From the Guidelines
Injections for migraine headaches should prioritize CGRP antagonists like erenumab, fremanezumab, or galcanezumab, or onabotulinumtoxinA injection for chronic migraine, as these have the strongest evidence for efficacy and safety 1. When considering injections for migraine headaches, several options are available, but the choice should be guided by the severity and frequency of migraines, as well as the patient's response to other treatments.
- For preventive treatment, CGRP antagonists such as erenumab, fremanezumab, or galcanezumab are recommended due to their strong evidence for reducing migraine frequency 1.
- OnabotulinumtoxinA injection is suggested for the prevention of chronic migraine, defined as 15 or more headache days per month 1.
- For acute migraine attacks, sumatriptan injections can provide rapid relief but should be used judiciously to avoid medication overuse headaches 1. Key considerations include the potential side effects of these treatments, such as injection site reactions, and the importance of trying oral preventatives before moving to injection therapies, unless the patient's condition warrants immediate initiation of injectable treatments 1.
- The dosing for these injections can vary, with CGRP antagonists typically administered monthly or quarterly, and onabotulinumtoxinA given every 12 weeks 1.
- It's crucial to weigh the benefits of these injections against their potential risks and to monitor patients closely for any adverse effects, ensuring the best possible outcome in terms of morbidity, mortality, and quality of life 1.
From the Research
Injections for Migraine Headaches
- Botulinum toxin type A has been licensed in some countries for chronic migraine treatment, with studies showing it may reduce the number of migraine days per month in the chronic migraine population by 3.1 days 2.
- The quality of the evidence for botulinum toxin versus placebo was low, with small trial size, high risk of bias, and unexplained heterogeneity being common reasons for downgrading the quality of the evidence 2.
- Botulinum toxin type A has been used in the treatment of chronic migraine for over a decade and has become established as a well-tolerated option for the preventive therapy of chronic migraine 3.
- The mode of action of botulinum toxin serotype A (BoNT/A) in migraine is not fully known, but may include modulation of neurotransmitter release, changes in surface expression of receptors and cytokines, as well as enhancement of opioidergic transmission 4.
- OnabotulinumtoxinA (Botox®) was approved by the FDA for the prophylactic treatment of chronic migraine in 2010, and has been shown to be effective in reducing headache frequency and severity in patients with chronic migraine 5.
- The efficacy of botulinum toxin in preventing migraine headache attacks remains controversial, and the underlying scientific rationale is debatable, with concerns including the antigenic and headache-provoking potential of botulinum toxin, and the possible placebo effect of needling 6.
Key Findings
- Botulinum toxin may reduce the number of migraine days per month in the chronic migraine population by 2 days compared to placebo treatment 2.
- Non-serious adverse events were probably experienced by 60/100 participants in the treated group compared to 47/100 in the placebo group 2.
- The relative risk reduction for withdrawing from botulinum toxin due to adverse events compared to the alternative prophylactic agent was 72% 2.
- Botulinum toxin has been shown to be effective in reducing headache frequency and severity in patients with chronic migraine, but its use in episodic migraine is still uncertain 2, 5.