A new study in the journal Neurology, published by the American Academy of Neurology (AAN) suggests that intravenous (IV) aspirin use in high doses is safe, effective, and useful in managing severe headaches in hospitals. The British-based study focused on the use of IV aspirin for headaches resulting from withdrawal of other medications used to relieve pain, including acetaminophen, opioids, triptans, or serotonin receptor agonists. But its results are sparking interest in the potential use of IV aspirin treatments for severe migraine.
“This has the potential for helping a lot of people,” notes Andrew Hershey, M.D., Ph.D., director of the Headache Center and associate director of research in the division of neurology at Cincinnati Children's Hospital, who was not involved in the study. “It gives us another form of IV treatment for use in emergency rooms and hospitals, and possibly wider use in doctor's offices.”
In the five-year study, researchers looked at 168 patients—117 women and 51 men—who had been hospitalized for migraines or headaches and given aspirin through an IV for 15 days or more a month for three months. Based on interviews with and journals by the patients, 25 percent experienced a major drop in pain levels (3 points on a pain scale of 10), while 40 percent felt a “moderate impact” of one or two points of pain reduction. Approximately six percent suffered minor side effects including nausea, vomiting, and trouble with the insertion of the IV. Two people dropped out of the study, one because of asthma and the other as a result of “needle phobia.”
“The finding of pain improvement on hospital inpatients with headache given IV aspirin is plausible to me, given my own clinical experience,” notes Gretchen E. Tietjen, M.D., chair of the neurology department and director of the Headache Treatment and Research Program at the University of Toledo Medical Center, who was not involved in the study. “However, this study was retrospective, uncontrolled, and confounded by the fact that many patients were prescribed more than one medication. Given the high cost of hospitalization and patient's high expectations for pain relief in this setting, the overall finding of an average 1-point reduction on a 10-point pain scale tempers my enthusiasm.”
Generally, retrospective studies are viewed as less reliable for several reasons. A retrospective study looks backward in time at information that has already been collected, instead of investigating the response of a group of patients to a particular treatment. Many experts believe that retrospective studies provide more opportunities for bias. Also, retrospective studies don't include what is considered a “gold standard” for clinical research: the comparison of a group receiving the experimental therapy versus a control group made up of subjects who receive either a placebo or alternative treatment.
Peter J. Goadsby, M.D., Ph.D., of the Headache Group at the University of California, San Francisco, acknowledges that the study has limitations, but says, “Our findings warrant more research into the use of IV aspirin for severe headache or migraine.”
IV aspirin has not been readily available in the United States to date. The reason? The treatment is not FDA-approved, according to Crystal Rice, media representative at the U.S. Food and Drug Administration's Center for Drug Evaluation and Research.
“The next step would be to work through the FDA approval process,” says Dr. Hershey.
“This study also demonstrates that migraine patients are not looking for sedation or addiction, they're looking for relief,” Dr. Goadsby says. “If you can give them relief without those side effects, they'll be fine.”