The Food and Drug Administration is getting ready to ban phenacetin, one of the most swallowed pain killers of modern times.

The ban may not take effect for a year or so, but drug-makers, moved by reports of kidney damage and possible cancer after long use and by the threat of FDA action, started removing the chemical two years ago. They have been doing so increasingly in the past few months.

This means that such familiar products as Anacin, Excedrin, Bromo-Seltzer, Super-Anahist, Empirin and APC's (for "aspirin, phenacetin and caffeine") either no longer contain phenacetin or will soon be without it.

Two well-known products that do contain it are Darvon Compound and Darvon Compound 65. Other forms of Darvon don't have it, said their manufacturer, Eli Lilly and Co.

A formal FDA proposal to remove the drug from both over-the-counter and prescription products is to be published early this fall, FDA sources said yesterday. Then it could take a year, they said, to get public and industry comment and implement the ban.

Meanwhile, a Pharmaceutical Manufacturers Association (PMA) spokesman said many firms have substituted acetaminophen, an increasingly used painkiller in Tylenol and many other pills.

Some have substituted nothing. The formula for Anacin, for example, is now just aspirin and caffeine, mainly aspirin, according to the latest Handbook of Nonprescription Drugs.

"But many substitutions have been made only recently or are just being planned, so a lot of the phenacetin products are still on the shelves," said another industry official. "If you're concerned, you'll just have to read the labels for a while."

The FDA said some small manufacturers of generic products -- those without brand names -- may still be making APC's with phenacetin. APC's have been dispensed by the millions as cold pills or pain pills in military and industrial clinics.

The PMA, after a survey of reference works and its members, said all but four indicate that phenacetin is out or on the way out.The four are Eli Lilly, Wallace Laboratories (Soma), Sandoz Pharmaceuticals (Florinal) and Smithkline Corp. (SK-65).

Smithkline said it is considering removal of phenacetin. The PMA represents only prescription drug-makers.

Doctors began associating heavy phenacetin use with occasional kidney damage some years ago. Thirteen patients in every 100 admitted to one large kidney-failure clinic have had damage linked to analgesic abuse, and the main analgesic used has been phenacetin, according to the current Annals of Internal Medicine.

In the same report, four Bowman-Gary Medical School doctors described the link between heavy phenacetin use and urinary tract cancer. Of 115 urinary cancer patients at their hospital over a three-year period, six were heavy users of analgesics, mainly phenacetin.

Most of the affected patients were young or middle-aged women with tumors of the pelvis.

"By heavy or excess use," said Dr. Vardaman Buckalew Jr., one author of the Annals report, "We mean taking four to six tablets a day for three years or more. Anyone who takes that much risks kidney disease and possibly cancer.

"That may sound like a lot of pills, but we see many such chronic users. People in this part of the country have been taking headache powders with phenacetin for years. I think it goes back to the days when people in the cotton and textile mills had lots of headaches, and the mills used to give these powders away.

"It's still quite possible to buy phenacetin products under many names," he added. Even if phenacetin is removed from pain-relief preparations, he said, "people who have used it heavily ought to watch themselves and see a doctor if they have any odd symptoms."

The same advice goes for those who used another suspect drug for several years, Dr. William Lijinsky of the Frederick, Md., Cancer Research Center said yesterday.

This is methapyrilene, an antihistamine that was long an ingredient of sleep aids like Sominex, Nytol, Compoz, Cope and Exedrin P.M. Lijinsky said in the journal Science that there is strong evidence that methapyrilene, no longer used in the sleep aids, is a powerful cause of cancer in animals.