The safety and efficacy of onabotulinumtoxinA for CM was demonstrated in the pivotal phase III Research Evaluating Migraine Prophylaxis Therapy (PREEMPT) trial. In this trial, patients were treated every 12 weeks whether or not their headaches had returned to baseline levels and the primary outcome period was after two treatment cycles. At baseline, these patients had more than 19 headache days, and after two treatment cycles, their headaches had been reduced by 8 to 9 days per 28 days. The responder rate analysis of the study population shows that about 25% of patients improved by 75% in terms of a reduction of migraine days. In my practice, I usually do three cycles 12 weeks apart, and only if there is no change in headache frequency after this, do I change treatments. In the pivotal trials, the first statistical separation from placebo occurred in the first 4 weeks. There is a small subgroup of patients who fail to respond to the first two treatments and only start to respond after the third treatment.4-10
Both Aetna and HealthPartners tell The Verge in an email that they don’t require patients to try verapamil specifically. “Verapamil is just one of many options available to treat migraines. Some are FDA-approved, others are not,” says Becca Johnson, a spokesperson for HealthPartners. Patients are required to try other oral medications because they’re either cheaper or not as invasive as getting Botox injections. “The rationale is that these medications are generally effective and safe,” says Ethan Slavin, a spokesperson for Aetna.
Tell your doctor if you have received any other botulinum toxin product in the last 4 months; have received injections of botulinum toxin such as Myobloc®, Dysport®, or Xeomin® in the past (tell your doctor exactly which product you received); have recently received an antibiotic by injection; take muscle relaxants; take an allergy or cold medicine; take a sleep medicine; take aspirin-like products or blood thinners.