8-K

                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON D.C. 20549

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


                                    FORM 8-K


                                 CURRENT REPORT
                     Pursuant to Section 13 or 15(d) of the
                         Securities Exchange Act of 1934


Date of report (Date of earliest event reported):  October 5, 2005


                              The Medicines Company
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               (Exact Name of Registrant as Specified in Charter)


          Delaware                  000-31191                   04-3324394
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(State or Other Jurisdiction       (Commission                 (IRS Employer
      of Incorporation)            File Number)             Identification No.)


            8 Campus Drive
         Parsippany, New Jersey                                       07054
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 (Address of Principal Executive Offices)                           (Zip Code)

Registrant's telephone number, including area code: (973) 656-1616


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          (Former Name or Former Address, if Changed Since Last Report)

Check the appropriate box below if the Form 8-K filing is intended to
simultaneously satisfy the filing obligation of the registrant under any of the
following provisions (see General Instruction A.2. below):

|_|  Written communications pursuant to Rule 425 under the Securities Act (17
     CFR 230.425)

|_|  Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR
     240.14a-12)

|_|  Pre-commencement communications pursuant to Rule 14d-2(b) under the
     Exchange Act (17 CFR 240.14d-2(b))

|_|  Pre-commencement communications pursuant to Rule 13e-4(c) under the
     Exchange Act (17 CFR 240.13e-4(c))




Item 2.02. Results of Operations and Financial Condition.

     On October 5, 2005, The Medicines Company (the "Company") announced revised
2005 financial guidance and preliminary financial results for the quarter ended
September 30, 2005. The full text of the press release issued in connection with
the announcement is furnished as Exhibit 99.1 to this Current Report on Form
8-K.

     The information in this Form 8-K (including Exhibit 99.1) shall not be
deemed "filed" for purposes of Section 18 of the Securities Exchange Act of 1934
(the "Exchange Act") or otherwise subject to the liabilities of that section,
nor shall it be deemed incorporated by reference in any filing under the
Securities Act of 1933 or the Exchange Act, except as expressly set forth by
specific reference in such a filing.

Item 9.01. Financial Statements and Exhibits

     (c)  Exhibits

          The following exhibit relating to Item 2.02 shall be deemed to be
          furnished, and not filed:

          99.1 Press Release dated October 5, 2005 entitled "The Medicines
               Company Lowers 2005 Guidance."




                                   SIGNATURES


     Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned hereunto duly authorized.

                                             THE MEDICINES COMPANY


Date: October 5, 2005                        By: /s/ Steven H. Koehler
                                                 ---------------------
                                                 Steven H. Koehler
                                                 Senior Vice President and Chief
                                                 Financial Officer




                                  Exhibit Index


Exhibit No.              Description
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99.1                     Press release dated October 5, 2005 entitled "The
                         Medicines Company Lowers 2005 Guidance."

EX-99.1

                                                                    Exhibit 99.1

                  THE MEDICINES COMPANY LOWERS 2005 GUIDANCE

                   Reports Preliminary Third Quarter Results

    PARSIPPANY, N.J.--(BUSINESS WIRE)--Oct. 5, 2005--The Medicines
Company (NASDAQ: MDCO) today lowered its revenue guidance for 2005
based on less growth than previously forecast in end-user demand for
Angiomax(R) (bivalirudin) and the restructuring of the Company's
wholesaler arrangements. The Company has agreed with its largest
wholesalers to enter into new fee-for-service arrangements that the
Company expects will improve its margins, create more predictable
buying patterns, and result in reductions in wholesaler inventories.
    The Company now expects 2005 net revenues of approximately $150
million. Previously, the Company had said it expected net revenues for
2005 at the lower end of a range of $195 million to $204 million.
    Based on revenues to date and lower product sales expected to
result in the short term from the restructured wholesaler
arrangements, the Company now expects a 2005 loss of approximately $10
million, as compared to previous guidance of 2005 earnings at the low
end of a range of $24 million to $31 million. For the third quarter
ended September 30, 2005, the Company, on a preliminary basis, expects
to report net revenues of approximately $30 million and a net loss of
approximately $10 million.
    The Company expects the restructured arrangements with wholesalers
to provide:

    --  competitive distribution costs, improving margins by 1-2%;

    --  an end to speculative buying by wholesalers, leading to lower
        inventory levels;

    --  more predictable buying patterns, resulting in more consistent
        accounts receivable;

    --  more frequent data on inventory, providing better planning and
        control; and

    --  guaranteed customer order fulfillment at a rate of 98%.

    As a result, aggregate wholesaler inventory levels are expected to
be reduced from an average of 14 weeks to four to six weeks by the end
of the first quarter of 2006. These inventory reductions are expected
to reduce reported net sales to wholesalers by approximately $26
million in 2005 and $13 million in the first quarter of 2006.
    Clive Meanwell, Chairman and Chief Executive Officer, said, "In a
sluggish cath lab market, Angiomax hospital sales have grown by 42%
this year compared to last year, but we are about $19 million below
our ambitious hospital sales plan for 2005. In addition, we believe
that wholesaler changes will strengthen our future performance and
that the benefits outweigh the short-term pain."
    John Kelley, President and Chief Operating Officer, said, "In the
past year, we have increased market share for Angiomax in PCI from 26%
to 33%. We expect to continue to grow and gain market share as our new
label and increased selling resources take effect. We are also looking
forward to a series of important events over the coming months
including completion of the ACUITY trial this year and presentation of
results at the ACC conference next March and starting Cangrelor Phase
III trials."

    Conference Call

    The Company will host a conference call with management today at
5:00 p.m. EDT to discuss this announcement as well as updates on
potential new indications for Angiomax and developments concerning
Clevidipine and Cangrelor.

    The webcast and accompanying slides can be accessed at
www.themedicinescompany.com. Alternatively, the call dial-in is
800-638-4930, passcode is 79545099. From outside the U.S., dial
617-614-3944 (passcode is 79545099). The replay will be available
following the call at 7.30 p.m. EDT for two weeks. The replay can be
accessed by dialing 888-286-8010. Outside the U.S., dial 617-801-6888.
The replay passcode is 36223991.

    About The Medicines Company

    The Medicines Company (NASDAQ: MDCO) meets the demands of the
world's most advanced medical practitioners by developing products
that improve acute hospital care. The Company markets Angiomax(R)
(bivalirudin), an anti-clotting therapy approved in the U.S. and other
countries for use in patients undergoing coronary angioplasty, a
procedure to clear restricted blood flow in arteries around the heart.
The Medicines Company creates value using its range of clinical and
commercial skills to develop products acquired from leading life
science innovators.

    Statements contained in this press release about The Medicines
Company, the Company's projected revenues and financial results for
the third quarter of 2005 and the full year 2005, Angiomax, the timing
of clinical trial results and product or indication launches, and all
other statements that are not purely historical, may be deemed to be
forward-looking statements for purposes of the safe harbor provisions
under The Private Securities Litigation Reform Act of 1995. Without
limiting the foregoing, the words "believes", "anticipates", "plans",
"expects", "intends", "potential", "estimates" and similar expressions
are intended to identify forward-looking statements. These
forward-looking statements involve known and unknown risks and
uncertainties that may cause the Company's actual results, levels of
activity, performance or achievements to be materially different from
those expressed or implied by these forward-looking statements.
Important factors that may cause or contribute to such differences
include the extent of the commercial success of Angiomax, the
Company's dependence on wholesalers and international distribution
partners for sales of Angiomax and the fluctuation of revenues based
on the buying patterns of these wholesalers and international
distribution partners, the success of the arrangements with the
Company's wholesalers referred to in this release, that these
wholesaler arrangements are subject to termination on short notice,
completion of accounting procedures with respect to the third quarter
of 2005, physicians' acceptance of Angiomax clinical trial results,
whether the Company will be able to obtain regulatory approval for
additional indications of Angiomax, whether the Company's products
will receive approvals from regulatory agencies, whether the Company's
products will advance in the clinical trials process, whether the
clinical trial results will warrant submission of applications for
regulatory approval, and such other factors as are set forth in the
risk factors detailed from time to time in the Company's periodic
reports filed with the Securities and Exchange Commission including,
without limitation, the risk factors detailed in the Company's
Quarterly Report on Form 10-Q filed on August 8, 2005, which are
incorporated herein by reference. The Company specifically disclaims
any obligation to update these forward-looking statements.

    CONTACT: The Medicines Company
             Michael Mitchell, 973-656-1616
             investor.relations@themedco.com