Botulinum toxin type A wear-off phenomenon in chronic migraine patients: how long does the maximum efficiency last?

Safety of Onabotulinumtoxin A in Chronic Migraine: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

Some 14% of global prevalence, based on high-income country populations, suffers from migraine. Chronic migraine is very disabling, being characterized by at least 15 headache days per month of which at least 8 days present the features of migraine. Onabotulinumtoxin A, targeting the machinery for exocytosis of neurotransmitters and neuropeptides, has been approved for use in chronic migraine since 2010. This systematic review and meta-analysis appraises the safety of onabotulinumtoxin A treatment for chronic migraine and the occurrence of treatment-related adverse events (TRAEs) in randomized, clinical studies in comparison with placebo or other comparators and preventative treatments according to the most updated Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) 2020 recommendations. The search retrieved 888 total records. Nine studies are included and seven were eligible for meta-analysis. The present study demonstrates that toxin produces more TRAEs than placebo, but less than oral topiramate, supporting the safety of onabotulinumtoxin A, and highlights the heterogeneity of the studies present in the literature (I² = 96%; p < 0.00001). This points to the need for further, adequately powered, randomized clinical trials assessing the safety of onabotulinumtoxin A in combination with the newest treatment options.

Impacts of the preempt protocol on chronic migraine: an integrative review

Chronic migraine is an important cause of functional disability and quality of life deficits, affecting 12% of the world population. Therefore, more treatment alternatives that promote better pain control are needed. So, botulinum toxin type A presents itself as a therapeutic option for this purpose. This integrative review aimed to analyze the functionality of the PREEMPT protocol applied for the treatment of chronic migraine, analyzing the time of pain control, the frequency of repetition of the treatment and the possible subtypes of pain that benefit most from botulinum toxin. Data were collected from the National Library of Medicine and Lilacs databases, and the research concluded in July 2022. 31 articles were found, of which only 22 publications were considered eligible to compose this study, and those that contemplated the research objectives were selected. above. Botulinum toxin type A presents an effective, safe and well-tolerated preventive profile for patients with chronic migraine, increasing the patient's quality of life and works in pain control.

Migraine Prevention with Erenumab: Focus on Patient Selection, Perspectives and Outcomes

Erenumab is a monoclonal antibody targeting the calcitonin gene-related peptide (CGRP) receptor suitable for episodic and chronic migraine prevention. Randomized clinical trials proved the superiority of erenumab to placebo in a strictly selected population, while real-world studies confirmed treatment efficacy in more severe forms of disease – most patients suffered from chronic migraine with medication overuse headache, had prior treatment failures, and long disease duration. According to guidelines, anti-CGRP pathway monoclonal antibodies should be reserved to patients who failed or have contraindication to several classes of preventive treatments. However, their ease of use, tolerability and efficacy make these monoclonal antibodies ideally suitable for most patients with migraine; cost-effectiveness needs to be considered when looking at expanding current prescription criteria. Also, data from open label extensions of randomized control trials confirmed sustained benefits of prolonged treatment up to 5 consecutive years without significant risk of adverse events. Further studies will provide insights on optimal treatment duration to achieve migraine remission and predictors of treatment response. In the present work, we aimed at reviewing design and results of the main studies on erenumab and discussing treatment use in the current migraine prevention scenario; we also summarized the main ongoing research projects and provided clinical perspectives for the future.