The Food and Drug Administration is drafting a proposal to halt sales of two medicines widely prescribed for certain blood vessel diseases because of a lack of evidence that the medicines work.

The medicines, papaverine and ethaverine, are ingredients of 55 trade-named products, and are "clearly dangerous" as well as "ineffective," according to "Pills That Don't Work," a newly published book.

The authors, Dr. Sidney M. Wolfe and Christopher M. Coley of the Washington-based, nonprofit Health Research Group (HRG), said in an interview that the HRG would petition the FDA to take the drugs off the market.

Last year, according to the HRG, physicians wrote 5.2 million prescriptions for the products and consumers paid $47 million to have them filled. Of that total, $31 million went for Marion Laboratories' Pavabid.

The Kansas City, Mo., firm has generated "a lot of pressure" -- in the form of letters to the FDA and Capitol Hill -- against agency action, a source said. The case could provide an early test of the incoming Reagan administration's attitudes toward consumer protection, he added.

An FDA spokesman declined comment beyond recalling the conclusion reached by an advisory panel of outside experts in August 1979: "There is no body of evidence that will support the effectiveness of paperverine and ethaverine for any of their claimed indications [uses]." Asked why no action resulted in the ensuing 15 months, the spokesman said. "The delay has to do with priorities."

An earlier alert to the unproved effectiveness of the medicines was sounded by the American Medical Association in the 1973 edition of its "AMA Drug Evaluations."

A 1962 drug law requiring manufacturers to document claims of effectiveness with substantial scientific evidence contains a "grandfather clause" exempting any medicine identical in composition, dosage form and labeled uses to a drug marketed before 1938.

The FDA has ruled that none of the 55 brand-name products either qualifies for the exemption or was licensed between 1938 and 1962 to be audited for effectiveness. Consequently, according to the book, sale of the drugs "appears to be blatantly illegal."

Not until 1976 did the FDA say that effectiveness claims for the drugs were questionable. In 1979, the agency published findings of a study showing that manufactures had provided no substantial evidence of effectiveness and said it "is not aware of any evidence estabishing the safety of the drugs for their indicated uses."

According to the book, liver damage was found in one in five patients who, in a 1969 study, took a "moderate" (160-milligram) daily dose of papaverine. It is half as potent as its synthetic derivative, ethaverine, commonly sold as Ethanab or Ethaquin.

The book, which describes "610 prescription drugs that lack evidence of effectiveness" for which consumers paid an estimated $1.1 billion in 1979, is available for $6 from "Pills," Department N, 2000 P St. NW, Washington, D.C. 20036.