Acetaminophen Linked to Hypertension
Frequent Users Are Twice as Likely to Develop High Blood Pressure
Oct. 28, 2002 -- People with high blood pressure may be no better off taking acetaminophen for pain than other analgesics. A new study suggests that the pain reliever may increase the risk of hypertension to an even greater degree than nonsteroidal anti-inflammatory drugs (NSAIDs).
Hypertensive patients with chronic pain are often warned against taking either over-the-counter or prescription NSAIDs because studies have linked them to increases in blood pressure. It has been widely believed that aspirin and acetaminophen do not affect blood pressure, but Harvard University researcher Gary Curhan, MD, ScD, says few studies have tested this.
Traditional NSAIDs include a host of pain relievers like the ibuprofen drugs Motrin, Advil, and Nuprin, and the naproxen drug Aleve. The prescription drugs Vioxx, Celebrex, and Bextra are among a newer class of NSAIDs, known as Cox-2 inhibitors.
In this study, Curhan and colleagues examined the long-term use of acetaminophen, NSAIDs, and aspirin among 80,000 women taking part in an ongoing health study. Their aim was to determine what, if any, association the three commonly used analgesic classes have on blood pressure.
None of the women included in the study had high blood pressure at the start of the study, and all were between the ages of 31 and 50. Roughly 1,600 were diagnosed with hypertension during the following eight years. The findings are reported Oct. 28 in the journal Archives of Internal Medicine.
After adjusting for other risk factors, the study showed that women who took NSAIDs for 22 days or more a month had an 86% increased risk for developing hypertension compared with women who reported taking no analgesics. Those taking the same amount of acetaminophen had double the risk of nonusers. No increased risk was seen in women taking aspirin.
Lesser, but still elevated, increases in risk were seen for women who took acetaminophen or NSAIDs less frequently.
""Even women who took NSAIDs or acetaminophen as infrequently as one to four days per month had an increase in risk,"" Curhan tells WebMD. ""The message here is that these medications, even though they are available over the counter, may have risks associated with them. Aspirin has its own set of well-known risks.""
Rheumatologist C. Kent Kwoh, MD, tells WebMD that the latest findings are of concern because doctors often turn to acetaminophen to treat patients who have chronic pain and high blood pressure.
""These are interested findings, and they definitely need to be followed up to determine if this association is real,"" he says. ""There is not enough evidence at this point to tell people not to take acetaminophen, but we do need to examine this further.""
Kwoh, who is director of clinical research at The University of Pittsburgh Arthritis Institute, says more studies are needed to better understand how the currently available pain medications affect blood pressure.
Although it has been suggested that the newest Cox-2 inhibitor Bextra may be safer than others for patients with high blood pressure, Kwoh says he knows of no studies comparing the drugs.
""If someone has hypertension, it doesn't necessarily mean they can't take NSAIDs,"" he says. ""But they need to take them under the supervision of a physician and monitor their blood pressure carefully. And if they have pain that is easily managed, they should probably avoid taking NSAIDs.""