Biohaven, the manufacturer of rimegepant (Nurtec ODT) just received FDA approval to market this drug for the prevention of migraines. Rimegepant was approved in January of 2020 for the acute treatment of migraine headaches. It is the first drug to be approved for both acute and preventive therapy of migraines.

Rimegepant is one of six drugs that block the action of calcitonin gene-related peptide (CGRP). CGRP has many important functions in the body but the release of excessive amounts of it in the brain can trigger a migraine. Four of the CGRP migraine drugs are given by injection and they are used only for the prevention of migraine attacks. Rimegepant and ubrogepant (Ubrelvy) are taken by mouth as needed, whenever a migraine strikes. These are truly novel drugs that have dramatically improved the lives of many migraine sufferers.

Rimegepant stays in the body longer – it has a half-life of 10-12 hours, while ubrogepant’s half-life is 7-8 hours. Another difference is that rimegepant dissolves in your mouth (ODT after Nurtec stands for orally disintegrating tablet), while ubrogepant is a solid tablet that is swallowed.

In clinical trials, rimegepant was noticed to provide relief of migraine that persisted for up to 48 hours. Because of this sustained effect, the researchers decided to test this drug for the prevention of migraine attacks by giving it every other day. And rimegepant passed this test. The official FDA-approved label says that for the prevention of migraines, one tablet of rimegepant should be taken every other day. For the acute treatment of migraines, the directions say to take 1 tablet a day, as needed.

The insurers typically pay for 8 tablets a month, although a few of my patients have been able to get 16. Now, with its approval for the prevention, patients will be able to get 16 tablets a month. It is possible that some patients may be able to get an additional 8 tablets for acute therapy. For most, however, 16 tablets a month should be sufficient.

The safety profile of rimegepant (as well as ubrogepant) is truly remarkable. The new rimegepant label states that “The most common side effects of NURTEC ODT were nausea (2.7%) and stomach pain/ indigestion (2.4%).” It also states that these are not the only possible side effects but their frequency is very low. Just like with any drugs, an allergic reaction is also possible.

My migraines respond very well to sumatriptan, but I do like to try new treatments that I recommend to my patients.

A few months ago two new abortive drugs to treat acute migraine attacks were approved by the FDA. Ubrelvy (ubrogepant) and Nurtec ODT (rimegepant) block CGRP, a substance released during a migraine attack. They work in a similar way to four injectable drugs used for the prevention of migraines – erenumab (Aimovig), fremanezumab (Ajovy), galcanezumab (Emgality), and eptinezumab (Vyepti). I’ve tried erenumab and fremanezumab with some relief, but stopped both because sumatriptan works well and I don’t really need any preventive medications.

Because the two injectable drugs did help, I expected the two new oral medications to work as well. Alas, neither one had any effect. This suggests that CGRP is not very operational in my case. The fact that sumatriptan, a drug that works on serotonin receptors works so well indicates that the serotonin system is dominant in producing my migraines.

Migraine is a very heterogeneous disorder with a variety of clinical presentations and with dozens of identified genetic abnormalities that predispose one to migraines. This means that we are not likely to have a drug that works for all migraine patients. What we do expect, is the advent of personalized medicine – having tests that predict which drug will work for which patient.

Rimegepant (NURTEC ODT) is the second gepant approved for the acute treatment of migraine headaches. It blocks the same CGRP pathway as the injectable monoclonal antibodies that are used for the prevention of migraine attacks (erenumab/Aimovig, fremanezumab/Ajovy, galcanezumab/Emgality, and eptinezumab/Vyepti).  It follows the recent introduction of a similar drug that also blocks the CGRP receptor, ubrogepant (Ubrelvy).

Since there have been no head-to-head trials comparing these two gepants, it is had to say if one is better than the other. On average, they appear to be very similar, but this does not mean that they will be equally effective or cause the same side effects in a particular patient. We see this with triptans (drugs like sumatriptan, eletriptan, and other) – the top 5 show similar efficacy in trials, but some patients strongly prefer one over another.

One difference is that rimegepant is an orally disintegrating tablet and does not require water, while ubrogepant is taken with water. This makes rimegepant easier to take on the go and could be easier to take for patients with severe nausea. Another minor difference is that the dose of rimegepant is 75 mg that is taken once a day, while ubrogepant comes in 50 and 100 mg tablets and either dose can be repeated for up to 2 tablets a day. This can be both an advantage and a disadvantage. The instructions are simple for rimegepant – take one tablet once on the day you have a migraine (and the earlier you take any abortive drug the better). With ubrogepant the doctor has to decide whether to give 50 or 100 mg dose and the patient needs to be instructed to take a second dose on the same day (as soon as 2 hours after the first one) if the headache returns or does not completely resolve with the first dose. In clinical trials, this second dose did produce additional improvement.

The safety of rimegepant is as remarkable as that of ubrogepant and the preventive injectable monoclonal antibodies. Rimegepant caused nausea in 2% of patients compared with 0.4% of those on placebo and less than 1% developed a rash or temporary difficulty breathing.