BOSTON, MASSACHUSETTS. Over $2 billion is spent every year on the purchase of over-the-counter painkillers (analgesics) such as aspirin, ibuprofen (a NSAID or nonsteroidal anti-inflammatory drug) and acetaminophen (Tylenol or Paracetamol). Little is known about the possible association between analgesics and hypertension (high blood pressure), but it is conceivable that they may interfere with blood pressure regulation by decreasing sodium excretion, inhibiting nitric oxide synthesis or by altering the production of vasodilatory prostaglandins.
Researchers at Harvard Medical School have just completed a major study involving over 80,000 female
nurses between the ages of 31 and 50 years and with no diagnosed hypertension at the beginning of the
study. The nurses kept track of their use of analgesics for a 2-year period thus resulting in 164,090 person-
years of follow-up. During the follow-up 1650 cases of hypertension were identified giving an annual
incidence rate of 1%. Nurses who took NSAIDs for 22 days a month or more were found to have an 86%
increased rate of developing hypertension (absolute annual risk of 1.86%) while nurses who used
acetaminophen for 22 days a month or more doubled their risk to an absolute 2% per year. The risk
increase for acetaminophen was dose-dependent and using it as little as 1-4 days per month increased the
relative risk by 22%. Aspirin usage 1-4 days a month increased relative risk by 18%, but this risk was no
longer statistically significant after adjusting for other known risk factors like smoking and a family history of
hypertension. The researchers conclude that a substantial proportion of hypertension in the United States
may be due to the use of analgesics on a regular basis.