Exhibit 10.5

NITROMED, INC.

2003 EMPLOYEE STOCK PURCHASE PLAN

The purpose of this Plan is to provide eligible employees of NitroMed, Inc. (the
“Company”) and certain of its subsidiaries with opportunities to purchase shares
of the Company’s common stock, $0.01 par value (the “Common Stock”), commencing
on January 1, 2004.  Seventy Five Thousand (75,000) shares of Common Stock in
the aggregate have been approved for this purpose.  This Plan is intended to
qualify as an “employee stock purchase plan” as defined in Section 423 of the
Internal Revenue Code of 1986, as amended (the “Code”), and the regulations
promulgated thereunder, and shall be interpreted consistent therewith.

1.                                       ADMINISTRATION.  THE PLAN WILL BE
ADMINISTERED BY THE COMPANY’S BOARD OF DIRECTORS (THE “BOARD”) OR BY A COMMITTEE
APPOINTED BY THE BOARD (THE “COMMITTEE”).  THE BOARD OR THE COMMITTEE HAS
AUTHORITY TO MAKE RULES AND REGULATIONS FOR THE ADMINISTRATION OF THE PLAN AND
ITS INTERPRETATION AND DECISIONS WITH REGARD THERETO SHALL BE FINAL AND
CONCLUSIVE.

2.                                       ELIGIBILITY.  ALL EMPLOYEES OF THE
COMPANY, INCLUDING DIRECTORS WHO ARE EMPLOYEES, AND ALL EMPLOYEES OF ANY
SUBSIDIARY OF THE COMPANY (AS DEFINED IN SECTION 424(F) OF THE CODE) DESIGNATED
BY THE BOARD OR THE COMMITTEE FROM TIME TO TIME (A “DESIGNATED SUBSIDIARY”), ARE
ELIGIBLE TO PARTICIPATE IN ANY ONE OR MORE OF THE OFFERINGS OF OPTIONS (AS
DEFINED IN SECTION 9) TO PURCHASE COMMON STOCK UNDER THE PLAN PROVIDED THAT:

(A)                                  THEY ARE CUSTOMARILY EMPLOYED BY THE
COMPANY OR A DESIGNATED SUBSIDIARY FOR MORE THAN 20 HOURS A WEEK AND FOR MORE
THAN FIVE MONTHS IN A CALENDAR YEAR; AND

(B)                                 THEY HAVE BEEN EMPLOYED BY THE COMPANY OR A
DESIGNATED SUBSIDIARY FOR AT LEAST SIX MONTHS PRIOR TO ENROLLING IN THE PLAN;
AND

(C)                                  THEY ARE EMPLOYEES OF THE COMPANY OR A
DESIGNATED SUBSIDIARY ON THE FIRST DAY OF THE APPLICABLE PLAN PERIOD (AS DEFINED
BELOW).

No employee may be granted an option hereunder if such employee, immediately
after the option is granted, owns 5% or more of the total combined voting power
or value of the stock of the Company or any subsidiary.  For purposes of the
preceding sentence, the attribution rules of Section 424(d) of the Code shall
apply in determining the stock ownership of an employee, and all stock which the
employee has a contractual right to purchase shall be treated as stock owned by
the employee.

3.                                       OFFERINGS.  THE COMPANY WILL MAKE ONE
OR MORE OFFERINGS (“OFFERINGS”) TO EMPLOYEES TO PURCHASE STOCK UNDER THIS PLAN. 
OFFERINGS WILL BEGIN EACH JANUARY 1 AND JULY 1, OR THE FIRST BUSINESS DAY
THEREAFTER (THE “OFFERING COMMENCEMENT DATES”).  EACH OFFERING COMMENCEMENT DATE
WILL BEGIN A SIX MONTH PERIOD (A “PLAN PERIOD”) DURING WHICH PAYROLL DEDUCTIONS
WILL BE MADE AND HELD FOR THE PURCHASE OF COMMON STOCK AT THE END OF THE PLAN
PERIOD.  THE BOARD OR THE COMMITTEE MAY, AT ITS DISCRETION, CHOOSE A DIFFERENT
PLAN PERIOD OF TWELVE (12) MONTHS OR LESS FOR SUBSEQUENT OFFERINGS.

4.                                       PARTICIPATION.  AN EMPLOYEE ELIGIBLE ON
THE OFFERING COMMENCEMENT DATE OF ANY OFFERING MAY PARTICIPATE IN SUCH OFFERING
BY COMPLETING AND FORWARDING A PAYROLL DEDUCTION AUTHORIZATION FORM TO THE
EMPLOYEE’S APPROPRIATE PAYROLL OFFICE AT LEAST TEN DAYS PRIOR TO THE APPLICABLE
OFFERING COMMENCEMENT DATE.  THE FORM WILL AUTHORIZE A REGULAR PAYROLL DEDUCTION
FROM THE

--------------------------------------------------------------------------------

COMPENSATION RECEIVED BY THE EMPLOYEE DURING THE PLAN PERIOD.  UNLESS AN
EMPLOYEE FILES A NEW FORM OR WITHDRAWS FROM THE PLAN, HIS DEDUCTIONS AND
PURCHASES WILL CONTINUE AT THE SAME RATE FOR FUTURE OFFERINGS UNDER THE PLAN AS
LONG AS THE PLAN REMAINS IN EFFECT.  THE TERM “COMPENSATION” MEANS THE AMOUNT OF
MONEY REPORTABLE ON THE EMPLOYEE’S FEDERAL INCOME TAX WITHHOLDING STATEMENT,
EXCLUDING OVERTIME, SHIFT PREMIUM, INCENTIVE OR BONUS AWARDS, ALLOWANCES AND
REIMBURSEMENTS FOR EXPENSES SUCH AS RELOCATION ALLOWANCES FOR TRAVEL EXPENSES,
INCOME OR GAINS ON THE EXERCISE OF COMPANY STOCK OPTIONS OR STOCK APPRECIATION
RIGHTS, AND SIMILAR ITEMS, WHETHER OR NOT SHOWN ON THE EMPLOYEE’S FEDERAL INCOME
TAX WITHHOLDING STATEMENT, BUT INCLUDING, IN THE CASE OF SALESPERSONS, SALES
COMMISSIONS TO THE EXTENT DETERMINED BY THE BOARD OR THE COMMITTEE.

5.             DEDUCTIONS.  THE COMPANY WILL MAINTAIN PAYROLL DEDUCTION ACCOUNTS
FOR ALL PARTICIPATING EMPLOYEES.  WITH RESPECT TO ANY OFFERING MADE UNDER THIS
PLAN, AN EMPLOYEE MAY AUTHORIZE A PAYROLL DEDUCTION IN ANY DOLLAR AMOUNT UP TO A
MAXIMUM OF 10% OF THE COMPENSATION HE OR SHE RECEIVES DURING THE PLAN PERIOD OR
SUCH SHORTER PERIOD DURING WHICH DEDUCTIONS FROM PAYROLL ARE MADE.  PAYROLL
DEDUCTIONS MAY BE AT THE RATE OF 2%, 4%, 6%, 8% OR 10% OF COMPENSATION WITH ANY
CHANGE IN COMPENSATION DURING THE PLAN PERIOD TO RESULT IN AN AUTOMATIC
CORRESPONDING CHANGE IN THE DOLLAR AMOUNT WITHHELD.

6.             DEDUCTION CHANGES.  AN EMPLOYEE MAY DECREASE OR DISCONTINUE HIS
PAYROLL DEDUCTION ONCE DURING ANY PLAN PERIOD, BY FILING A NEW PAYROLL DEDUCTION
AUTHORIZATION FORM.  HOWEVER, AN EMPLOYEE MAY NOT INCREASE HIS PAYROLL DEDUCTION
DURING A PLAN PERIOD.  IF AN EMPLOYEE ELECTS TO DISCONTINUE HIS PAYROLL
DEDUCTIONS DURING A PLAN PERIOD, BUT DOES NOT ELECT TO WITHDRAW HIS FUNDS
PURSUANT TO SECTION 8 HEREOF, FUNDS DEDUCTED PRIOR TO HIS ELECTION TO
DISCONTINUE WILL BE APPLIED TO THE PURCHASE OF COMMON STOCK ON THE EXERCISE DATE
(AS DEFINED BELOW).

7.             INTEREST.  INTEREST WILL NOT BE PAID ON ANY EMPLOYEE ACCOUNTS,
EXCEPT TO THE EXTENT THAT THE BOARD OR THE COMMITTEE, IN ITS SOLE DISCRETION,
ELECTS TO CREDIT EMPLOYEE ACCOUNTS WITH INTEREST AT SUCH PER ANNUM RATE AS IT
MAY FROM TIME TO TIME DETERMINE.

8.             WITHDRAWAL OF FUNDS.  AN EMPLOYEE MAY AT ANY TIME PRIOR TO THE
CLOSE OF BUSINESS ON THE LAST BUSINESS DAY IN A PLAN PERIOD AND FOR ANY REASON
PERMANENTLY DRAW OUT THE BALANCE ACCUMULATED IN THE EMPLOYEE’S ACCOUNT AND
THEREBY WITHDRAW FROM PARTICIPATION IN AN OFFERING.  PARTIAL WITHDRAWALS ARE NOT
PERMITTED.  THE EMPLOYEE MAY NOT BEGIN PARTICIPATION AGAIN DURING THE REMAINDER
OF THE PLAN PERIOD.  THE EMPLOYEE MAY PARTICIPATE IN ANY SUBSEQUENT OFFERING IN
ACCORDANCE WITH TERMS AND CONDITIONS ESTABLISHED BY THE BOARD OR THE COMMITTEE.

9.             PURCHASE OF SHARES.  ON THE OFFERING COMMENCEMENT DATE OF EACH
PLAN PERIOD, THE COMPANY WILL GRANT TO EACH ELIGIBLE EMPLOYEE WHO IS THEN A
PARTICIPANT IN THE PLAN AN OPTION (“OPTION”) TO PURCHASE ON THE LAST BUSINESS
DAY OF SUCH PLAN PERIOD (THE “EXERCISE DATE”), AT THE OPTION PRICE HEREINAFTER
PROVIDED FOR, THE LARGEST NUMBER OF WHOLE SHARES OF COMMON STOCK OF THE COMPANY
AS DOES NOT EXCEED THE NUMBER OF SHARES DETERMINED BY MULTIPLYING $2,083 BY THE
NUMBER OF FULL MONTHS IN THE OFFERING PERIOD AND DIVIDING THE RESULT BY THE
CLOSING PRICE (AS DEFINED BELOW) ON THE OFFERING COMMENCEMENT DATE OF SUCH PLAN
PERIOD.

Notwithstanding the above, no employee may be granted an Option (as defined in
Section 9) which permits his rights to purchase Common Stock under this Plan and
any other employee stock purchase plan (as defined in Section 423(b) of the
Code) of the Company and its subsidiaries, to accrue at a rate which exceeds
$25,000 of the fair market value of such Common Stock (determined at the
Offering Commencement Date of the Plan Period) for each calendar year in which
the Option is outstanding at any time.

2

--------------------------------------------------------------------------------

The purchase price for each share purchased will be 85% of the closing price of
the Common Stock on (i) the first business day of such Plan Period or (ii) the
Exercise Date, whichever closing price shall be less.  Such closing price shall
be (a) the closing price on any national securities exchange on which the Common
Stock is listed, (b) the closing price of the Common Stock on the Nasdaq
National Market or (c) the average of the closing bid and asked prices in the
over-the-counter-market, whichever is applicable, as published in The Wall
Street Journal.  If no sales of Common Stock were made on such a day, the price
of the Common Stock for purposes of clauses (a) and (b) above shall be the
reported price for the next preceding day on which sales were made.

Each employee who continues to be a participant in the Plan on the Exercise Date
shall be deemed to have exercised his Option at the Option Price on such date
and shall be deemed to have purchased from the Company the number of full shares
of Common Stock reserved for the purpose of the Plan that his accumulated
payroll deductions on such date will pay for, but not in excess of the maximum
number determined in the manner set forth above.

Any balance remaining in an employee’s payroll deduction account at the end of a
Plan Period will be automatically refunded to the employee, except that any
balance which is less than the purchase price of one share of Common Stock will
be carried forward into the employee’s payroll deduction account for the
following Offering, unless the employee elects not to participate in the
following Offering under the Plan, in which case the balance in the employee’s
account shall be refunded.

10.           ISSUANCE OF CERTIFICATES.  CERTIFICATES REPRESENTING SHARES OF
COMMON STOCK PURCHASED UNDER THE PLAN MAY BE ISSUED ONLY IN THE NAME OF THE
EMPLOYEE, IN THE NAME OF THE EMPLOYEE AND ANOTHER PERSON OF LEGAL AGE AS JOINT
TENANTS WITH RIGHTS OF SURVIVORSHIP, OR (IN THE COMPANY’S SOLE DISCRETION) IN
THE NAME OF A BROKERAGE FIRM, BANK OR OTHER NOMINEE HOLDER DESIGNATED BY THE
EMPLOYEE.  THE COMPANY MAY, IN ITS SOLE DISCRETION AND IN COMPLIANCE WITH
APPLICABLE LAWS, AUTHORIZE THE USE OF BOOK ENTRY REGISTRATION OF SHARES IN LIEU
OF ISSUING STOCK CERTIFICATES.

11.           RIGHTS ON RETIREMENT, DEATH OR TERMINATION OF EMPLOYMENT.  IN THE
EVENT OF A PARTICIPATING EMPLOYEE’S TERMINATION OF EMPLOYMENT PRIOR TO THE LAST
BUSINESS DAY OF A PLAN PERIOD, NO PAYROLL DEDUCTION SHALL BE TAKEN FROM ANY PAY
DUE AND OWING TO AN EMPLOYEE AND THE BALANCE IN THE EMPLOYEE’S ACCOUNT SHALL BE
PAID TO THE EMPLOYEE OR, IN THE EVENT OF THE EMPLOYEE’S DEATH, (A) TO A
BENEFICIARY PREVIOUSLY DESIGNATED IN A REVOCABLE NOTICE SIGNED BY THE EMPLOYEE
(WITH ANY SPOUSAL CONSENT REQUIRED UNDER STATE LAW) OR (B) IN THE ABSENCE OF
SUCH A DESIGNATED BENEFICIARY, TO THE EXECUTOR OR ADMINISTRATOR OF THE
EMPLOYEE’S ESTATE OR (C) IF NO SUCH EXECUTOR OR ADMINISTRATOR HAS BEEN APPOINTED
TO THE KNOWLEDGE OF THE COMPANY, TO SUCH OTHER PERSON(S) AS THE COMPANY MAY, IN
ITS DISCRETION, DESIGNATE.  IF, PRIOR TO THE LAST BUSINESS DAY OF THE PLAN
PERIOD, THE DESIGNATED SUBSIDIARY BY WHICH AN EMPLOYEE IS EMPLOYED SHALL CEASE
TO BE A SUBSIDIARY OF THE COMPANY, OR IF THE EMPLOYEE IS TRANSFERRED TO
A SUBSIDIARY OF THE COMPANY THAT IS NOT A DESIGNATED SUBSIDIARY, THE EMPLOYEE
SHALL BE DEEMED TO HAVE TERMINATED EMPLOYMENT FOR THE PURPOSES OF THIS PLAN.

12.           OPTIONEES NOT STOCKHOLDERS.  NEITHER THE GRANTING OF AN OPTION TO
AN EMPLOYEE NOR THE DEDUCTIONS FROM HIS PAY SHALL CONSTITUTE SUCH EMPLOYEE A
STOCKHOLDER OF THE SHARES OF COMMON STOCK COVERED BY AN OPTION UNDER THIS PLAN
UNTIL SUCH SHARES HAVE BEEN PURCHASED BY AND ISSUED TO HIM.

13.           RIGHTS NOT TRANSFERABLE.  RIGHTS UNDER THIS PLAN ARE NOT
TRANSFERABLE BY A PARTICIPATING EMPLOYEE OTHER THAN BY WILL OR THE LAWS OF
DESCENT AND DISTRIBUTION, AND ARE EXERCISABLE DURING THE EMPLOYEE’S LIFETIME
ONLY BY THE EMPLOYEE.

14.           APPLICATION OF FUNDS.  ALL FUNDS RECEIVED OR HELD BY THE COMPANY
UNDER THIS PLAN MAY BE COMBINED WITH OTHER CORPORATE FUNDS AND MAY BE USED FOR
ANY CORPORATE PURPOSE.

3

--------------------------------------------------------------------------------

15.           ADJUSTMENT IN CASE OF CHANGES AFFECTING COMMON STOCK.  IN THE
EVENT OF A SUBDIVISION OF OUTSTANDING SHARES OF COMMON STOCK, OR THE PAYMENT OF
A DIVIDEND IN COMMON STOCK, THE NUMBER OF SHARES APPROVED FOR THIS PLAN, AND THE
SHARE LIMITATION SET FORTH IN SECTION 9, SHALL BE INCREASED PROPORTIONATELY, AND
SUCH OTHER ADJUSTMENT SHALL BE MADE AS MAY BE DEEMED EQUITABLE BY THE BOARD OR
THE COMMITTEE.  IN THE EVENT OF ANY OTHER CHANGE AFFECTING THE COMMON STOCK,
SUCH ADJUSTMENT SHALL BE MADE AS MAY BE DEEMED EQUITABLE BY THE BOARD OR THE
COMMITTEE TO GIVE PROPER EFFECT TO SUCH EVENT.

16.           MERGER.  IF THE COMPANY SHALL AT ANY TIME MERGE OR CONSOLIDATE
WITH ANOTHER CORPORATION AND THE HOLDERS OF THE CAPITAL STOCK OF THE COMPANY
IMMEDIATELY PRIOR TO SUCH MERGER OR CONSOLIDATION CONTINUE TO HOLD AT LEAST 80%
BY VOTING POWER OF THE CAPITAL STOCK OF THE SURVIVING CORPORATION (“CONTINUITY
OF CONTROL”), THE HOLDER OF EACH OPTION THEN OUTSTANDING WILL THEREAFTER BE
ENTITLED TO RECEIVE AT THE NEXT EXERCISE DATE UPON THE EXERCISE OF SUCH OPTION
FOR EACH SHARE AS TO WHICH SUCH OPTION SHALL BE EXERCISED THE SECURITIES OR
PROPERTY WHICH A HOLDER OF ONE SHARE OF THE COMMON STOCK WAS ENTITLED TO UPON
AND AT THE TIME OF SUCH MERGER OR CONSOLIDATION, AND THE BOARD OR THE COMMITTEE
SHALL TAKE SUCH STEPS IN CONNECTION WITH SUCH MERGER OR CONSOLIDATION AS THE
BOARD OR THE COMMITTEE SHALL DEEM NECESSARY TO ASSURE THAT THE PROVISIONS OF
SECTION 15 SHALL THEREAFTER BE APPLICABLE, AS NEARLY AS REASONABLY MAY BE, IN
RELATION TO THE SAID SECURITIES OR PROPERTY AS TO WHICH SUCH HOLDER OF SUCH
OPTION MIGHT THEREAFTER BE ENTITLED TO RECEIVE THEREUNDER.

In the event of a merger or consolidation of the Company with or into another
corporation which does not involve Continuity of Control, or of a sale of all or
substantially all of the assets of the Company while unexercised Options remain
outstanding under the Plan, (a) subject to the provisions of clauses (b) and
(c), after the effective date of such transaction, each holder of an outstanding
Option shall be entitled, upon exercise of such Option, to receive in lieu of
shares of Common Stock, shares of such stock or other securities as the holders
of shares of Common Stock received pursuant to the terms of such transaction; or
(b) all outstanding Options may be cancelled by the Board or the Committee as of
a date prior to the effective date of any such transaction and all payroll
deductions shall be paid out to the participating employees; or (c) all
outstanding Options may be cancelled by the Board or the Committee as of the
effective date of any such transaction, provided that notice of such
cancellation shall be given to each holder of an Option, and each holder of an
Option shall have the right to exercise such Option in full based on payroll
deductions then credited to his account as of a date determined by the Board or
the Committee, which date shall not be less than ten (10) days preceding the
effective date of such transaction.

17.           AMENDMENT OF THE PLAN.  THE BOARD MAY AT ANY TIME, AND FROM TIME
TO TIME, AMEND THIS PLAN IN ANY RESPECT, EXCEPT THAT (A) IF THE APPROVAL OF ANY
SUCH AMENDMENT BY THE SHAREHOLDERS OF THE COMPANY IS REQUIRED BY SECTION 423 OF
THE CODE, SUCH AMENDMENT SHALL NOT BE EFFECTED WITHOUT SUCH APPROVAL, AND (B) IN
NO EVENT MAY ANY AMENDMENT BE MADE WHICH WOULD CAUSE THE PLAN TO FAIL TO COMPLY
WITH SECTION 423 OF THE CODE.

18.           INSUFFICIENT SHARES.  IN THE EVENT THAT THE TOTAL NUMBER OF SHARES
OF COMMON STOCK SPECIFIED IN ELECTIONS TO BE PURCHASED UNDER ANY OFFERING PLUS
THE NUMBER OF SHARES PURCHASED UNDER PREVIOUS OFFERINGS UNDER THIS PLAN EXCEEDS
THE MAXIMUM NUMBER OF SHARES ISSUABLE UNDER THIS PLAN, THE BOARD OR THE
COMMITTEE WILL ALLOT THE SHARES THEN AVAILABLE ON A PRO RATA BASIS.

19.           TERMINATION OF THE PLAN.  THIS PLAN MAY BE TERMINATED AT ANY TIME
BY THE BOARD.  UPON TERMINATION OF THIS PLAN ALL AMOUNTS IN THE ACCOUNTS OF
PARTICIPATING EMPLOYEES SHALL BE PROMPTLY REFUNDED.

20.           GOVERNMENTAL REGULATIONS.  THE COMPANY’S OBLIGATION TO SELL AND
DELIVER COMMON STOCK UNDER THIS PLAN IS SUBJECT TO LISTING ON A NATIONAL STOCK
EXCHANGE OR QUOTATION ON THE NASDAQ

4

--------------------------------------------------------------------------------

NATIONAL MARKET (TO THE EXTENT THE COMMON STOCK IS THEN SO LISTED OR QUOTED) AND
THE APPROVAL OF ALL GOVERNMENTAL AUTHORITIES REQUIRED IN CONNECTION WITH THE
AUTHORIZATION, ISSUANCE OR SALE OF SUCH STOCK.

21.           GOVERNING LAW.  THE PLAN SHALL BE GOVERNED BY DELAWARE LAW EXCEPT
TO THE EXTENT THAT SUCH LAW IS PREEMPTED BY FEDERAL LAW.

22.           ISSUANCE OF SHARES.  SHARES MAY BE ISSUED UPON EXERCISE OF AN
OPTION FROM AUTHORIZED BUT UNISSUED COMMON STOCK, FROM SHARES HELD IN THE
TREASURY OF THE COMPANY, OR FROM ANY OTHER PROPER SOURCE.

23.           NOTIFICATION UPON SALE OF SHARES.  EACH EMPLOYEE AGREES, BY
ENTERING THE PLAN, TO PROMPTLY GIVE THE COMPANY NOTICE OF ANY DISPOSITION OF
SHARES PURCHASED UNDER THE PLAN WHERE SUCH DISPOSITION OCCURS WITHIN TWO YEARS
AFTER THE DATE OF GRANT OF THE OPTION PURSUANT TO WHICH SUCH SHARES WERE
PURCHASED.

24.           WITHHOLDING. EACH EMPLOYEE SHALL, NO LATER THAN THE DATE OF THE
EVENT CREATING THE TAX LIABILITY, MAKE PROVISION SATISFACTORY TO THE BOARD FOR
PAYMENT OF ANY TAXES REQUIRED BY LAW TO BE WITHHELD IN CONNECTION WITH ANY
TRANSACTION RELATED TO OPTIONS GRANTED TO OR SHARES ACQUIRED BY SUCH EMPLOYEE
PURSUANT TO THE PLAN.  THE COMPANY MAY, TO THE EXTENT PERMITTED BY LAW, DEDUCT
ANY SUCH TAXES FROM ANY PAYMENT OF ANY KIND OTHERWISE DUE TO AN EMPLOYEE.

25.           EFFECTIVE DATE AND APPROVAL OF SHAREHOLDERS.  THE PLAN SHALL TAKE
EFFECT ON THE CLOSING OF THE COMPANY’S INITIAL PUBLIC OFFERING SUBJECT TO
APPROVAL BY THE SHAREHOLDERS OF THE COMPANY AS REQUIRED BY SECTION 423 OF THE
CODE, WHICH APPROVAL MUST OCCUR WITHIN TWELVE MONTHS OF THE ADOPTION OF THE PLAN
BY THE BOARD.

*        *        *

Adopted by the Board of Directors

on August 18, 2003

Approved by the stockholders

on October 6, 2003

5

--------------------------------------------------------------------------------

AMENDMENT NO. 1 TO
NITROMED, INC.
2003 EMPLOYEE STOCK PURCHASE PLAN

This Amendment No. 1 (the “Amendment”) is made to the 2003 Employee Stock
Purchase Plan (the “ESPP”) of NitroMed, Inc. (the “Company”), which was adopted
by the Board of Directors of the Company on August 18, 2003 and approved by its
stockholders in October 2003.

The introductory paragraph of the ESPP be and hereby is amended such that the
second sentence of such paragraph: “Seventy Five Thousand (75,000) shares of
Common Stock in the aggregate have been approved for this purpose” is hereby
deleted.

The ESPP be and hereby is further amended to add a new section 26 which shall
read:

“26. Shares Authorized for Issuance.    One Hundred Fifty Thousand (150,000)
shares of Common Stock in the aggregate have been approved for issuance under
the ESPP. In addition, beginning on January 1, 2007 (the “Evergreen Commencement
Date”) and ending on December 31, 2010 (the “Evergreen Termination Date”) the
number of shares of Common Stock authorized for issuance under the ESPP shall
automatically increase on the Evergreen Commencement Date and on each
anniversary of the Evergreen Commencement Date by the lesser of:

a)  150,000 shares; or

 

b)  a lesser amount as may be determined by the Board of Directors.”

 

Except as herein provided, all other terms and conditions of the ESPP remain
unchanged and in full force and effect. Capitalized terms used herein and not
otherwise defined herein shall have the respective meanings assigned to them in
the ESPP.

This Amendment was adopted by the Board of Directors of the Company on March 7,
2006.

This Amendment was adopted by the Stockholders of the Company on May 17, 2006.

6

--------------------------------------------------------------------------------