1
                       SECURITIES AND EXCHANGE COMMISSION

                             Washington, D.C. 20549

                                    FORM 10-Q




(Mark One)

[X]      QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
         EXCHANGE ACT OF 1934

         For the quarterly period ended March 31, 2001


                                       OR

[ ]      TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
         EXCHANGE ACT OF 1934

         For the transition period from           to
                                        ---------    ---------


                           Commission File No. 1-3305


                                MERCK & CO., INC.
                                  P. O. Box 100
                                 One Merck Drive
                       Whitehouse Station, N.J. 08889-0100
                                 (908) 423-1000


                                               
Incorporated in New Jersey                        I.R.S. Employer Identification
                                                  No. 22-1109110



The number of shares of common stock outstanding as of the close of business on
April 30, 2001:



            Class                           Number of Shares Outstanding
            -----                           ----------------------------
                                         
            Common Stock                            2,293,004,923


Indicate by check mark whether the registrant (1) has filed all reports required
to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during
the preceding 12 months (or for such shorter period that the registrant was
required to file such reports) and (2) has been subject to such filing
requirements for the past 90 days.

                                           Yes  X           No
                                               ---             ---
   2
Part I - Financial Information



                       MERCK & CO., INC. AND SUBSIDIARIES
                    INTERIM CONSOLIDATED STATEMENT OF INCOME
                   THREE MONTHS ENDED MARCH 31, 2001 AND 2000
               (Unaudited, $ in millions except per share amounts)



                                                           Three Months
                                                          Ended March 31
                                                  ----------------------------
                                                     2001              2000
                                                  ----------        ----------
                                                              
Sales                                             $ 11,345.1        $  8,851.4
                                                  ----------        ----------

Costs, Expenses and Other

  Materials and production                           7,046.5           4,833.4

  Marketing and administrative                       1,506.2           1,417.2

  Research and development                             547.4             523.6

  Equity income from affiliates                       (178.6)           (188.3)

  Other (income) expense, net                           56.1              71.5
                                                  ----------        ----------

                                                     8,977.6           6,657.4
                                                  ----------        ----------

Income Before Taxes                                  2,367.5           2,194.0

Taxes on Income                                        710.2             694.4
                                                  ----------        ----------

Net Income                                        $  1,657.3        $  1,499.6
                                                  ==========        ==========



Basic Earnings per Common Share                         $.72              $.65

Earnings per Common Share Assuming Dilution             $.71              $.63

Dividends Declared per Common Share                     $.34              $.29



               The accompanying notes are an integral part of this
                        consolidated financial statement.

                                      - 1 -
   3
                       MERCK & CO., INC. AND SUBSIDIARIES
                           CONSOLIDATED BALANCE SHEET
                      MARCH 31, 2001 AND DECEMBER 31, 2000
                           (Unaudited, $ in millions)



                                                                March 31       December 31
                                                                  2001            2000
                                                               ---------       ---------
                                                                         
ASSETS
  Current Assets
    Cash and cash equivalents                                  $ 2,158.5       $ 2,536.8
    Short-term investments                                       1,841.6         1,717.8
    Accounts receivable                                          5,009.8         5,017.9
    Inventories                                                  2,845.6         3,021.5
    Prepaid expenses and taxes                                     996.2         1,059.4
                                                               ---------       ---------

      Total current assets                                      12,851.7        13,353.4
                                                               ---------       ---------

  Investments                                                    5,317.4         4,947.8

  Property, Plant and Equipment, at cost,
    net of allowance for depreciation of
    $5,395.4 in 2001 and $5,225.1 in 2000                       11,836.0        11,482.1

  Goodwill and Other Intangibles,
    net of accumulated amortization of
    $1,942.2 in 2001 and $1,850.7 in 2000                        7,283.7         7,374.2

  Other Assets                                                   2,937.5         2,752.9
                                                               ---------       ---------
                                                               $40,226.3       $39,910.4
                                                               =========       =========
LIABILITIES AND STOCKHOLDERS' EQUITY
  Current Liabilities
     Accounts payable and accrued liabilities                  $ 4,162.6       $ 4,361.3
     Loans payable and current portion of long-term debt         3,778.2         3,319.3
     Income taxes payable                                        1,672.9         1,244.3
     Dividends payable                                             783.1           784.7
                                                               ---------       ---------

      Total current liabilities                                 10,396.8         9,709.6
                                                               ---------       ---------

  Long-Term Debt                                                 3,623.1         3,600.7
                                                               ---------       ---------

  Deferred Income Taxes and Noncurrent Liabilities               6,427.7         6,746.7
                                                               ---------       ---------

  Minority Interests                                             4,922.0         5,021.0
                                                               ---------       ---------

  Stockholders' Equity
    Common stock
     Authorized - 5,400,000,000 shares
     Issued     - 2,968,379,125 shares - March 31, 2001
                - 2,968,355,365 shares - December 31, 2000          29.7            29.7
    Other paid-in capital                                        6,266.8         6,265.8
    Retained earnings                                           28,238.1        27,363.9
    Accumulated other comprehensive income                         107.0            30.8
                                                               ---------       ---------
                                                                34,641.6        33,690.2

    Less treasury stock, at cost
     670,901,233 shares - March 31, 2001
     660,756,186 shares - December 31, 2000                     19,784.9        18,857.8
                                                               ---------       ---------

      Total stockholders' equity                                14,856.7        14,832.4
                                                               ---------       ---------
                                                               $40,226.3       $39,910.4
                                                               =========       =========


               The accompanying notes are an integral part of this
                       consolidated financial statement.

                                      - 2 -
   4
                       MERCK & CO., INC. AND SUBSIDIARIES
                  INTERIM CONSOLIDATED STATEMENT OF CASH FLOWS
                   THREE MONTHS ENDED MARCH 31, 2001 AND 2000
                   ------------------------------------------
                           (Unaudited, $ in millions)



                                                                                 Three Months
                                                                                Ended March 31
                                                                           ------------------------
                                                                             2001            2000
                                                                           --------        --------
                                                                                     
CASH FLOWS FROM OPERATING ACTIVITIES
Income before taxes                                                        $2,367.5        $2,194.0
  Adjustments to reconcile income before taxes to cash provided from
   operations before taxes:
     Depreciation and amortization                                            360.2           319.9
     Other                                                                   (198.6)          (87.7)
     Net changes in assets and liabilities                                    145.9           (28.2)
                                                                           --------        --------
CASH PROVIDED BY OPERATING ACTIVITIES BEFORE TAXES                          2,675.0         2,398.0
INCOME TAXES PAID                                                            (502.3)         (314.1)
                                                                           --------        --------
NET CASH PROVIDED BY OPERATING ACTIVITIES                                   2,172.7         2,083.9
                                                                           --------        --------

CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures                                                         (632.8)         (504.3)
Purchase of securities, subsidiaries and other investments                 (8,227.2)       (8,407.9)
Proceeds from sale of securities, subsidiaries and other investments        7,732.5         8,448.4
Other                                                                         (30.1)           71.9
                                                                           --------        --------
NET CASH USED BY INVESTING ACTIVITIES                                      (1,157.6)         (391.9)
                                                                           --------        --------

CASH FLOWS FROM FINANCING ACTIVITIES
Net change in short-term borrowings                                           (22.7)         (471.0)
Proceeds from issuance of debt                                                526.0           300.0
Payments on debt                                                               (4.0)          (67.1)
Proceeds from issuance of preferred units of subsidiary                          --         1,500.0
Purchase of treasury stock                                                 (1,018.7)       (2,142.9)
Dividends paid to stockholders                                               (784.7)         (677.0)
Other                                                                         (28.0)           94.9
                                                                           --------        --------
NET CASH USED BY FINANCING ACTIVITIES                                      (1,332.1)       (1,463.1)
                                                                           --------        --------

EFFECT OF EXCHANGE RATE CHANGES ON CASH AND CASH EQUIVALENTS                  (61.3)          (28.1)
                                                                           --------        --------

NET (DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS                         (378.3)          200.8
CASH AND CASH EQUIVALENTS AT BEGINNING OF YEAR                              2,536.8         2,021.9
                                                                           --------        --------
CASH AND CASH EQUIVALENTS AT END OF PERIOD                                 $2,158.5        $2,222.7
                                                                           ========        ========


                          The accompanying notes are an
            integral part of this consolidated financial statement.


Notes to Consolidated Financial Statements

1.   The accompanying unaudited interim consolidated financial statements have
     been prepared pursuant to the rules and regulations for reporting on Form
     10-Q. Accordingly, certain information and disclosures required by
     accounting principles generally accepted in the United States for complete
     consolidated financial statements are not included herein. The interim
     statements should be read in conjunction with the financial statements and
     notes thereto included in the Company's latest Annual Report on Form 10-K.

     Interim statements are subject to possible adjustments in connection with
     the annual audit of the Company's accounts for the full year 2001; in the
     Company's opinion, all adjustments necessary for a fair presentation of
     these interim statements have been included and are of a normal and
     recurring nature.

     Certain reclassifications have been made to prior year amounts to conform
     with current year presentation.

                                      -3-
   5
Notes to Consolidated Financial Statements (continued)

2.   Inventories consisted of:



                                                   ($ in millions)
                                               ------------------------
                                               March 31     December 31
                                                 2001          2000
                                               --------     -----------
                                                      
         Finished goods                        $1,714.6       $1,762.8
         Raw materials and work in process      1,051.6        1,174.9
         Supplies                                  79.4           83.8
                                               --------       --------
           Total (approximates current cost)    2,845.6        3,021.5
         Reduction to LIFO cost                      --             --
                                               --------       --------
                                               $2,845.6       $3,021.5
                                               ========       ========


3.   In February 2001, the Company issued $500.0 million of notes with annual
     interest rate resets and a final maturity of ten years. On an annual basis,
     the notes will either be repurchased from the holders at the option of the
     remarketing agent and remarketed, or redeemed by the Company. The notes are
     reported in Loans payable and current portion of long-term debt.

4.   The Company, along with numerous other defendants, is a party in several
     antitrust actions brought by retail pharmacies and consumers, alleging
     conspiracies in restraint of trade and challenging pricing and/or
     purchasing practices, one of which has been certified as a federal class
     action and a number of which have been certified as state class actions. In
     1996, the Company and several other defendants finalized an agreement to
     settle the federal class action alleging conspiracy, which represents the
     single largest group of retail pharmacy claims. Since that time, the
     Company has entered into other settlements on satisfactory terms. The
     Company has not engaged in any conspiracy, and no admission of wrongdoing
     was made nor was included in the final agreements. While it is not feasible
     to predict or determine the final outcome of these proceedings, management
     does not believe that they should result in a materially adverse effect on
     the Company's financial position, results of operations or liquidity.

5.   Sales consisted of:



                                                         ($ in millions)
                                                  ---------------------------
                                                          Three Months
                                                         Ended March 31
                                                  ---------------------------
                                                      2001            2000
                                                  ----------      ----------
                                                             
          Atherosclerosis                          $ 1,662.7       $ 1,284.3
          Hypertension/heart failure                 1,017.5         1,138.3
          Anti-inflammatory/analgesics                 506.6           391.6
          Osteoporosis                                 349.2           276.7
          Respiratory                                  297.7           167.0
          Vaccines/biologicals                         238.7           208.6
          Antibiotics                                  188.1           189.9
          Anti-ulcerants                               186.9           206.8
          Ophthalmologicals                            162.9           156.2
          Human immunodeficiency virus (HIV)           123.7           138.3
          Other Merck products                         228.7           458.4
          Merck-Medco                                6,382.4         4,235.3
                                                   ---------       ---------
                                                   $11,345.1       $ 8,851.4
                                                   =========       =========


     Other Merck products include sales of other human pharmaceuticals,
     continuing sales to divested businesses and pharmaceutical and animal
     health supply sales to the Company's joint ventures and AstraZeneca LP.
     Also included are rebates and discounts on Merck pharmaceutical products.


                                      -4-
   6
Notes to Consolidated Financial Statements (continued)


6.   Other (income) expense, net, consisted of:



                                                                   ($ in millions)
                                                               ----------------------
                                                                    Three Months
                                                                   Ended March 31
                                                               ----------------------
                                                                 2001           2000
                                                               -------        -------
                                                                        
          Interest income                                      $(136.1)       $ (94.7)
          Interest expense                                       110.7          117.3
          Exchange gains, net                                    (12.6)          (7.8)
          Minority interests                                      85.2           60.2
          Amortization of goodwill and other intangibles          80.6           78.8
          Other, net                                             (71.7)         (82.3)
                                                               -------        -------
                                                               $  56.1        $  71.5
                                                               =======        =======


     Minority interests include third parties' share of exchange gains and
     losses arising from translation of the financial statements into U.S.
     dollars.

     Interest paid for the three-month periods ended March 31, 2001 and 2000 was
     $128.9 million and $120.3 million, respectively.

7.   Income taxes paid for the three-month periods ended March 31, 2001 and 2000
     were $502.3 million and $314.1 million, respectively.

8.   The net income effect of dilutive securities was not significant to the
     Company's calculation of Earnings per common share assuming dilution. A
     reconciliation of weighted average common shares outstanding to weighted
     average common shares outstanding assuming dilution follows:



                                                                (shares in millions)
                                                               ---------------------
                                                                    Three Months
                                                                   Ended March 31
                                                               ---------------------
                                                                 2001          2000
                                                               -------       -------
                                                                       
     Average common shares outstanding                         2,303.7       2,317.5
     Common shares issuable(1)                                    42.2          45.6
                                                               -------       -------
     Average common shares outstanding assuming dilution       2,345.9       2,363.1
                                                               =======       =======


     (1)  Issuable primarily under stock option plans.

9.   Effective January 1, 2001, the Company adopted the provisions of Statement
     No. 133, Accounting for Derivative Instruments and Hedging Activities (FAS
     133), which establishes accounting and reporting standards requiring that
     every derivative instrument be recorded in the balance sheet as either an
     asset or liability measured at fair value and that changes in fair value be
     recognized currently in earnings unless specific hedge accounting criteria
     are met. Upon adoption of the Statement, the Company recorded a favorable
     cumulative effect of accounting change of $45.5 million after tax in Other
     comprehensive income (loss), representing the mark to fair value of
     purchased local currency put options. (See Note 10 for further
     information.) The cumulative effect of accounting change recorded in Net
     income was not significant.

     Foreign Currency Risk Management

     A significant portion of the Company's cash flows are denominated in
     foreign currencies. Merck relies on sustained cash flows generated from
     foreign sources to support its long-term commitment to U.S. dollar-based
     research and development. To the extent the dollar value of cash flows is
     diminished as a result of a strengthening dollar, the Company's ability to
     fund research and other dollar-based strategic initiatives at a consistent
     level may be impaired. The Company has established revenue hedging and
     balance sheet risk management programs to protect against volatility of
     future foreign currency cash flows and changes in fair value caused by
     volatility in foreign exchange rates.


                                      -5-
   7
Notes to Consolidated Financial Statements (continued)

     The objective of the revenue hedging program is to reduce the potential for
     longer-term unfavorable changes in foreign exchange to decrease the U.S.
     dollar value of future cash flows derived from foreign currency denominated
     sales, primarily the euro and Japanese yen. To achieve this objective, the
     Company will partially hedge anticipated sales that are expected to occur
     over its planning cycle, typically no more than three years into the
     future. The Company will layer in hedges over time, increasing the portion
     of sales hedged as it gets closer to the expected date of the transaction.
     The portion of sales hedged is based on assessments of cost-benefit
     profiles that consider natural offsetting exposures, revenue and exchange
     rate volatilities and correlations, and the cost of hedging instruments.
     Merck manages its anticipated transaction exposure principally with
     purchased local currency put options which provide the Company with a
     right, but not an obligation, to sell foreign currencies in the future at a
     predetermined price. If the U.S. dollar strengthens relative to the
     currency of the hedged anticipated sales, gains in the expected future cash
     flows of the options fully offset the decline in the expected future U.S.
     dollar cash flows of the hedged foreign currency sales. Conversely, if the
     U.S. dollar weakens, the options' value reduces to zero, but the Company
     benefits from the increase in the value of the anticipated foreign currency
     cash flows. During the first quarter of 2001, changes in the options'
     intrinsic value were deferred in Accumulated other comprehensive income
     (AOCI) until recognition of the hedged anticipated revenue. Amounts
     associated with option time value, which was excluded from the designated
     hedge relationship and marked to fair value in Marketing and administrative
     expenses, were not significant. In the second quarter of 2001, the
     designated hedge relationship will be based on changes in the options'
     expected future cash flows. Accordingly the entire fair value change in the
     options will be deferred in AOCI and reclassified into Sales when the
     hedged anticipated revenue is recognized. The fair value of purchased
     currency options is reported in Accounts receivable or Other assets.

     A primary objective of the balance sheet risk management program is to
     protect the U.S. dollar value of foreign currency denominated net monetary
     assets from the effects of volatility in foreign exchange that might occur
     prior to their conversion to U.S. dollars. To achieve this objective, the
     Company will manage foreign currency risk on monetary assets and
     liabilities when cost beneficial. Merck seeks to fully offset exposure
     denominated in developed country currencies, primarily the euro, Japanese
     yen and Canadian dollar, and will either partially offset or not offset at
     all exposure in other currencies, particularly exposure in developing
     countries where we consider the cost of instruments to be uneconomic or
     such instruments are unavailable at any cost. The Company will minimize the
     effect of exchange on exposed positions, principally by managing operating
     activities and net asset positions at the local level. Merck manages its
     net asset exposure principally with forward exchange contracts. These
     contracts enable the Company to buy and sell foreign currencies in the
     future at fixed exchange rates and offset the consequences of changes in
     foreign exchange on the amount of U.S. dollar cash flows derived from the
     net assets. Prior to conversion to U.S. dollars, monetary assets and
     liabilities are remeasured at spot rates in effect on the balance sheet
     date. The effects of changes in spot rates are reported in Other (income)
     expense, net. The forward contracts, which are not designated as hedges,
     are marked to forward through Other (income) expense, net. Fair value
     changes in the forward contracts offset the changes in the value of the
     remeasured assets and liabilities attributable to changes in foreign
     currency exchange rates, except to the extent of the spot-forward
     differences. These differences are not significant due to the short-term
     nature of the contracts, which typically have average maturities at
     inception of less than one year.

     The Company also uses forward contracts to hedge the changes in fair value
     of certain foreign currency denominated available-for-sale securities
     attributable to fluctuations in foreign currency exchange rates. Changes in
     the fair value of the hedged securities due to fluctuations in spot rates
     are offset in Other (income) expense, net, by fair value changes in the
     forward contracts also based on spot rates. Hedge ineffectiveness was not
     material for the quarter ended March 31, 2001. Changes in the contracts'
     fair value due to spot-forward differences are excluded from the designated
     hedge relationship and recognized in Other (income) expense, net. These
     amounts were not significant for the quarter ended March 31, 2001.

     The fair value of forward exchange contracts is reported in Accounts
     receivable, Other assets, Accounts payable and accrued liabilities or
     Deferred income taxes and noncurrent liabilities.

     Interest Rate Risk Management

     The Company may use interest rate swap contracts on certain investing and
     borrowing transactions. The Company does not use leveraged swaps and, in
     general, does not leverage any of its investment activities that would put
     principal capital at risk.


                                      -6-
   8
Notes to Consolidated Financial Statements (continued)

     The Company is a party to a seven-year combined interest rate and currency
     swap contract entered into in 1997 which converts a variable rate Dutch
     guilder investment to a variable rate U.S. dollar investment. The interest
     rate component of the swap is not designated as a hedge. The currency swap
     component is designated as a hedge of the changes in fair value of the
     investment attributable to exchange. Accordingly, changes in the fair value
     of the investment due to fluctuations in spot rates are offset in Other
     (income) expense, net, by fair value changes in the currency swap. Hedge
     ineffectiveness was not significant for the quarter ended March 31, 2001.
     The fair value of this contract is reported in Accounts receivable,
     Accounts payable and accrued liabilities or Other assets.

10.  Comprehensive income for the three months ended March 31, 2001 and 2000,
     representing all changes in Stockholders' equity during the period other
     than changes resulting from the Company's stock, was $1,733.5 million and
     $1,504.4 million, respectively. The amount for 2001 includes a favorable
     cumulative effect of accounting change of $45.5 million (net of $31.4
     million of income tax) from the January 1 adoption of FAS 133. This amount
     represented the mark to fair value of purchased local currency put options
     maturing throughout 2001 which hedge anticipated foreign currency
     denominated sales over that same period. (See Note 9 for further
     information.) At March 31, 2001, the net deferred gain associated with
     these options approximated $46.9 million (net of $32.5 million of income
     tax).

11.  The Company's operations are principally managed on a products and services
     basis and are comprised of two reportable segments: Merck Pharmaceutical,
     which includes products marketed either directly or through joint ventures,
     and Merck-Medco. Merck Pharmaceutical products consist of therapeutic
     agents, sold by prescription, for the treatment of human disorders.
     Merck-Medco revenues are derived from the filling and management of
     prescriptions and health management programs. All Other includes
     non-reportable human and animal health segments. Revenues and profits for
     these segments are as follows:



                                       ($ in millions)
                                  -------------------------
                                         Three Months
                                        Ended March 31
                                  -------------------------
                                     2001            2000
                                  ---------       ---------
                                            
     Segment revenues:
       Merck Pharmaceutical       $ 4,560.1       $ 4,223.8
       Merck-Medco                  7,212.1         4,949.5
       All Other                      302.3           269.9
                                  ---------       ---------
                                  $12,074.5       $ 9,443.2
                                  =========       =========
     Segment profits:
      Merck Pharmaceutical        $ 2,854.5       $ 2,655.8
      Merck-Medco                     142.0           142.3
      All Other                       228.4           186.8
                                  ---------       ---------
                                  $ 3,224.9       $ 2,984.9
                                  =========       =========


     Segment profits are comprised of segment revenues less certain elements of
     materials and production costs and operating expenses, including components
     of equity income from affiliates and depreciation and amortization
     expenses. The Company does not internally allocate the vast majority of
     indirect production costs, research and development expenses and general
     and administrative expenses, all predominantly related to the Merck
     pharmaceutical business, as well as the cost of financing these activities.
     Separate divisions maintain responsibility for monitoring and managing
     these costs, including depreciation related to fixed assets utilized by
     these divisions and, therefore, they are not included in the marketing
     segment profits. The vast majority of goodwill and other intangibles
     amortization, predominantly related to the Merck-Medco business, as well as
     the cost of financing capital employed, also are not allocated internally
     and, therefore, are not included in the marketing segment profits.


                                      -7-
   9
Notes to Consolidated Financial Statements (continued)

     A reconciliation of total segment profits to consolidated income before
taxes is as follows:



                                                ($ in millions)
                                           ------------------------
                                                  Three Months
                                                 Ended March 31
                                           ------------------------
                                             2001            2000
                                           --------        --------
                                                     
     Segment profits                       $3,224.9        $2,984.9
     Other profits                             72.3            91.1
     Adjustments                               73.0           121.1
     Unallocated:
       Interest income                        136.1            94.7
       Interest expense                      (110.7)         (117.3)
       Equity income from affiliates           68.3            78.4
       Depreciation and amortization         (285.4)         (260.8)
       Research and development              (547.4)         (523.6)
       Other expenses, net                   (263.6)         (274.5)
                                           --------        --------
                                           $2,367.5        $2,194.0
                                           ========        ========


     Other profits are primarily comprised of miscellaneous corporate profits as
     well as operating profits related to divested products or businesses and
     other supply sales. Adjustments represent the elimination of the effect of
     double counting certain items of income and expense. Equity income from
     affiliates includes taxes paid at the joint venture level and a portion of
     equity income that is not reported in segment profits. Other expenses, net,
     include expenses from corporate and manufacturing cost centers and other
     miscellaneous income (expense), net.

12.  Legal proceedings to which the Company is a party are discussed in Part 1
     Item 3, Legal Proceedings, in the 2000 Annual Report on Form 10-K. There
     were no material developments in the three month period ended March 31,
     2001.


                                      -8-
   10
             MANAGEMENT`S ANALYSIS OF INTERIM FINANCIAL INFORMATION

Earnings per share for the first quarter of 2001 were $0.71, an increase of 13%
over the first quarter of 2000. First quarter net income grew 11% to $1,657.3
million driven by a 28% sales increase for the quarter to $11.3 billion.

Sales growth was driven by Merck's human health products, which increased 8% for
the first quarter, and the Merck-Medco business. The unfavorable effect from
foreign exchange rates reduced the Company's human health sales growth by three
percentage points. Sales outside of the United States accounted for 37% of the
Company's first quarter human health sales.

Income growth for the quarter reflects strong worldwide sales volume gains led
by our five key growth drivers - 'Zocor', 'Vioxx', 'Cozaar' and 'Hyzaar'*,
'Fosamax' and 'Singulair' - which combined had increased sales of 30% over first
quarter 2000 sales. These five products now account for more than 60% of Merck's
worldwide human health sales. Together, they have created a solid platform for
growth for the Company, and it is this growth that allows Merck to continue its
strong investment in research and development.

'Zocor', Merck's cholesterol-modifying medicine, had another strong quarter with
worldwide sales reaching $1.5 billion in the first quarter of 2001. Physicians
continue to prescribe 'Zocor' in large part because of the medicine's
demonstrated ability to act favorably on all three key lipid parameters - LDL,
HDL and triglycerides. An estimated 11 million people in the United States have
both elevated LDL (bad cholesterol) and low levels of HDL (good cholesterol), as
defined by current National Cholesterol Education Program guidelines.

In the United States, the market for "statin" medicines, such as 'Zocor', is
expanding at almost 20% per year. Merck continues its consumer and education
awareness efforts in the United States because more than half of the people who
should be taking cholesterol medicines are still untreated.

'Vioxx', a once-a-day medicine, is the only COX-2 selective agent indicated in
the United States for both osteoarthritis and acute pain. Since its successful
1999 launch, 'Vioxx' has become the world's fastest-growing branded prescription
arthritis medicine, and it is already Merck's second largest-selling medicine.
'Vioxx' achieved $485 million in sales for the first quarter 2001.

Earlier this month, Merck received an approvable letter from the U.S. Food and
Drug Administration (FDA) regarding the Company's application for changes to
prescribing information for 'Vioxx' based on results from the 'Vioxx'
Gastrointestinal Outcomes Research (VIGOR) study. An approvable letter is
defined by the FDA as a written statement that the FDA will approve the
application if specific additional information or material is submitted or
specific conditions are met. An approvable letter does not constitute approval
of the application. Approvable letters may result in additional time for
completion of the FDA review.

'Cozaar' and 'Hyzaar', Merck's highly effective and well-tolerated high blood
pressure medicines, maintain their strong leadership of the angiotensin II
antagonists (AIIAs) class. Sales for the two products were $385 million for this
quarter. Despite an intensely competitive market, physicians continue to show
confidence in these products, prescribing them for more than 10 million patients
worldwide. Beginning in the first quarter of this year, Merck and DuPont now
share equally in the operating profits from 'Cozaar' and 'Hyzaar' in North
America, under the terms of the licensing agreement established between the
parties in 1989. Financial terms outside of North America are not affected.

'Fosamax', the leading product worldwide for the treatment and prevention of
postmenopausal osteoporosis, continues to outperform the competition because it
is the only osteoporosis medicine indicated and consistently proven to reduce
the incidence of osteoporotic fractures of the hip as well as the spine. Sales
totaled $350 million this quarter.

Merck's recent introduction of 'Fosamax' Once Weekly, the first and only oral
once-weekly treatment for osteoporosis, continues to bolster the competitive
position of 'Fosamax'. In the United States, 'Fosamax' Once Weekly has become
the No. 1 medicine for osteoporosis by a wide margin based on new prescriptions.
Regulatory approvals for 'Fosamax' Once Weekly continue in all parts of the
world. So far, the medicine has received medical approval in more than 45
countries and has been launched in 20 countries. In January 2001, the FDA
granted approval for 'Fosamax' Once Weekly to be considered by physicians as an
alternative to once-daily treatment for increasing bone mass in men with
osteoporosis.



*'Cozaar' and 'Hyzaar' are registered trademarks of E.I. du Pont de Nemours and
Company, Wilmington, DE, USA.

                                     -9-
   11
MANAGEMENT'S ANALYSIS OF INTERIM FINANCIAL INFORMATION (continued)

'Singulair', Merck's once-a-day leukotriene-antagonist, is the world's
fastest-growing asthma medicine. After only three years on the market,
'Singulair' has become the No. 1 asthma controller in terms of total
prescription sales on a weekly basis in the United States. Sales for this
quarter were $300 million. 'Singulair' is the first asthma controller therapy in
more than 15 years to be approved for children as young as two. Other benefits
include that it is a once-a-day tablet rather than an inhaled medication and
that it is not a steroid.

Merck is studying 'Singulair' as a potential treatment for seasonal allergic
rhinitis. The Company recently presented results from two clinical studies,
which showed that patients treated with 'Singulair' alone experienced
significant reductions in the common symptoms associated with seasonal allergic
rhinitis compared to patients treated with placebo.

Merck-Medco Managed Care, L.L.C. continued its strong contribution to Merck's
revenue growth in the first quarter of 2001. Internet volume through
merckmedco.com totaled 1.4 million prescriptions in the first quarter of 2001.
Merckmedco.com now processes more than 120,000 prescriptions per week.

Effective January 1, 2001, the Company adopted the provisions of Statement No.
133, Accounting for Derivative Instruments and Hedging Activities, which
establishes accounting and reporting standards requiring that every derivative
instrument be recorded in the balance sheet as either an asset or liability
measured at fair value and that changes in fair value be recognized currently in
earnings unless specific hedge accounting criteria are met. Upon adoption of the
Statement, the Company recorded a favorable cumulative effect of accounting
change of $45.5 million after tax in Other comprehensive income (loss),
representing the mark to fair value of purchased local currency put options.
(See Note 10 to the consolidated financial statements for further information.)
The cumulative effect of accounting change recorded in Net income was not
significant.

In January 2001, the FDA approved 'Cancidas' as the first in a new class of
antifungals, called echinocandins or glucan synthesis inhibitors, introduced in
more than a decade. Merck launched this new medicine in February 2001.
'Cancidas' will be used to treat certain life-threatening fungal infections that
are becoming more prevalent as the number of people with compromised immune
systems is increasing. The new medicine is indicated for the treatment of
invasive aspergillosis in patients who do not respond to or cannot tolerate
other antifungal therapies, such as amphotericin B, lipid formulations of
amphotericin B and/or itraconazole. 'Cancidas' has not been studied as an
initial therapy for invasive aspergillosis. Merck is studying 'Cancidas' as a
potential treatment for the fungal infection Candida.

On February 27, 2001, the Board of Directors declared a quarterly dividend of
34 cents per share on the Company's common stock, which was paid April 2 to
stockholders of record at the close of business on March 9. The Company's total
dividend paid to date in 2001 is 68 cents per share, a 17% increase over the
amount paid during the same period in 2000.

In March 2001, Merck-Medco joined with Advance PCS and Express Scripts to create
RxHub, an innovative, independent venture that will advance the efficiency and
safety of the prescription-writing process. The new system to be created by this
venture will allow physicians to electronically connect directly to
pharmacy-benefit managers, access patient-specific clinical information
(including formulary) and receive real-time notification of potential drug
interactions and side effects. The resulting prescription can be sent
electronically to the patient's preferred pharmacy for fulfillment.


                                      -10-
   12
CAUTIONARY FACTORS THAT MAY AFFECT FUTURE RESULTS

This report and other written reports and oral statements made from time to time
by the Company may contain so-called "forward-looking statements," all of which
are subject to risks and uncertainties. One can identify these forward-looking
statements by their use of words such as "expects," "plans," "will,"
"estimates," "forecasts," "projects" and other words of similar meaning. One can
also identify them by the fact that they do not relate strictly to historical or
current facts. These statements are likely to address the Company's growth
strategy, financial results, product approvals and development programs. One
must carefully consider any such statement and should understand that many
factors could cause actual results to differ from the Company's forward-looking
statements. These factors include inaccurate assumptions and a broad variety of
other risks and uncertainties, including some that are known and some that are
not. No forward-looking statement can be guaranteed and actual future results
may vary materially.

The Company does not assume the obligation to update any forward-looking
statement. One should carefully evaluate such statements in light of factors
described in the Company's filings with the Securities and Exchange Commission,
especially on Forms 10-K, 10-Q and 8-K (if any). In Item 1 of the Company's
Annual Report on Form 10-K for the year ended December 31, 2000, as filed on
March 23, 2001, the Company discusses in more detail various important factors
that could cause actual results to differ from expected or historic results. The
Company notes these factors for investors as permitted by the Private Securities
Litigation Reform Act of 1995. One should understand that it is not possible to
predict or identify all such factors. Consequently, the reader should not
consider any such list to be a complete statement of all potential risks or
uncertainties.


                                      -11-
   13
Part II - Other Information

Item 6.  Exhibits and Reports on Form 8-K

(a)  Exhibits



        Number        Description                                  Method of Filing
        ------        -----------                                  ----------------
                                                             
         3(a)         Restated Certificate of                      Incorporated by reference
                        Incorporation of Merck & Co., Inc.         to Form 10-Q Quarterly
                        (September 1, 2000)                        Report for the period ended
                                                                   September 30, 2000

         3(b)         By-Laws of Merck & Co., Inc.                 Incorporated by reference
                        (as amended effective                      to Form 10-Q Quarterly
                        February 25, 1997)                         Report for the period ended
                                                                   March 31, 1997

         12           Computation of Ratios of                     Filed with this document
                        Earnings to Fixed Charges


(b)  Reports on Form 8-K

          During the three-month period ending March 31, 2001, the Company:

          (i)  filed one Current Report on Form 8-K under Item 9 - Regulation FD
               Disclosure: Report dated January 23, 2001 and filed January 23,
               2001, regarding earnings for fourth quarter and certain
               supplemental information; and

          (ii) furnished one Current Report on Form 8-K under Item 9 -
               Regulation FD Disclosure: Report dated February 15, 2001 and
               furnished February 15, 2001, regarding financial guidance for
               2001.


                                      -12-
   14
                                   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 thereunto duly authorized.



                                       MERCK & CO., INC.



Date:  May 10, 2001                    /s/ Kenneth C. Frazier
                                       ----------------------
                                       KENNETH C. FRAZIER
                                       Senior Vice President and General Counsel


Date:  May 10, 2001                    /s/ Richard C. Henriques
                                       ------------------------
                                       RICHARD C. HENRIQUES
                                       Vice President, Controller



                                      -13-
   15
                                  EXHIBIT INDEX




             Exhibits
             --------

             Number           Description
             ------           -----------
                           
             3(a)             Restated Certificate of Incorporation of Merck & Co., Inc. (September 1, 2000)
                               - Incorporated by reference to Form 10-Q Quarterly Report for the period ended
                                  September 30, 2000

             3(b)             By-Laws of Merck & Co., Inc. (as amended effective February 25, 1997)
                               - Incorporated by reference to Form 10-Q Quarterly Report for the period ended
                                  March 31, 1997

             12               Computation of Ratios of Earnings to Fixed Charges