Rimegepant is a small molecule inhibitor of the calcitonin gene-related peptide (CGRP) receptor that blocks the action of CGRP, a potent vasodilator believed to play a role in migraine headaches. Rimegepant is approved for treatment of acute migraine attacks. In clinical trials, rimegepant was generally well tolerated with only rare instances of transient serum aminotransferase elevations during therapy and with no reported instances of clinically apparent liver injury.