Drug Firms Set Up Major Marketing Unit : Pharmaceuticals: Deals with Wellcome and Glaxo Holdings will make Warner-Lambert an over-the-counter powerhouse.

Warner-Lambert Co. on Wednesday announced agreements with two other drug makers that will make it a powerhouse in over-the-counter health care products, an arena that is becoming increasingly important in the face of health care reform and mounting pressures on prescription drug prices.

The Morris Plains, N.J., company said it is forming a joint venture with Britain’s Wellcome for worldwide marketing of Warner’s substantial line of consumer products--including such well-known brands as Listerine and Benadryl--as well as future non-prescription versions of both companies’ drugs. These will include the jewel of Wellcome’s line, Zovirax, an antiviral prescription drug that chalked up sales of $1.2 billion last year.

In a separate agreement, Warner-Lambert said it will also sell over-the-counter versions of pharmaceuticals made by London-based Glaxo Holdings, including Zantac, the ulcer medication that now is the biggest-selling prescription drug in the world, with 1992 sales of $3.2 billion.

The agreements position the companies to compete in the growing over-the-counter arena, a marketplace attracting drug makers whose profits are being hemmed in by generics on the one side and, on the other, pressure from the government and health insurance providers to control prescription drug prices.

By converting prescription drugs to over-the-counter products, the companies also continue revenue streams from older products that, upon losing patent protection, will face stiff competition from generic (or unbranded) versions.

It also is part and parcel of the changes in the drug industry, as pharmaceutical companies align themselves with partners of different strengths to improve their competitive positions.

“It’s a very logical marriage of strengths between these companies,” said Steven B. Gerber, a securities analyst with Oppenheimer & Co. in Los Angeles.

Gerber said that while Warner-Lambert is strong in over-the-counter and consumer product sales, it is not particularly strong in prescription drug sales, nor does it have strength in research and development. The two British companies, on the other hand, are weak in consumer products marketing but strong in prescription-drug sales and in moving promising products through research and development.

A spokeswoman for Warner-Lambert said the companies hope to get federal regulatory clearance to convert both Zantac and Zovirax to over-the-counter status before their patents expire--that is, before generic-drug makers can enter the competition.

Zovirax, used to treat genital herpes, will lose patent protection in 1997 and Zantac’s patent will expire in 2002. A request for over-the-counter status for Zovirax is expected to be filed with the federal Food and Drug Administration next month.

* DRUG DEAL: Drug giant Merck will pay $6 billion to acquire a leading pharmaceutical distributor. A1