Exhibit 99.1
[MERCK] News Release
- --------------------------------------------------------------------------------

Media Contacts: Tony Plohoros Investor Contact: Michael Rabinowitz
(908) 423-3644 (908) 423-5185

Anita Larsen
(908) 423-6022

MERCK ANNOUNCES THIRD-QUARTER 2004 EARNINGS PER SHARE (EPS) OF 60 CENTS

o EARNINGS PER SHARE (EPS) OF 60 CENTS INCLUDES NEGATIVE IMPACT
OF 25 CENTS ASSOCIATED WITH VOLUNTARY WORLDWIDE WITHDRAWAL OF
VIOXX

o MERCK ANTICIPATES FOURTH-QUARTER EPS OF 48 TO 53 CENTS
INCLUDING EFFECT OF WITHDRAWAL OF VIOXX

o MERCK ANTICIPATES FULL-YEAR 2004 EPS GUIDANCE OF $2.59 TO
$2.64 INCLUDING EFFECT OF WITHDRAWAL OF VIOXX

o MERCK/SCHERING-PLOUGH PHARMACEUTICALS LAUNCHES VYTORIN IN
UNITED STATES

o HEAD-TO-HEAD STUDY SHOWS FOSAMAX ONCE WEEKLY SIGNIFICANTLY
GREATER THAN ACTONEL ONCE-A-WEEK IN INCREASING BONE MINERAL
DENSITY

o MERCK TO INCREASE SUPPLY OF PNEUMOVAX 23 (PNEUMOCOCCAL VACCINE
POLYVALENT) BY 11 MILLION DOSES

WHITEHOUSE STATION, N.J., Oct. 21, 2004 - Merck & Co., Inc. today announced that
earnings per share (EPS) for the third quarter of 2004 were $0.60, including a
$0.25 unfavorable effect associated with the company's voluntary worldwide
withdrawal of VIOXX. The unfavorable impact includes estimated customer returns
of product previously sold, write-offs of inventory held by Merck and costs to
undertake the withdrawal of the product. Net income was $1,325.6 million,
including a $552.6 million unfavorable effect related to the withdrawal of
VIOXX. Worldwide sales were $5.5 billion for the quarter, including a $491.6
million unfavorable effect related to the withdrawal of VIOXX.

For the first nine months of 2004, earnings per share were $2.11, net
income was $4,712.3 million and sales were $17.2 billion for the period. These
amounts include the unfavorable effects described above associated with the
withdrawal of VIOXX. Global sales performance includes a 2-point and 3-point
favorable effect from foreign exchange for the third quarter and first nine
months, respectively.

"The voluntary withdrawal of VIOXX, with sales of $2.5 billion last
year, represents a significant financial loss for us, but clearly was the right
course of action," said Merck Chairman, President and Chief Executive Officer
Raymond V. Gilmartin. Merck is redeploying research and development and
marketing and sales personnel formerly dedicated to VIOXX to areas

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where additional growth opportunities exist, including other research programs,
support of in-line products and upcoming product launches. "We look to the
strong launch of VYTORIN and the five Phase III compounds that we expect to file
or launch by the end of 2006 to contribute to the company's future growth,"
added Mr. Gilmartin.

In addition, the company will continue to drive down its cost structure
through a number of initiatives already under way. In October 2003, Merck
announced plans to eliminate 4,400 positions by the end of 2004. As of Sept. 30,
approximately 4,500 positions had been eliminated, as the company identified
additional opportunities to eliminate positions and reduce costs. Beginning in
2005, this action is expected to lower the company's annual payroll and benefit
costs by approximately $250 to $300 million. "Going forward," Mr. Gilmartin
said, "we will continue to look for additional opportunities to enhance
efficiencies, as well as accelerate growth."

Marketing and administrative expenses increased 20% compared to the
third quarter of 2003, including the effect of $141 million for estimated costs
related to the withdrawal of VIOXX and the impact of $34 million for
restructuring costs related to previously announced position eliminations.
Excluding these effects, marketing and administrative expenses for the third
quarter increased 8% from the third quarter of 2003.

VOLUNTARY WITHDRAWAL OF VIOXX

On Sept. 30, Merck announced a voluntary worldwide withdrawal of VIOXX,
its arthritis and acute pain medication. The company's decision, which was
effective immediately, was based on new three-year data from a prospective,
randomized, placebo-controlled clinical trial, APPROVe (Adenomatous Polyp
Prevention on VIOXX).

The trial, which was stopped, was designed to evaluate the efficacy of
VIOXX 25 mg in preventing the recurrence of colorectal polyps in patients with a
history of colorectal adenomas and to further assess the cardiovascular safety
of VIOXX. In this study, there was an increased relative risk for confirmed
cardiovascular events, such as heart attack and stroke, beginning after 18
months of treatment in the patients taking VIOXX compared to those taking
placebo. The results for the first 18 months of the APPROVe study did not show
any increased risk of confirmed cardiovascular events on VIOXX, and in this
respect, are similar to the results of two placebo-controlled studies described
in the most recent U.S. labeling for VIOXX.

Merck presented data from APPROVe at the American College of
Rheumatology (ACR) Annual Scientific Meeting in San Antonio on Oct. 18. The
company had requested the opportunity to present the data at the ACR meeting.

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The company estimates that there were 105 million U.S. prescriptions
written for VIOXX from May 1999 through August 2004. Based on this estimate, the
company estimates that the number of patients who have taken VIOXX in the United
States since its 1999 launch is approximately 20 million. The number of patients
outside the United States who have taken VIOXX is undetermined at this time.

FOURTH-QUARTER AND FULL-YEAR 2004 EPS GUIDANCE

Merck anticipates fourth-quarter EPS of $0.48 to $0.53, which includes
the impact of approximately $700 to $750 million in foregone sales of VIOXX and
potential additional fourth-quarter costs for the withdrawal of VIOXX. As a
result, Merck anticipates full-year 2004 EPS guidance of $2.59 to $2.64, which
includes the expectation that the impact of the withdrawal will negatively
affect full-year EPS by $0.50 to $0.55. Please see pages 11-12 of this news
release for a breakdown of Merck's full-year 2004 financial guidance.

PIPELINE PROGRESS

Research and development expenses increased 18% during the third
quarter, reflecting Merck's ongoing commitment to both basic and clinical
research, as well as the impact of the company's external collaborations, such
as with DOV Pharmaceutical, Inc. and Nastech Pharmaceutical Company Inc.

PROQUAD, a new childhood vaccine that adds chicken pox to the existing
measles, mumps and rubella vaccine, and muraglitazar, the first-in-class dual
PPAR agonist for the treatment of type II diabetes in which Merck is in
collaboration with Bristol-Myers Squibb, are targeted for submission to the U.S.
Food and Drug Administration (FDA) in the fourth quarter.

As previously announced, Merck intends to submit applications to the
FDA for three investigational vaccines in the second half of 2005. The research
and development programs for these investigational vaccines remain on track. The
three vaccines are: ROTATEQ, a vaccine to protect against rotavirus, a highly
contagious virus that causes gastroenteritis and results in the hospitalization
of nearly 50,000 children under 5 each year in the United States; a vaccine to
reduce the incidence of human papillomavirus (HPV) infection and the associated
development of cervical cancer - the second-leading cause of cancer deaths in
women - and genital warts; and a vaccine to reduce the pain that accompanies
shingles, which afflicts 1 million American adults each year.

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Data from an investigational HPV vaccine studied by Merck will be
presented in November at the Interscience Conference on Antimicrobial Agents and
Chemotherapy (ICAAC). The vaccine used in this study was an investigational
monovalent vaccine intended to prevent infection by HPV type 16; it is a
component of Merck's investigational quadrivalent HPV (types 6, 11, 16, 18) L1
VLP vaccine.

Merck continued to augment its internal research efforts with a
comprehensive licensing and external alliance strategy across the entire
spectrum of collaborations from early research to late-stage compounds, as well
as new technologies and targeted acquisitions. During the first nine months of
2004, Merck executed 41 significant transactions, including research
collaborations, pre-clinical and clinical compounds and technology transactions,
as well as the acquisition of Aton Pharma, Inc. Merck has more than 40
opportunities currently in detailed review. For the full year of 2003, Merck
completed 47 such transactions.

In August, Merck and DOV announced an agreement for the development and
commercialization of DOV's novel triple-uptake inhibitors being developed for
depression and related psychiatric disorders. Merck has licensed exclusive
worldwide rights to DOV 21,947, which is in Phase I, for all therapeutic
indications.

In September, Merck and Nastech announced a global alliance to develop
and commercialize Peptide YY 3-36 Nasal Spray (PYY), Nastech's product for the
treatment of obesity, which is currently in Phase I development. The
investigational PYY 3-36 Nasal Spray is designed to deliver the natural,
appetite-regulating hormone PYY directly to the bloodstream.

PRODUCT PERFORMANCE

Worldwide sales of SINGULAIR, a once-a-day oral medicine indicated for
the treatment of chronic asthma and the relief of symptoms associated with
seasonal allergic rhinitis, reached $626 million in the third quarter, which was
2% higher than the third quarter of 2003. Sales in the third quarter of 2003
were favorably impacted by a $120 million buy-in. U.S. mail-order-adjusted
prescription levels for SINGULAIR increased by approximately 18 percent for the
quarter, as compared to the third quarter of 2003. Sales for the first nine
months were $1.9 billion, a 26% increase over the comparable 2003 period.
SINGULAIR continues to be the second-most-prescribed product in the overall
respiratory market in the United States as patients, physicians and managed care
organizations continue to recognize the value SINGULAIR offers to those who
suffer from asthma or seasonal allergic rhinitis.

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FOSAMAX continued as the most-prescribed medicine worldwide for the
treatment of postmenopausal, male and glucocorticoid-induced osteoporosis.
Global sales were strong, reaching $778 million during the quarter and $2.3
billion for the first nine months, representing growth of 13% and 15% over the
respective periods of 2003. U.S. mail-order-adjusted prescription levels for
FOSAMAX were in line with third-quarter 2003 levels.

Results from the FOSAMAX Actonel Comparison Trial (FACT) were presented
on Oct. 1 at the American Society of Bone Mineral Research meeting. This is the
first head-to-head study comparing FDA-approved once-weekly osteoporosis
treatments in postmenopausal women with osteoporosis conducted in the United
States. FACT showed that FOSAMAX demonstrated significantly greater increases in
bone mineral density (BMD) and reductions in markers of bone-turnover than
Actonel. FOSAMAX increased BMD 62 percent more than Actonel at the hip
trochanter (hip bone), with similar tolerability. BMD is a major determinant of
bone strength. The lower the BMD score the greater the risk of fracture.

Global sales of Merck's antihypertensive medicines, COZAAR and HYZAAR*,
were strong, reaching $706 million for the third quarter and $2.1 billion for
the first nine months, representing growth of 14% and 15% over the respective
periods in 2003. COZAAR is the second-most-frequently prescribed angiotensin II
antagonist (AIIA) in the United States and the largest-selling AIIA in Europe.
U.S. mail-order-adjusted prescription levels for COZAAR and HYZAAR increased by
approximately 4 percent for the quarter, as compared to the third quarter of
2003.

Worldwide sales of ZOCOR, Merck's statin for modifying cholesterol,
were $1.2 billion in the third quarter and $3.9 billion for the first nine
months. Third-quarter ZOCOR performance includes an unfavorable comparison to
2003, which was affected by $110 million of wholesaler buy-in, resulting in a
decline in sales of 13% from the same period in 2003. ZOCOR sales growth for the
first nine months was 2% compared to the first nine months of 2003. U.S.
mail-order-adjusted prescription levels for ZOCOR increased by approximately 2
percent for the quarter, as compared to the third quarter of 2003.

Global sales of Merck's coxib, ARCOXIA, reached $61 million in the
third quarter and $153 million for the first nine months. To date, ARCOXIA has
been launched in 48 countries in Europe, Latin America and Asia. The goal PDUFA
(Prescription Drug User Fee Act) date for the New Drug Application (NDA) for
ARCOXIA is Oct. 30. For standard NDAs filed in 2003, FDA's goal is to review and
act on 90 percent of NDAs within 10 months of filing. Merck cannot speculate on
what action the FDA will take.

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*COZAAR and HYZAAR are registered trademarks of E.I. DuPont de Nemours &
Company, Wilmington, Del.

Sales of Merck's other promoted medicines and vaccines were $1.4
billion during the third quarter and $3.8 billion for the first nine months,
representing 5% growth over each of the respective periods of 2003. These
products treat or prevent a broad range of conditions, such as infectious
disease, glaucoma, benign prostate enlargement and migraine.

In support of the call to action issued on Oct. 19 by the U.S. Dept. of
Health and Human Services that emphasizes the importance of pneumococcal
vaccine, Merck is increasing its available supply of Pneumovax 23. Typically,
Merck sells 6 to 7 million doses in the United States annually. The company is
increasing its supply of Pneumovax 23 by 11 million doses.

Global sales of ZETIA (branded EZETROL outside of the United States),
the cholesterol-absorption inhibitor developed and marketed by Merck and
Schering-Plough, reached $293 million in the third quarter and $725 million for
the first nine months. U.S. prescription levels for ZETIA increased by
approximately 70 percent for the quarter, as compared to the third quarter of
2003. In September, ZETIA accounted for approximately 6 percent of total
prescriptions in the lipid-lowering market** and is now reimbursed for nearly 90
percent of all patients in managed care plans in the United States. To date,
EZETROL has been launched in more than 40 countries outside of the United States
and continues to show solid incremental growth. Worldwide sales of ZETIA have
exceeded $1 billion since its 2002 launch.

VYTORIN (marketed as INEGY in many countries outside of the United
States), developed and marketed by Merck and Schering-Plough, was approved by
the FDA on July 23, and has been recently launched in the United States. In the
12 weeks since the product was approved in the U.S., VYTORIN has already
accounted for nearly 2 percent of new prescriptions in the U.S. lipid-lowering
market***. Worldwide sales of VYTORIN were $52 million for the third quarter.

In addition to the United States, VYTORIN has now been approved in 10
countries, including Argentina, Brazil, Germany and Mexico. VYTORIN is
performing well in all markets.

VYTORIN is the first single tablet to provide powerful LDL cholesterol
reduction through dual inhibition of the two sources of cholesterol by
inhibiting the production of cholesterol in the liver and blocking absorption of
cholesterol in the intestine, including cholesterol from food. In two separate
clinical trials, VYTORIN provided greater reductions in LDL cholesterol than
Lipitor or Zocor across the dosing ranges.

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** Source: IMS NPA Plus Monthly Data
***Source: IMS NPA Plus 7 Weekly Data, week ended Oct. 8

VIOXX LITIGATION

As previously disclosed, federal and state personal injury lawsuits
involving individual claims, as well as several putative class actions have been
filed against the company with respect to VIOXX. As of Oct. 15, the company has
been served or is aware that it has been named as a defendant in approximately
300 lawsuits, which include approximately 900 plaintiff groups alleging personal
injuries resulting from the use of VIOXX. Certain of these lawsuits include
allegations regarding gastrointestinal bleeding, cardiovascular events and
kidney damage. The company has also been named as a defendant in several
putative class actions seeking medical monitoring as a result of the putative
class members' use of VIOXX. In addition, certain state court actions seek
various remedies under state consumer fraud and fair business practice statutes,
including recovering the cost of VIOXX purchased by individuals and third-party
payors such as union health plans (all of the actions discussed in this
paragraph are collectively referred to as the "VIOXX Personal Injury Lawsuits").
The actions filed in the state courts of California and New Jersey,
respectively, have been transferred to a single judge in each state for
coordinated proceedings. In addition, the Company expects to file a motion with
the Judicial Panel on Multidistrict Litigation to transfer to a single federal
judge and consolidate for pretrial purposes all federal cases of a similar
nature alleging personal injury and/or economic loss relating to the purchase or
use of VIOXX; several plaintiffs in certain VIOXX Personal Injury Lawsuits
pending in federal court have made similar requests.

As previously disclosed, in addition to the VIOXX Personal Injury
Lawsuits, a number of purported class action lawsuits also were filed in the
third quarter of 2003 and the first quarter of 2004 by several individual
shareholders in the United States District Court for the Eastern District of
Louisiana naming as defendants the company and several current or former
officers of the company, and alleging that the defendants made false and
misleading statements regarding VIOXX in violation of the federal securities
laws (the "VIOXX Securities Lawsuits"). The plaintiffs request certification of
a class of purchasers of the company's common stock between May 22, 1999 and
Oct. 22, 2003, and seek unspecified compensatory damages and the costs of suit,
including attorney fees. After the announcement of the withdrawal of VIOXX, the
company was named as a defendant in three additional purported securities class
action lawsuits filed in federal courts in New Jersey and Pennsylvania. These
later-filed actions request certification of a class of purchasers of company
stock during various periods between Sept. 23, 2003 and Sept. 30, 2004. The
allegations in the later-filed actions are similar to those in the earlier-filed
actions, except that the later-filed actions also contain allegations relating
to

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the withdrawal of VIOXX from the market. The company has been advised by the
attorneys for the plaintiffs that the complaint on the earlier-filed
consolidated actions will be amended to include allegations regarding the
withdrawal of VIOXX and to extend the purported class period until Sept. 30,
2004.

As previously disclosed, in March 2004, two shareholder derivative
actions (the "VIOXX Derivative Lawsuits") were filed in the United States
District Court for the Eastern District of Louisiana naming the company and
certain members of the Board (past and present), together with certain executive
officers, as defendants. The complaints arise out of substantially the same
factual allegations that are made in the VIOXX-related federal securities
putative class actions filed against the company, which principally allege that
the company made false and misleading statements regarding VIOXX. The derivative
suits, which are purportedly brought to assert rights of the company, assert
claims against the Board members and officers for breach of fiduciary duty,
waste of corporate assets and unjust enrichment. The court in the Eastern
District of Louisiana has consolidated the shareholder derivative actions with
the earlier-filed consolidated securities actions.

In addition to these shareholder actions, since the announcement of the
withdrawal of VIOXX, four putative class actions have been filed against the
company, two in the United States District Court for the Eastern District of
Louisiana and two in the United States District Court for the District of New
Jersey (the "VIOXX ERISA Lawsuits" and, together with the VIOXX Securities
Lawsuits and the VIOXX Derivative Lawsuits, the "VIOXX Shareholder Lawsuits") on
behalf of certain of the company's current and former employees who are
participants in certain of the company's retirement plans asserting claims under
the Employee Retirement Income Security Act ("ERISA"). The lawsuits make similar
allegations to the allegations contained in the shareholder lawsuits described
above.

In addition to the lawsuits discussed above, the company has been named
as a defendant in actions in various countries in Europe, Canada, Brazil and
Israel related to VIOXX.

The company has product liability insurance for claims brought in the
VIOXX Personal Injury Lawsuits of up to approximately $630 million after
deductibles and co-insurance. This insurance provides coverage for legal defense
costs and potential damage amounts that have been or will be incurred in
connection with the VIOXX Personal Injury Lawsuits. The company believes that
this insurance coverage extends to additional VIOXX Personal Injury Lawsuits
that may be filed in the future. Certain of the company's insurers have reserved
their rights to take a contrary position with respect to certain coverage and
there could be disputes with insurers

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about coverage matters. The company also has additional insurance with respect
to the VIOXX Shareholder Lawsuits which it believes will apply to cover defense
costs and losses, if any.

The company is unable at this time to determine whether the company's
insurance coverage with respect to the VIOXX Personal Injury Lawsuits and the
VIOXX Shareholder Lawsuits (collectively, the "VIOXX Lawsuits") will be adequate
to cover its defense costs and losses, if any.

Based on media reports and other sources, the company anticipates that
additional VIOXX Lawsuits will be filed against it and/or certain of its current
and former officers and directors in the future.

The company currently anticipates that one or more of the VIOXX
Personal Injury Lawsuits may go to trial in the first half of 2005. The company
cannot predict the timing of any trials with respect to the VIOXX Shareholder
Lawsuits. The company believes that it has meritorious defenses to the VIOXX
Lawsuits and will vigorously defend against them. In view of the inherent
difficulty of predicting the outcome of litigation, particularly where there are
many claimants and the claimants seek indeterminate damages, the company is
unable to predict the outcome of these matters, and at this time cannot
reasonably estimate the possible loss or range of loss with respect to the VIOXX
Lawsuits. The company has not established any reserves for any potential
liability relating to the VIOXX Lawsuits. A series of highly unfavorable
outcomes could have a material adverse effect on the company's financial
position, liquidity and results of operations.

ADDITIONAL THIRD-QUARTER ACTIVITY

On Aug. 20, the U.S. District Court for the District of New Jersey
granted a motion by Merck, Medco Health Solutions, Inc. and certain officers and
directors to dismiss a shareholder derivative action involving claims related to
Merck's revenue recognition practice for retail co-payments, as well as other
allegations. The plaintiffs have appealed this decision. In addition, plaintiffs
in a related purported class-action suit have appealed the July 6 decision by
the U.S. District Court for the District of New Jersey granting a motion to
dismiss the class-action complaint with prejudice.

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EARNINGS CONFERENCE CALL

Investors are invited to a live Web cast of Merck's third-quarter
earnings conference call today at 9 a.m. ET, by visiting the Newsroom section of
Merck's Web site (www.merck.com/newsroom/webcast). Institutional investors and
analysts can participate in the call by dialing (913) 981-5575. Journalists are
invited to listen by dialing (913) 981-5571. The Web cast will be available for
replay on the Web site until Oct. 28.

ABOUT MERCK

Merck & Co., Inc. is a global research-driven pharmaceutical company.
Merck discovers, develops, manufactures and markets a broad range of innovative
products to improve human and animal health, directly and through its joint
ventures.

FORWARD-LOOKING STATEMENT

This press release, including the financial information that follows,
contains "forward-looking statements" as that term is defined in the Private
Securities Litigation Reform Act of 1995. These statements involve risks and
uncertainties, which may cause results to differ materially from those set forth
in the statements. The forward-looking statements may include statements
regarding product development, product potential or financial performance. No
forward-looking statement can be guaranteed, and actual results may differ
materially from those projected. Merck undertakes no obligation to publicly
update any forward-looking statement, whether as a result of new information,
future events, or otherwise. Forward-looking statements in this press release
should be evaluated together with the many uncertainties that affect Merck's
business, particularly those mentioned in the cautionary statements in Item 1 of
Merck's Form 10-K for the year ended Dec. 31, 2003, and in its periodic reports
on Form 10-Q and Form 8-K (if any) which the company incorporates by reference.

# # #

MERCK FINANCIAL GUIDANCE FOR 2004

Worldwide net sales will be driven by the company's major inline
products, including the impact of new studies and indications. Sales forecasts
for those products for 2004 are as follows:

<Table>
<Caption>
WORLDWIDE
PRODUCT THERAPEUTIC CATEGORY 2004 NET SALES
--------------- ------------------------------------- --------------------

ZOCOR Cholesterol modifying $4.9 to $5.1 billion
FOSAMAX Osteoporosis $3.0 to $3.2 billion
COZAAR/HYZAAR Hypertension $2.7 to $2.9 billion
SINGULAIR Asthma and Seasonal Allergic Rhinitis $2.4 to $2.7 billion
</Table>

o Under an agreement with AstraZeneca (AZN), Merck receives revenue at
predetermined rates on the U.S. sales of certain products by AZN, most
notably PRILOSEC and NEXIUM. In 2004, Merck anticipates these revenues to
be approximately $1.4 to $1.6 billion.

o The income contribution related to the Merck and Schering-Plough
collaboration is expected to be positive in 2004. Equity Income from
Affiliates includes the results of the Merck and Schering-Plough
collaboration combined with the results of Merck's other joint venture
relationships. Equity Income from Affiliates is expected to be
approximately $900 million to $1.0 billion for 2004.

o Merck continues to expect that manufacturing productivity will offset
inflation on product costs.

o Product gross margin percentage is estimated to be approximately 74.5% to
75.5% for the fourth quarter of 2004 and 78% to 79% for the full year 2004
as a result of changes to the sales mix. This guidance excludes adjustments
related to the withdrawal of VIOXX.

o Research and Development expense (which excludes joint ventures) is
anticipated to increase at a high-teens percentage growth rate over the
full-year 2003 level. This guidance includes acquired R&D expenses in 2003
and 2004.

o Consolidated Marketing and Administrative expense is estimated to be at the
same level as the full-year 2003 expense. This guidance excludes
restructuring costs in 2003 and 2004 and excludes adjustments related to
the withdrawal of VIOXX.

o The consolidated 2004 tax rate is estimated to be approximately 28 to 29%.
This guidance excludes adjustments related to the withdrawal of VIOXX.

o Merck plans to continue its stock buyback program in 2004. As of Sept. 30,
$8.8 billion remains under the current buyback authorizations approved by
Merck's Board of Directors.

o Approximately 4,500 positions had been eliminated as of Sept. 30, as the
company identified additional opportunities to eliminate positions and
reduce costs. This program, which was announced in October 2003, will be
completed by the end of 2004. Restructuring costs for full-year 2004 are
expected to be approximately $90 to $95 million.

Given these guidance elements, Merck anticipates fourth-quarter EPS of
$0.48 to $0.53, which includes the impact of approximately $700 to $750 million
in foregone sales of VIOXX and potential additional fourth-quarter costs for the
withdrawal of VIOXX. As a result, Merck anticipates full-year 2004 EPS guidance
of $2.59 to $2.64, which includes the expectation that the impact of the
withdrawal will negatively affect full-year EPS by $0.50 to $0.55.

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ABOUT MERCK

FORWARD-LOOKING STATEMENT

# # #

The following table shows the financial results for Merck & Co., Inc. and
subsidiaries for the quarter ended Sept. 30, 2004, compared with the
corresponding period of the prior year.

<Table>
<Caption>
Merck & Co., Inc.
Consolidated Results
(In Millions Except Earnings per Common Share)
Quarter Ended Sept. 30
---------------------------------------------
%
2004 2003 Change
---------- ----------- --------

Sales $ 5,538.1 $ 5,762.0 -4%

Costs, Expenses and Other
Materials and production 1,364.2 1,083.4 26
Marketing and administrative (1) 1,752.9 1,463.6 20
Research and development (2) 919.3 776.5 18
Equity income from affiliates (307.1) (183.4) 67
Other (income) expense, net (4.2) 17.1 *

Income from Continuing Operations
Before Taxes ** 1,813.0 2,604.8 -30

Taxes on Income (3) 487.4 739.8

Income from Continuing Operations ** $1,325.6 $ 1,865.0 -29

Income from Discontinued Operations, Net of Taxes -- (6.7)

Net Income $1,325.6 $ 1,858.3 N/M

Average Shares Outstanding
Assuming Dilution 2,226.2 2,253.9

Earnings per Common Share
Assuming Dilution
Continuing Operations ** $0.60 $0.83 -28
Discontinued Operations -- (0.00)
----- ------
Total $0.60 $0.82(4) N/M
</Table>

* > 100%

** Continuing operations exclude only the results from Medco Health Solutions,
Inc., which was spun off on Aug. 19, 2003

N/M Comparison not meaningful as a result of the spin-off of Medco Health.

(1) 2004 Marketing and administrative expense includes $34 million for
restructuring costs.

(2) Research and development expense includes licensing expense for research
collaborations, including the initial payment of $35 million to DOV
Pharmaceutical in the third quarter of 2004.

(3) The effective tax rate was 26.9% and 28.4% for the third quarter of 2004 and
2003, respectively.

(4) Amount does not add as a result of rounding.

The following table shows the financial results for Merck & Co., Inc. and
subsidiaries for the quarter ended Sept. 30, 2004 and the line item effect of
adjustments related to the worldwide voluntary withdrawal of VIOXX included in
the financial results. The adjustments include estimated customer returns of
product previously sold, write-offs of inventory held by Merck and costs to
undertake the withdrawal of the product.

<Table>
<Caption>
Merck & Co., Inc.
Consolidated Results
(In Millions Except
Earnings per Common Share)
Quarter Ended Sept. 30
------------------------------------
2004
(Including
VIOXX VIOXX
Withdrawal Withdrawal
Impact) Impact
--------------- ----------------

Sales $ 5,538.1 ($491.6)

Costs, Expenses and Other
Materials and production 1,364.2 93.2
Marketing and administrative 1,752.9 141.4
Research and development 919.3
Equity income from affiliates (307.1)
Other (income) expense, net (4.2)

Income from Continuing Operations
Before Taxes 1,813.0 (726.2)

Taxes on Income 487.4 (173.6)

Net Income $ 1,325.6 ($552.6)

Average Shares Outstanding
Assuming Dilution 2,226.2

Earnings per Common Share
Assuming Dilution $0.60 ($0.25)
</Table>

The following table shows the financial results for Merck & Co., Inc. and
subsidiaries for the nine months ended Sept. 30, 2004 compared with the
corresponding period of the prior year.

<Table>
<Caption>
Merck & Co., Inc.
Consolidated Results
(In Millions Except Earnings per Common Share)
Nine Months Ended Sept. 30
---------------------------------------------
%
2004 2003 Change
---------- ----------- --------

Sales $ 17,190.7 $ 16,858.8 2%

Costs, Expenses and Other
Materials and production 3,676.2 3,209.7 15
Marketing and administrative (1) 4,980.5 4,567.5 9
Research and development (2) 2,901.6 2,373.6 22
Equity income from affiliates (722.3) (468.2) 54
Other (income) expense, net (240.0) (114.5) *

Income from Continuing Operations
Before Taxes ** 6,594.7 7,290.7 -10

Taxes on Income (3) 1,882.4 2,096.3

Income from Continuing Operations ** $ 4,712.3 $ 5,194.4 -9

Income from Discontinued Operations, Net of Taxes -- 241.3

Net Income $ 4,712.3 $ 5,435.7 N/M

Average Shares Outstanding
Assuming Dilution 2,229.5 2,258.9

Earnings per Common Share
Assuming Dilution
Continuing Operations ** $ 2.11 $ 2.30 -8
Discontinued Operations -- 0.11
----- -----
Total $ 2.11 $ 2.41 N/M
</Table>

* > 100%

** Continuing operations exclude only the results from Medco Health Solutions,
Inc., which was spun off on Aug. 19, 2003.

N/M Comparison not meaningful as a result of the spin-off of Medco Health.

(1) 2004 Marketing and administrative expense includes $90 million for
restructuring costs.

(2) Research and development expense includes acquired research expense of $125
million resulting from the acquisition of Aton Pharma, Inc. in 2004 and $90
million associated with the increase in ownership of Banyu Pharmaceutical Co.
Ltd. in 2003. Research and development expense also includes licensing expense
for research collaborations, including the initial payments of $70 million to
Lundbeck in the first quarter of 2004, $100 million to Bristol-Myers Squibb and
$20 million to Vertex in the second quarter of 2004, and $35 million to DOV
Pharmaceutical in the third quarter of 2004.

(3) The effective tax rate was 28.5% and 28.8% for the first nine months of 2004
and 2003, respectively.

The following table shows the financial results for Merck & Co., Inc. and
subsidiaries for the nine months ended Sept. 30, 2004 and the line item effect
of adjustments related to the worldwide voluntary withdrawal of VIOXX included
in the financial results. The adjustments include estimated customer returns of
product previously sold, write-offs of inventory held by Merck and costs to
undertake the withdrawal of the product.

<Table>
<Caption>
Merck & Co., Inc.
Consolidated Results
(In Millions Except
Earnings per Common Share)
Nine Months Ended Sept. 30
------------------------------------
2004
(Including
VIOXX VIOXX
Withdrawal Withdrawal
Impact) Impact
--------------- ----------------

Sales $ 17,190.7 ($491.6)

Costs, Expenses and Other
Materials and production 3,676.2 93.2
Marketing and administrative 4,980.5 141.4
Research and development 2,901.6
Equity income from affiliates (722.3)
Other (income) expense, net (240.0)

Income from Continuing Operations
Before Taxes 6,594.7 (726.2)

Taxes on Income 1,882.4 (173.6)

Net Income $ 4,712.3 ($552.6)

Average Shares Outstanding
Assuming Dilution 2,229.5

Earnings per Common Share
Assuming Dilution $2.11 ($0.25)
</Table>

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