ONE OF THE MOST POPULAR drugs being used as a painkiller is Darvon. Yet its effectiveness in easing pain has been seriously challenged, and its widespread abuse has been linked to a disturbing number of deaths in this country. Last year, according to the Justice Department's Drug Abuse Warning Network, 589 deaths were related to the use of Darvon, which is chemically similar to methadone and which in overdoses can cause coma or death. Yet in the same year, doctors wrote 35.5 million prescriptions for this drug, which its manufacturer, Eli Lilly & Company, defends as having "as long history of safe and effective use." So who's right on this matter? How freely should Darvon be dispensed?

Dr. Sidney M. Wolfe, director of Ralph Nader's Health Research Group, is urging the government either to ban Darvon or to limit its production and prohibit prescription refills. In a letter to HEW Secretary Joseph A. Califano, Dr. Wolfe notes that studies have shown the drug to be no more effective than aspirin as a painkiller. Besides, he says, other "cheaper more effective and less dangerous" drugs could easily be substituted for it.

The government has recognized some need to restrict Darvon. In 1973, the Drug Enforcement Administration first urged strict controls on the drug. By 1976, a Food and Drug Administration advisory committee recommended requirements that druggists refill a Darvon prescription no more than five times in six months and that records be kept of sales and production. That regulation went into effect last year. But clearly, even while many doctors and patients seem content with Darvon, its heavy use is still leading to unnecessary, lethal abuses - rivaling the number of deaths caused by heroin.

Now that suggests to us a simple conclusion: While a legal ban on the drug may not be in order, if Darvon isn't all that effective as a painkiller, it makes no sense to permit such widespread use. Mr. Califano has referred the matter to the FDA and has asked for rapid review and recommendations. We trust that his request will lead to much stricter controls on Darvon's use - and abuse.