$38,000.00 March 1, 2000
FOR VALUE RECEIVED, the undersigned promises to pay to Pain Therapeutics, Inc., a Delaware corporation
(the "COMPANY"), or order, the principal sum of Thirty-Eight Thousand Dollars ($38,000.00), together with
interest on the unpaid principal hereof from the date hereof at the rate of five and one-half percent (5.5%) per
annum, compounded annually.
Principal and interest shall be due and payable on January 31, 2004. Should the undersigned fail to make full
payment of principal or interest for a period of ten (10) days or more after the due date thereof, the whole unpaid
balance on this Note of principal and interest shall become immediately due at the option of the holder of this
Note. Payments of principal and interest shall be made in lawful money of the United States of America.
The undersigned may at any time prepay all or any portion of the principal or interest owing hereunder.
This Note is secured in part by a pledge of the Company's Common Stock under the terms of a Security
Agreement of even date herewith and is subject to all the provisions thereof.
The holder of this Note shall have full recourse against the undersigned, and shall not be required to proceed
against the collateral securing this Note in the event of default.
In the event the undersigned shall cease to be an employee or consultant of the Company for any reason, this
Note shall, at the option of the Company, be accelerated, and the whole unpaid balance on this Note of principal
and accrued interest shall be immediately due and payable.
Should any action be instituted for the collection of this Note, the reasonable costs and attorneys' fees therein of
the holder shall be paid by the undersigned.
DAVID L. JOHNSON
/s/ DAVID L. JOHNSON