Prevention of Chronic Migraine with Injection Medications: OnabotulinumtoxinA vs Monoclonal Antibodies

Introduction: Adults diagnosed with chronic migraine (CM) frequently experience severe pain, nausea, vomiting, sensitivity to light or sound, and blurred vision. All of which are not conducive to routine daily functioning. The purpose of this review article is to explore the efficacy of preventative medications for CM such as OnabotulinumtoxinA injections (onabotA) and calcitonin gene-related peptide monoclonal antibodies (CGRP mAbs). Methods: PubMed was searched using “OnabotulinumtoxinA,” “chronic migraines,” and “monoclonal antibodies”, and related branch terms. The 263 results of this search were reduced to 20 with the following filters: published date 2020-2025, randomized controlled trials (RTCs), systematic review, meta-analysis, free full text and English language. Quality assessment of each article narrowed this search down to five. Results: Most articles assessed the efficacy of four CGRP mAbs, onabotA, and topiramate versus placebo, by measuring reduction in monthly migraine days. One article assessed individual preventative medications against combination therapy of CGRP mAbs and onabotA. In general, the articles agree that any preventative medication is better at preventing CM than placebo, and CGRP mAbs are modestly more effective than onabotA, at best. Discussion: CGRP mAbs and onabotA are safe and effective for CM prevention in adults. When choosing an injectable over an oral medication, it is important to consider dose frequency, patient preference, and potential adverse side effects for optimal individualized treatment. For continued best practice, additional research is needed to determine which CGRP mAb is superior, and if the efficacy of CGRP mAbs over onabotA is truly only modest at best.