Study finds acetaminophen increases blood pressure in patients with coronary artery disease

The commonly used pain reliever-acetaminophen-causes a significant increase in blood pressure in patients with pre-existing coronary artery disease (CAD), according to a randomized controlled trial published ahead of print in the October 18, 2010, Circulation.

Traditional nonsteroidal anti-inflammatory drugs have been associated with increased risk for acute cardiovascular events. Consequently, current treatment guidelines recommend acetaminophen as the first-line analgesic of choice on the assumption of its greater cardiovascular safety. "This study demonstrates for the first time a significant increase in ambulatory blood pressure in patients with CAD treated with acetaminophen," the researchers emphasized. "Thus, the use of acetaminophen should be evaluated as rigorously as traditional nonsteroidal anti-inflammatory drugs and cyclooxygenase-2 (COX-2) inhibitors, particularly in patients at increased cardiovascular risk."

In this trial, researchers randomly administered acetaminophen at a dose of 1 g 3 times daily followed by matching placebo, or the reverse, to 33 patients with CAD as part of a cross-over trial. All patients received each therapy for a 2-week period and remained on their standard of care cardiovascular drugs. The study demonstrated that acetaminophen resulted in a significant increase in mean systolic (from 122.4 ± 11.9 to 125.3 ± 12.0 mmHg, P=.02 versus placebo) and diastolic (from 73.2 ± 6.9 to 75.4 ± 7.9 mmHg, P=.02 versus placebo) blood pressures. Acetaminophen was not found to significantly affect other cardiovascular safety markers including heart rate, platelet, or endothelial cell function (P>.05 for all).

William B. White, MD, a hypertension expert from the University of Connecticut School of Medicine, concurred with the researchers' conclusions, stressing, "Despite broad recommendations to use acetaminophen as first-line therapy for pain and arthritis in patients with heart and vascular disease, the agent is simply not that effective, and as supported by new findings by Sudano et al, a lot more is unknown about this drug from a cardiovascular safety perspective than we know about the conventional NSAIDs and selective COX-2 inhibitors."

The researchers conclude their paper by noting that acetaminophen's highly prevalent use and the blood pressure increases observed in their study suggest "a major public health concern."

SOURCES

Sudano I, Flammer AJ, Périat D, et al. Acetaminophen increases blood pressure in patients with coronary artery disease. Circulation. 2010;Oct 18. [Epub ahead of print]

White WB, Campbell P. Blood pressure destabilization on nonsteroidal antiinflammatory agents: acetaminophen exposed? Circulation. 2010;Oct 18. [Epub ahead of print]