GlaxoSmithKline, the manufacturer ofsumatriptan (Imitrex, Imigran)set up a registry in 1996 to gather data regarding prenatal exposure to sumatriptan. After seven years of gathering data, a report was recently presented at the 11th Congress of the International Headache Society (IHS).
To date, the registry contains information about 376 pregnancy outcomes, including 334 cases of first-trimester exposures. Of those 334 first-trimester exposures, birth defects were reported in:
- 10 live births
- 1 stillbirth
- 1 induced abortion
No defects were reported in:
- 286 live births
- 3 stillbirths
- 22 spontaneous abortions (miscarriages)
- 22 induced abortions
Sara Ephross of GlaxoSmithKline, who made the presentation, commented, "The proportion [of children] with birth defects is 4%, not significantly different from the expected general-population proportion. There was no consistent pattern among reported birth defects."
Shashidhar H. Kori, MD, director, Imitrex Clinical Development & Medical Affairs, pointed out that the results are encouraging, but it must be emphasized that sumatriptan still must not be used intentionally during pregnancy as more cases are needed to adequately assess the use of sumatriptan during pregnancy.
The report is good news, however for expectant mothers who may have taken sumatriptan before realizing they were pregnant. The patient information for sumatriptan currently states, "Pregnancy Category C ... There are no adequate and well-controlled studies in pregnant women. Therefore, IMITREX should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus."
At this time, all of the triptan class drugs carry the same warning.