Low Adherence and Persistence for Migraine Prophylactics

San Francisco—A literature review of studies examining adherence habits for migraine patients taking prophylactic medications found that there was low adherence and persistence for those taking propranolol, amitriptyline, and topiramate. The findings from the review were reported in a poster session at the AMCP meeting.

According to the poster, titled Migraine Prophylactic Adherence and Persistence: A Systematic Literature Review, it is estimated that migraines affect 12% of the American population and can have varying severity depending on the individual. Previous research has found that migraines are 3 times more likely to occur in women than men and have the highest prevalence among people 25 to 55 years of age.

Patients are often treated for migraines with first-line prophylaxis therapies including propranolol, amitriptyline, and topiramate; however, these medications are often associated with undesirable side effects and low adherence.

In this literature review, the poster’s authors evaluated previous research to determine migraine patients’ adherence and persistence to oral prophylactic medications. They identified previous studies using 2 databases to find prospective and retrospective observational studies on adherence and persistence of migraine prophylactics as well as randomized controlled trials (RCTs) involving propranolol, amitriptyline, and topiramate.

They excluded trials that studied the use of prophylactic medication for nonmigraine headaches, as well as case studies, expert opinions, animal studies, cost-effectiveness studies, pharmacokinetic studies, guidelines, studies not written in English, and studies involving children, the elderly or pregnant subpopulations.

The literature review assessed the 14 observational studies on an individual basis and pooled the results of the 19 RCTs identified.

Of the observational studies that were used, 6 studied oral migraine prophylactic adherence, and the remaining 8 investigated persistence.

The literature review found that, within the observational studies, there were low adherence rates among migraine patients taking prophylactics. Within 6 months, adherence rates in one study had dropped to just above 20%, while another study found adherence rates just below 60%. Adherence was also low for those studies that assessed patient behavior for a 12-month period, with one study reporting adherence rates near 35%.

Persistence rates were also found to decrease over time in the observational studies included in the review. One study reported a persistence rate of <10% at the 12-month mark; another study found a persistence rate of about 55% at 1-year.

When the authors of the review assessed data from the RCTs, they found that those patients using propranolol had a significantly higher rate of persistence compared with patients who took a placebo, amitriptyline, or topiramate in studies with follow-up of 16-26 weeks. They noted, however, that one reason for this finding could have been because the studies that evaluated propranolol use were smaller and older than some of the other studies included in the review.

Patients taking placebos had persistence rates that were comparable to those taking amitriptyline or topiramate; however, the reason for discontinued use varied based on treatment group. They found that patients taking a placebo were more likely to discontinue use due to other reasons, while those taking amitriptyline and topiramate had higher discontinuation rates due to adverse events than those patients taking placebos.

According to the authors, there were some possible limitations to the study such as reviewing only the top 3 medications used for migraine prophylaxis, discontinuation rates in RCTs that may not be generalizable, some discontinuation that may be due to changes in migraine frequency or severity, or the review’s use of weighted pooling of discontinuation rates in RCTs.

This study was supported by Allergan, Inc.