Erenumab & Migraines

Erenumab (brand name Aimovig) made history in 2018 as the first medication developed specifically to prevent migraines based on our understanding of migraine biology. It's a monoclonal antibody that targets the CGRP receptor. CGRP (calcitonin gene-related peptide) is a protein that spikes during migraine attacks and plays a major role in pain and inflammation.

Unlike older preventives that were borrowed from other conditions (blood pressure meds, antidepressants, anti-seizure drugs), erenumab was designed from the ground up for migraines. It works by sitting on the CGRP receptor and preventing CGRP from binding, which blocks its ability to trigger the inflammatory cascade that leads to migraine pain.

Erenumab is given as a once-monthly self-injection using a pre-filled autoinjector pen, similar to devices used for insulin or allergy medications. The injection is given under the skin (subcutaneously) in the abdomen, thigh, or upper arm. Available doses are 70 mg and 140 mg.

Many people start at 70 mg and move to 140 mg if they need more benefit. The injection takes about 15 seconds, and most people find it straightforward after the first time. Because it only needs to be taken once a month, adherence tends to be better than with daily pills. Some people notice benefit within the first month, but it's recommended to try it for at least three months.

Erenumab has a favorable side effect profile compared to many older preventives. The most common side effects include injection site reactions (redness, pain, swelling), constipation, and muscle cramps. Some people report constipation that can be significant, so staying hydrated and maintaining fiber intake is helpful.

Rarely, erenumab has been associated with elevated blood pressure, so monitoring is recommended, especially in the first few months. Because it's an antibody that targets a specific protein rather than broadly affecting neurotransmitter systems, it avoids many of the side effects seen with topiramate (cognitive issues, weight loss) or amitriptyline (drowsiness, weight gain).

Clinical trials show impressive results. In the STRIVE trial, erenumab 140 mg reduced monthly migraine days by an average of 3.7 days compared to 1.8 with placebo. About 50% of patients experienced at least a 50% reduction in monthly migraine days. Studies in chronic migraine (15+ headache days per month) showed similar benefit.

Erenumab may be especially valuable for people who haven't responded to or couldn't tolerate two or more traditional preventive medications. Insurance companies often require documentation of prior treatment failures before approving CGRP antibodies. This is where detailed tracking records become particularly useful for building a case for coverage.

Erenumab is a significant investment, and both you and your insurance company want to know it's working. Tracking your migraine frequency, severity, and medication use in CalmGrid before and after starting erenumab provides objective evidence of improvement (or lack thereof).

Many insurance plans require proof that the medication is reducing migraine frequency to continue authorizing it. Having three months of pre-treatment data and ongoing post-treatment data makes these conversations much easier. Your tracking can also help your doctor decide between the 70 mg and 140 mg doses or determine if erenumab should be combined with other preventive strategies.