hereby
     covenants  not  to  incur  or maintain  any  additional
     senior  indebtedness while any amount  under  the  Note
     remains unpaid.  The Note shall be subordinated to  all
     debt  of  CVT existing as of March 7, 1999 and  may  be
     prepaid by CVT at any time without penalty, in cash or,
     in  case  of  the Loan Remainder, in CVT Common  Stock,
     registered  for resale, priced at its then Fair  Market
     Value (as defined in Section 2.1(i) below), subject  to
     the  provisions  of subsections (g)  and  (i)  of  this
     Section 2.1."

     (b)  The first sentence of Section 2.1(c) of the Loan Agreement
is   hereby  deleted  in  its  entirety  and  replaced  with  the
following:

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          "The  Note  shall bear interest on the outstanding
          principal amount thereof at a rate per annum equal
          to  Prime (as defined below) plus one and one half
          percent (1.5%)."

     (c)  The following is added to the end of Section 5.1 of the Loan
Agreement:

     "Notwithstanding   the   foregoing,   all   of    CVT's
     representations, warranties and covenants contained  in
     this Agreement shall terminate upon the termination  or
     expiration of this Agreement.  The covenants set  forth
     in   Section   2.1(b)  shall  survive  termination   or
     expiration  of  this Agreement until  all  amounts  due
     under the Note have been repaid in full."

     (d)  The first sentence under the "Interest" section of the Note
shall be deleted and replaced with the following:

          "Interest   shall   accrue  on   the   outstanding
          principal  balance hereunder at a rate  per  annum
          equal to Prime plus 1.5%."


     (e)  Section (j) under the "Event of Default" section of the Note
shall be deleted in its entirety and replaced with the following:

     There   occurs  a  Change  of  Control  with  Borrower.
     "Change of Control" shall mean the occurrence of any of
     the  following  events:  (i) the  acquisition,  whether
     directly  or  indirectly,  by  any  person  or  entity,
     including  a "group" as defined in Section 13(d)(3)  of
     the  Exchange Act, of more than forty percent (40%)  of
     the Common Stock of Borrower; (ii) Borrower shall merge
     or  consolidate  with or into another corporation  with
     the  effect  that the persons who were the shareholders
     of  Borrower immediately prior to the effective time of
     such  merger or consolidation hold less than  fifty-one
     percent  (51%)  of  the combined voting  power  of  the
     outstanding securities of the surviving corporation  of
     such  merger  or  the corporation resulting  from  such
     consolidation   ordinarily  (and  apart   from   rights
     accruing under special circumstances) having the  right
     to  vote in the election of directors; or (iii) at  any
     time  during any calendar year, fifty percent (50%)  or
     more  of the members of the full Board of Directors  of
     Borrower  shall  have  resigned  or  been  removed   or
     replaced.

2.   Miscellaneous.

     (a)  Waivers and Amendments.  Any provision of this Amendment may
be  amended, waived or modified only upon the written consent  of
Debtor and Secured Party.

     (b)  Governing Law.  This Amendment and all actions arising out
of  or in connection with this Amendment shall be governed by and
construed  in accordance with the laws of the State of  Delaware,
without regard to the conflicts of law provisions of the State of
Delaware or of any other state.

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     (c)  Successors and Assigns. The rights and obligations of Debtor
and Secured Party shall be binding upon and benefit the
successors, assigns, heirs, administrators and transferees of the
parties.

     (d)  Entire Agreement.  This Amendment together with the Loan
Agreement, the BML Agreement, the Biogen Agreement, the Stock
Purchase Agreement and the Note, constitute the full and entire
understanding and agreement between the parties with regard to
the subjects hereof and thereof.

     (e)  Severability of this Agreement.  If any provision of this
Amendment shall be judicially determined to be invalid, illegal
or unenforceable, the validity, legality and enforceability of
the remaining provisions shall not in any way be affected or
impaired thereby.

     (f)  Counterparts.  This Amendment may be executed in any number
of  counterparts, each of which shall be an original, but all  of
which together shall be deemed to constitute one instrument.







BIOTECH MANUFACTURING LTD.         CV THERAPEUTICS, INC.

By    /s/ Timothy M. Kish                By    /s/ Louis Lange

Name  Timothy M. Kish                    Name  Louis G. Lange

Title Director                           Title Chairman & CEO