[What is the optimal dose for the prophylactic treatment of chronic migraine patients?].

Introduction: OnabotulinumtoxinA (OnabotA) is indicated for headache prophylaxis in patients with chronic migraine. However, there is some controversy about what is the minimum effective dose for treating chronic migraine patients.

Aim: To determine the optimal dose of OnabotA for the prophylactic treatment of patients with chronic migraine.

Development: We performed a literature review of the randomized, double blind, placebo-controlled studies that have evaluated the safety and efficacy of OnabotA as headache prophylactic treatment in migraine patients. In the studies conducted before the PREEMPT clinical programme, a variety of dose ranges and infiltration paradigms were used. Initial phase II studies of OnabotA in chronic daily headache showed that those patients treated with 150 U had significant mean reductions from baseline in headache frequency compared with placebo, and this benefit was not observed for patients treated with 75 U. The experience from previous studies allowed to define an injection paradigm and dose range (155-195 U) that was used in the PREEMPT clinical trials. PREEMPT studies demonstrate that OnabotA is a safe an effective prophylactic treatment for chronic migraine.

Conclusions: Available evidence to date supports that the optimal dose for the treatment of chronic migraine patients is the use of at least 150 U of OnabotA, that should be administered according to the PREEMPT injection paradigm.