Rimegepant

Two indications

Rimegepant is a calcitonin gene-related peptide (CGRP) receptor antagonist. The US product is an orally disintegrating tablet. Authorised use differs by region:

• US, Nurtec ODT. Acute treatment of migraine with or without aura, and preventive treatment of episodic migraine, in adults.
• EU, Vydura. Acute treatment of migraine with or without aura, and prevention of episodic migraine in adults with at least 4 attacks a month.
• UK, NICE TA919 (2023). Recommended for acute treatment only if, for previous migraines, at least 2 triptans did not work well enough, or triptans were contraindicated or not tolerated and NSAIDs and paracetamol did not work well enough. Prevention has a separate appraisal, TA906.

The dose and schedule differ between the two uses and come from the label or the prescriber.

Results at 2 hours

Study 1 in the US label compared one dose with placebo:

Outcome at 2 hours	Rimegepant	Placebo
Pain freedom	21.2% (142 of 669)	10.9% (74 of 682)
Freedom from most bothersome symptom	35.1% (235 of 669)	26.8% (183 of 682)

Each patient chose their most bothersome symptom from light sensitivity, sound sensitivity or nausea. About 14% of participants were taking a preventive at baseline. In the acute study, nausea occurred in 2% against 0.4% on placebo.

Contraindication and warnings

The label’s one contraindication is a history of hypersensitivity to rimegepant or any component of the product. Its warnings are:

• Hypersensitivity. Serious reactions, including anaphylaxis, dyspnea and rash, can occur, and may appear days after dosing.
• Hypertension. New or worsening high blood pressure has been reported.
• Raynaud’s phenomenon. New, recurrent or worsening cases have been reported.

The label says to avoid use in severe liver impairment and end-stage renal disease, and with strong CYP3A4 inhibitors and strong or moderate CYP3A inducers. It also restricts repeat doses with some other interacting medicines. Safety and effectiveness in pediatric patients have not been established. The label states that safety above a set number of doses in 30 days has not been established; the number is in the label.

Monthly limit

ICHD-3 was published in 2018, and its section 8.2 does not name gepants. Its general subtype 8.2.8 covers other acute medicines used on 10 or more days a month for more than 3 months. A 2021 American Headache Society consensus statement found that frequent use of rimegepant or ubrogepant does not appear to lead to medication-overuse headache. A 2024 commentary called the evidence inconclusive, because trials followed patients for at most 52 weeks (Pellesi 2024).

The medication days counter and Aurora do not count rimegepant against an ICHD-3 limit. This does not mean any frequency is safe. See gepants and lasmiditan.

In a headache diary

Mark each dose as acute or preventive, because the two uses have different schedules and only acute doses have a 2-hour outcome. For acute doses, record pain at 2 hours and your most bothersome symptom. Record days taken, so your doctor sees the whole picture.