<PAGE>
                   FIRST AMENDMENT TO BUSINESS LOAN AGREEMENT


     THIS FIRST AMENDMENT TO BUSINESS LOAN AGREEMENT ("Amendment") is entered 
into as of March 7th, 1997, by and among Hambrecht & Quist Transition 
Capital, LLC ("H&QTC"), a California limited liability company, and CV 
Therapeutics, Inc., a Delaware corporation ("CVT").

                                    RECITALS

     A. H&QTC and CVT are parties to that certain Business Loan Agreement, 
dated as of September 27, 1996 (the "H&QTC Loan Agreement") and certain 
Related Documents (as defined in the H&QTC Loan Agreement).

     B. CVT intends to enter into certain transactions (the "Collaboration") 
contemplated by (i) a Research Collaboration and License Agreement 
substantially in the form attached hereto as Exhibit A; (ii) a Loan Agreement 
and Promissory Note substantially in the form attached hereto as Exhibits B 
and C, respectively; (iii) a Common Stock Purchase Agreement substantially in 
the form attached hereto as exhibit D; and (iv) any related documents 
provided for by any of the foregoing ((i) through (iv), collectively, the 
"Collaboration Agreement").

     NOW, THEREFORE, in consideration of the foregoing recitals and other 
good and valuable consideration, the receipt and adequacy of which is hereby 
acknowledged, and intending to be legally bound, the parties hereby agree to 
amend the H&QTC Loan Agreement only as follows:

     THEREFORE, the Business Loan Agreement is amended only as follows:

1.   The following definition will be added to Section 1 of the Business Loan 
Agreement:

     "PERMITTED UNSECURED INDEBTEDNESS" shall mean and include all 
Indebtedness from Borrower to Biotech Manufacturing Ltd., a wholly owned 
subsidiary of Biogen, Inc. under that certain Loan Agreement dated as of 
March 10, 1997.

2.   The definition of Related Documents is struck in its entirety, and the 
following definition substituted therefor:

          "RELATED DOCUMENTS" means and includes without limitation the 
          PROMISSORY NOTE, the Security Agreement, all other promissory 
          notes, credit agreements, loan agreements, guaranties, security 
          agreements, mortgages, deeds of trust, and all other instruments 
          and documents, whether now or hereafter existing, executed in 
          connection with any of the foregoing and agreements between Debtor 
          and Hambrecht & Quist Guaranty Finance, LLC ("H&QGF") including 
          without limitation the Master Lease Agreement, Equipment 
          Schedules, and the Security Agreement.

3.   Section 5.1 is struck in its entirety, and the following is substituted 
therefor:

<PAGE>

          Section 5.1    INDEBTEDNESS AND LIENS

          (a) incur, assume or permit to exist any Indebtedness other than 
     (i) Permitted Senior Indebtedness, (ii) accounts payable to trade 
     creditors for goods and services and current operating liabilities (not 
     the result of the borrowing of money) incurred in the ordinary course 
     of Borrower's business in accordance with customary terms and that are 
     not delinquent, and (iii) Indebtedness of Borrower secured by liens 
     permitted pursuant to clause (b)(ii) of this Section 5.1; (iv) 
     Indebtedness existing on the date hereof and disclosed in Exhibit A 
     hereto, (v) contingent obligations of Borrower consisting of guarantees 
     (and other credit support) of the obligations of vendors and suppliers 
     of Borrower in respect of transactions entered into in the ordinary 
     course of business, (vi) other Indebtedness of Borrower, provided that 
     the total amount in the aggregate outstanding INDEBTEDNESS at any time 
     described in (iv), (v), and (vi) above not to exceed $250,000; (vii) 
     Permitted Unsecured Indebtedness, and (viii) extensions, renewals, 
     refundings, refinancings, modifications, amendments and restatements of 
     any of the items of Indebtedness described in (i) through (vii) above, 
     PROVIDED that the principal amount thereof is not increased or the 
     terms thereof are not modified to impose more burdensome terms upon 
     Borrower, (b) except as otherwise permitted herein, or in any Related 
     Document, create, incur, or assume any mortgage, pledge encumbrance, 
     lien or charge of any kind (including the charge upon property at any 
     time purchased or acquired under conditional sale or other property at 
     any time purchased or acquired under conditional sale or other title 
     retention agreement) upon any asset now owned or hereafter acquired, 
     except for (i) SECURITY INTEREST that are granted in favor of the 
     SENIOR LENDER as security for the PERMITTED SENIOR INDEBTEDNESS, (ii) 
     other than as permitted pursuant to clause  (iii) hereof, SECURITY 
     INTERESTS that are to secure Borrower's Indebtedness incurred solely 
     for the purpose of financing the acquisition or lease of any specific 
     items of equipment and granted in favor of a purchase money lender or 
     equipment lessor with respect to such Indebtedness, but only to the 
     extent that such lien is confined solely to the equipment so acquired 
     and such INDEBTEDNESS is limited to the purchase price or lease 
     obligations the respect to such equipment, and (iii) easements, 
     reservations, rights of way, restrictions, minor defects or 
     irregularities in title and other similar liens, (iv) liens in favor of 
     customers and revenue authorities arising as a matter of law to secure 
     payments of customs duties in connection with the importation of goods; 
     (v) liens arising solely by virtue of any statutory or common law 
     provision relating to banker's liens, rights of setoff or similar 
     rights and remedies as to deposit accounts or other funds maintained 
     with a creditor depository institution; (vi) liens existing on the date 
     hereof and disclosed on Exhibit A hereto; (vii) liens not otherwise 
     permitted, which liens do not in the aggregate exceed $250,000 at any 
     time (ix) liens incurred in connection with the extension, renewal or 
     refinancing of the indebtedness secured by liens of the type described 
     in clauses (i) through (ii) above, provided that any extension, renewal 
     or replacement lien  shall be limited to the property encumbered by the 
     existing lien and the principal amount of the indebtedness being 
     extended, renewed or refinanced does not increase.

4.   Except as specifically amended hereby, the Business Loan Agreement shall 
remain in full force and effect.

<PAGE>

     IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be 
executed by their respective officers thereunto duly authorized, as of the 
date first above written.



CVT:                                   CV Therapeutics, Inc.
                                       a Delaware corporation


                                       By: /s/ Louis Lange
                                          ------------------------------
                                       Printed Name: L. Lange
                                                    --------------------
                                       Title: CEO
                                             ---------------------------


H&QTC:                                 Hambrecht & Quist Transition Capital, LLC
                                       a California limited liability company


                                       By: /s/ Andrew W. Kahn
                                          ------------------------------
                                       Printed Name: Andrew W. Kahn
                                                    --------------------
                                       Title: Chief Executive Officer
                                             ---------------------------