A new report suggests that CGRP-blocking drugs (CGRP-A) are safe in pregnancy.
Triptans (drugs like sumatriptan or Imitrex and six others) were introduced over 30 years ago. We know from pregnancy registries, retrospective, and prospective observational studies that triptans are safe in pregnancy.
The WHO database had 467 safety reports of exposure to CGRP-A in pregnancy. Of these, 386 were reports of exposure to CGRP monoclonal antibodies (mAbs), 76 to gepants, and 5 to both. The authors found “…no signals of increased reporting with CGRP-A compared to triptans in relation to pregnancy”.
CGRP drugs represent a major breakthrough in treating migraine headaches. A large proportion of migraine sufferers are women of childbearing age. We always have to consider the effect of a drug on the developing fetus. Erenumab (Aimovig), the first drug in this category was introduced almost six years ago. This is a relatively short period to assess the safety of a drug in pregnant women and the current report is not a definitive proof of safety.
There might be a difference in safety between oral CGRP antagonists (gepants), which are small molecules and injectable mAbs, which are large molecules. Gepants have the advantage of being completely washed out of the body within a few days of stopping them. Monoclonal antibodies are injected every one or three months and can take a few months to completely leave the body. However, mAbs, being larger, cannot cross the placenta in the first trimester. So if a mAb is stopped at the beginning of pregnancy the exposure to the fetus will be small.
The gepants include ubrogepant (Ubrelvy), rimegepant (Nurtec), atogepant (Qulipta), and a nasal spray, zavegepant (Zavzpret). The monoclonal antibodies are erenumab, fremanezumab (Ajovy), galcanezumab (Emgality), and eptinezumab (Vyepti).
