Drugs: The Dangers of Analgesics

The benefits of such over-the-counter pain relievers as aspirin and APCs have long been recognized. But evidence that these familiar remedies are not necessarily harmless in all circumstances has accumulated only recently. For reasons not yet understood, people who take excessive doses over a number of years may incur anemia or kidney damage.

Warning Required. First of the currently popular analgesics to be questioned was phenacetin, the “P” in APC tablets (aspirin, phenacetin, caffeine). Medical centers in Europe reported that patients who had regularly taken large quantities of painkillers containing phenacetin had suffered kidney damage, and there had been a number of deaths. In 1964, the U.S. Food and Drug Administration required a notice on the labels of remedies containing phenacetin: “Warning — this medication may damage the kidneys when used inlarge amounts or for a long period of time.”

Then Dr. Laurence F. Prescott, who was doing clinical investigation at Johns Hopkins University, tested four ingredients in widely used analgesics, alone and in combination. He reported in The Lancet that healthy volunteers who took ten aspirin tablets a day began to excrete damaged kidney cells, reflecting at least temporary kidney injury. Surprisingly, this effect was less marked with APCs. It was also less conspicuous when he tested phenacetin alone, and still less so with medicinal caffeine.

Dr. Prescott’s conclusion: phenacetin alone is not the primary villain in analgesic kidney damage. Back in his native Britain, he found that some of the supposedly phlegmatic Scots of the Grampian Hills were taking analgesic powders and tablets in overdoses that ran as high as ten tablets a day for 14 years. In a two-year period, 36 patients appeared at Aberdeen Royal Infirmary with kidney disease and “a history of long-continued and excessive intake of analgesics.” Besides their kidney damage, 30 of the patients were suffering from anemia, six had peptic ulcers and twelve had suffered gastrointestinal bleeding.

Internal Bleeding. Ulcer patients have long been known to be susceptible to internal bleeding after taking aspirin, but this was assumed to result from what was, in effect, an overdose only for their sensitive stomachs. Not necessarily, two researchers now report in the British Medical Journal. Dr. Desmond Croft and Dr. Philip H. N. Wood gave ordinary doses—the equivalent of twelve aspirins a day for one to four weeks—to 226 people who had no ulcers or any other “stomach trouble.” All but nine suffered at least minor bleeding from their stomach walls into the intestines, and in 150 it was substantial. In The Netherlands, three doctors have just reported five cases of generalized anemia (deficiency of red and white cells and of platelets) that they attribute to aspirin consumed to excess.

None of this means that analgesics in normal doses are dangerous; they are probably safer than most other non-prescription drugs. But there may be a limit. The expert consensus so far: when doctors prescribe ten or twelve five-grain aspirins a day for persistent painful disorders such as arthritis, they should watch their patients closely for signs of anemia or kidney damage. And headache victims who become aspirin or APC addicts should invest in a visit to the doctor. It may be cheaper in the long run.