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                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
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                                 SCHEDULE 14D-9
                               (AMENDMENT NO. 4)
                     SOLICITATION/RECOMMENDATION STATEMENT
                          PURSUANT TO SECTION 14(D)(4)
                     OF THE SECURITIES EXCHANGE ACT OF 1934
                           AMERICAN CYANAMID COMPANY
                           (Name of Subject Company)
                           AMERICAN CYANAMID COMPANY
                      (Name of Person(s) Filing Statement)
 
                    COMMON STOCK, PAR VALUE $5.00 PER SHARE,
                  INCLUDING THE ASSOCIATED RIGHTS TO PURCHASE
                 SERIES A JUNIOR PARTICIPATING PREFERRED STOCK,
                           PAR VALUE $1.00 PER SHARE
                         (Title of Class of Securities)
 
                                   025321100
                     (CUSIP Number of Class of Securities)
 
                           JOSEPH S. MCAULIFFE, ESQ.
                       VICE PRESIDENT AND GENERAL COUNSEL
                           AMERICAN CYANAMID COMPANY
                               ONE CYANAMID PLAZA
                            WAYNE, NEW JERSEY 07470
                                 (201) 831-2000
                                    COPY TO:
                              PETER D. LYONS, ESQ.
                              SHEARMAN & STERLING
                              599 LEXINGTON AVENUE
                            NEW YORK, NEW YORK 10022
                                 (212) 848-4000
 
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    This Amendment No. 4 amends and supplements the Solicitation/Recommendation
Statement on Schedule 14D-9 dated August 23, 1994, as amended, of American
Cyanamid Company, a Maine corporation (the "Company"), with respect to the
tender offer made by AC Acquisition Corp., a Delaware corporation (the
"Purchaser") and a wholly owned subsidiary of American Home Products
Corporation, a Delaware corporation ("Parent"), to purchase all the outstanding
shares of Common Stock, par value $5.00 per share of the Company (the "Shares"),
including the associated rights (the "Rights") to purchase shares of Series A
Junior Participating Preferred Stock, par value $1.00 per share.
 
ITEM 3. IDENTITY AND BACKGROUND.

    Item 3 is amended and supplemented by inserting at the end of the first 
paragragh under the heading "The Offer", the following:

        The Company, subject to the consent of the Purchaser and Parent, which 
    the company anticipates obtaining, intends, not withstanding the terms of 
    the Merger Agreements to accelerate the date upon which all outstanding 
    stock options shall be cancelled in exchange for the payment provided for 
    in Section 2.7 of the Merger Agreement, so that instead of occurring 
    immediately prior to the Effective Time, this cancellation and payment 
    shall take place immediately prior to the purchase of the Shares pursuant 
    to the Offer.
 
    Item 3 is further amended and supplemented by inserting at the end of the 
second paragraph under the heading "The Merger", the following:
 
        For a description of the effect which tendering Shares into the Offer
    has upon these rights, see paragraph 2 of the amendment to Item 8 contained
    in this Amendment No. 4.
 
ITEM 4. THE SOLICITATION OR RECOMMENDATION.
 
    Item 4 is amended and supplemented by inserting at the end of the last
paragraph, the following:
 

        For a description of additional aspects of the Board of Directors'
    deliberative process, see paragraph 2 of the amendment to Item 8 contained
    in this Amendment No. 4.

 
ITEM 8. ADDITIONAL INFORMATION TO BE FURNISHED.
 
    Item 8 is amended and supplemented by adding thereto after the heading
"Stockholder Litigation" the following:
 
        On November 17, 1994, the Defendants, Parent and counsel for plaintiffs
    entered into a Memorandum of Understanding ("MOU") providing for the
    settlement of the litigation (the "Settlement") by plaintiffs, the class of
    persons on behalf of whom plaintiffs have brought the litigation, the
    Company, the individual defendants, and Parent on the following terms and
    conditions, among others:
 
       1. The termination fee that the Company is obligated to pay to Parent
          under certain circumstances described in Section 8.3 of the Merger
          Agreement, in the event the Offer and the Merger are not consummated,
          shall be reduced from $100 million in cash to $90 million in cash.
 

       2. This Schedule 14D-9 shall be amended to include the following
          additional disclosures: (a) stockholders of the Company that tender
          Shares to Purchaser pursuant to the Merger, thereby forfeit any
          appraisal rights they would otherwise have in connection with the
          Merger, (b) the Company never formally invited other formal
          acquisition proposals, although the Company believes that it performed
          a thorough market check and that the Board of Directors fulfilled its
          fiduciary obligations in connection with the Offer and the Merger (c)
          the Company received general expressions of interest in possible
          transactions with the Company from two other well established
          pharmaceutical companies prior to its entry into the Merger Agreement.

 

       3. The Defendants agree to stipulate jointly with plaintiffs, solely for
          purposes of effectuating the Settlement, to the conditional
          certification of a class of stockholder plaintiffs as to be defined in
          the stipulation of settlement.

 
       4. The Defendants agree to submit to the New Jersey Supreme Court,
          Chancery Division, jointly with plaintiffs, the Settlement and to take
          no position upon the application of plaintiffs counsel for an award of
          attorneys' fees in an amount not to exceed in the aggregate $200,000
          and reimbursement of expenses not to exceed in the aggregate $20,000.
 
    Plaintiffs and the Defendants intend to submit the Settlement to the
Chancery Court for its approval, upon a hearing to be held after notice to the
members of the plaintiff class. This hearing has not yet been held and the
approval of the court has not yet been obtained.
 
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                                   SIGNATURE
 
    After reasonable inquiry and to the best of my knowledge and belief, I
certify that the information set forth in this Statement is true, complete and
correct.
 
                                 AMERICAN CYANAMID COMPANY

                                By:       /s/ JOSEPH S. MCAULIFFE
                                     ..................................

                                     Name: Joseph S. McAuliffe
                                    Title:  Vice President and General Counsel
 
Dated: November 17, 1994
 
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