Merck & Co. (MRK) 8-K Regulation FD Disclosure

Exhibit 99.1

	July 17, 2008 — Frequently Asked Questions and Answers — (FAQ’s)
	From time to time, Investor Relations will provide FAQs on various topics of interest.
Q	What are the IMS prescription volumes for VYTORIN and ZETIA?
A	U.S. Total Prescription Volume (000’s)

	January		February		March		April		May		June
	2008		2008		2008		2008		2008		2008
Cholesterol Management Market		20,402		18,941		19,687		19,543		19,804		19,398
Total Merck/Schering-Plough Franchise		3,205		2,773		2,803		2,492		2,463		2,352
VYTORIN		1,839		1,597		1,610		1,420		1,404		1,330
ZETIA		1,366		1,176		1,193		1,072		1,060		1,022

Source: IMS’National Prescription Audit Plus (NPA+)as of July 15, 2008, which includes routine refinements by IMS to previously published data.

DISCLOSURE NOTICE: The information in the frequently asked questions included in this FAQ, and in other written and oral statements about Schering-Plough and its business made by Schering-Plough or its officers from time to time, includes certain “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, including statements relating to prescription trends for VYTORIN and ZETIA.

Forward-looking statements relate to expectations or forecasts of future events. Schering-Plough does not assume the obligation to update any forward-looking statement. Many factors could cause actual results to differ materially from Schering-Plough’s forward-looking statements, including market forces (such as customer buying patterns); economic factors; product availability; patent and other intellectual property protection; current and future branded, generic or over-the-counter competition; the timing and outcomes of the regulatory process; and prescriber and patient reaction to data obtained from post-marketing clinical trials and media reaction to such data, among other uncertainties. For further details about these and other factors that may impact the forward-looking statements, see Schering-Plough’s Securities and Exchange Commission filings, including Part II, Item 1A. “Risk Factors” in Schering-Plough’s 2008 10-Q, filed May 6, 2008.

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