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An article in the December 19, 2001, online issue of WebMD, reporting on a study from the December 20, 2001, New England Journal of Medicine, highlights that two of the most common over-the-counter drugs can have serious effects. The study, conducted in Sweden, involved interviewing 1,924 subjects, half of whom had been recently diagnosed with renal (kidney) failure. In the group with renal failure, the usage of aspirin and Tylenol was 37% and 25%, respectively. In the control group, the usage of aspirin and Tylenol was considerably lower, with rates of 19% and 12%, respectively. These results clearly showed a higher rate of long-term usage of these drugs in the patients who eventually suffered renal failure.

Michael Fored, MD, author of the study and a kidney specialist at the Karolinska Institute in Stockholm, Sweden, stated, “What we have seen is that there is an association between acetaminophen [the generic name for Tylenol] and aspirin and chronic [kidney] failure. Our results are consistent with the existence of exacerbating effects of acetaminophen and aspirin on chronic renal failure.”

The WebMD story noted that taking either of the two drugs increased the risk of kidney failure for people with kidney disease. The article further pointed out that taking just one of the drugs increased this risk 2.5-fold, and taking more of each drug over the course of a lifetime greatly increased the risk. The cumulative (lifetime) risk increased faster with Tylenol than with aspirin. A lifetime dose of at least 500 grams increased the risk of kidney failure 3.3-fold. “This is not that high a dose,” Fored says. “For the usual 500 mg pill, that is 1,000 tablets. That is three tablets a day for a year. It is not that high a dose for a person with chronic pain.”

The very next article published in the same December 20, 2001, issue of the New England Journal of Medicine reports on a study showing that taking ibuprofen (Advil or Motrin) almost totally wipes out any positive heart effects that taking aspirin was hoping to cause. In this report, Dr. Muredach Reilly, a University of Pennsylvania cardiologist who took part in the 30-patient study, noted that when patients took a single dose of ibuprofen beforehand, aspirin lost 98% of its blood-thinning power. When aspirin was taken first, three daily doses of ibuprofen sapped aspirin of 90% of its benefit. He concluded, “It would not do you a lot of good to take one medication only to have another wipe out its effects.”