VANCOUVER, BC—For patients with medication overuse headaches, discontinuation of overused medication and addition of preventive medication offers the best current treatment, results of a meta-analysis presented at the 68th AAN Annual Meeting have found. 

However, further studies are needed to devise the optimal course of care for medication overuse headaches, which affect approximately 1% to 2% of the U.S. population. 

“The optimal treatment strategy for medication overuse headache is unclear and the subject is of considerable debate,” noted Chia-Chun Chiang, MD, of the Department of Neurology at Mayo Clinic Arizona, Scottsdale, AZ, and colleagues in explaining the rationale for their systematic review.

To provide a comprehensive overview and an evidence-based discussion of different treatment strategies for medication overuse headache, the investigators identified 68 articles on PubMed published from 2004 to August 15, 2014, which they then reviewed for evidence according to AAN guidelines.

They found that 3 studies provided class III evidence on early discontinuation alone that demonstrated treatment strategies were possibly effective; however, a high failure rate and worsening of symptoms were reported and control groups were lacking. For example, Zeeberg et al. assessed the effect of a 2-month medication-free period in 337 patients with medication overuse headache. Among the 64% who completed the trial, 45% improved, 48% had no change, and 7% had an increase in headache frequency.

An additional 19 studies provided class III evidence on early discontinuation with preventive medication that also found treatments to be possibly effective, with encouraging outcomes; however, these lacked control groups as well. The COMOESTAS project reported a medication overuse headache treatment protocol or early discontinuation with adding preventive medication, Dr. Chiang reported. Among the 376 patients in the study, “66% were no longer overusing medications and 50% reverted to episodic headache 6 months after early discontinuation,” she added. 

A total of 17 studies provided class II–III evidence on preventive medication without early discontinuation; these included 2 class II studies for onabotulinumtoxinA and 2 class II studies for topiramate that showed these treatments to be “likely effective.” For the latter studies, medication overuse data were obtained from secondary analysis. The PREEMPT study found that onabotulinumtoxinA significantly reduced headache days vs. placebo; also reduced were total headache hours and HIT score for chronic migraine within the medication overuse subgroup. A study in patients with chronic migraine and medication overuse found significant reductions in mean monthly migraine days for patients treated with topiramate 100mg/day vs. placebo.

“Appropriately sized, randomized controlled trials evaluating the safety and long-term efficacy of preventive medication plus early discontinuation vs. preventive medication alone vs. early discontinuation alone for the treatment of medication overuse headache are needed,” Dr. Chiang concluded.