麻豆传媒

SCOTTSDALE, Ariz. -- Can medications that relieve acute headache pain paradoxically worsen headache if used too often? And if so, how big of a problem is it?

"It's a hen-and-egg dilemma," said Hans-Christoph Diener, MD, PhD, of the University Essen in Germany, at the ."Does migraine get worse and patients take more medication? Or do patients take more medication and migraine gets worse?"

Medication overuse headache plays a major role in chronic migraine, Diener said during a panel discussion: "What we have learned from epidemiology is that medication overuse headache constitutes between 25% and 50% of all patients with chronic migraine and that about suffers from chronic migraine." Medication overuse carries greater risks than just more headache, he added: patients who overuse opioids are at risk of dependency and addiction.

Clinical studies have outlined the clinical and pharmacological features associated with medication overuse headache, which can vary with the primary headache disorder and the drug used. "We can identify people with to have medication overuse," Diener said.

Treatment is withdrawal and "the majority of patients with medication overuse headache revert to episodic migraine after successful treatment," he added. "But there is a subgroup of patients where you withdraw the medication and the headache doesn't change."

That general perspective is what Elizabeth Loder, MD, MPH, of Harvard Medical School, called the "gospel of medication overuse headache" -- the belief that "medication overuse headache mostly occurs in people with a primary headache disorder; that it is the most common form of secondary headache; and that clinicians have to carefully monitor the use of pain-relieving medication to prevent people who doing okay now from getting worse and having more headache in the future," she said.

"My arguments are not that medication overuse headache does not exist or medication overuse does not contribute to chronic migraine, but that it is over-emphasized and the evidence in support of these concepts is quite weak," Loder stated.

Much of the evidence about medication overuse headache is based on observational studies that are subject to confounding, she noted. And the definition and cut-points for chronic migraine and overuse are arbitrary, she argued: "Even if medication overuse exists, there must be a spectrum of susceptibility."

It's also not clear whether withdrawal is effective. "If medication overuse is reversible, then detox should work. But does it? We don't have particularly good studies, but the level of evidence doesn't inspire confidence," she said. Some patients get better when they withdraw from their medication, but other factors -- including a doctor's time and attention -- also come into play, as well as natural history.

"We need control groups, not just observational studies," Loder emphasized. "Few detox studies have them. And often when they do, they often only tell you how many got better among the people who finished the study. That means that people who were not able to tolerate medication withdrawal may be different from people who were able to tolerate medication withdrawal, and often are not included in the success figures shown." A recent assessment of for example, indicated that "the outcome was not impressive; only about a third of people get better," she explained.

Besides the "unnecessary suffering that can result when people are arbitrarily told not to use pain medication, patients also suffer when we blame them as the architects of their own problems," Loder added. "It's probably time to take a more neutral view of medication overuse: patients and physicians should recognize that we cannot tell with certainty how much medication is too much."

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