USE OF PIZOTIFEN IN PREGNANCY

Pizotifen is a sedating antihistamine with strong serotonin antagonist and weak antimuscarinic properties used in the prophylactic management of recurrent vascular headaches, migraines and cluster headaches. However, pizotifen is not effective in treating acute headache/migraine attacks.

The available data on pizotifen use in human pregnancy are extremely limited. Published data consist of a single case series of pizotifen-exposed pregnancies (n=12), from which there were no cases of major malformation. Unpublished national surveillance data collected by UKTIS include outcomes for 46 prospectively reported therapeutic pizotifen-exposed pregnancies, with first trimester exposure confirmed in 27 cases. Although these data do not signal that pizotifen is a major teratogen, the risk to the fetus following maternal use in pregnancy remains unknown.

Pizotifen use in pregnancy is therefore not routinely recommended unless compellingly indicated. Owing to the lack of published data regarding malformation risks, women who have been exposed to pizotifen in the first trimester are encouraged to attend their routine detailed fetal anomaly scan which is generally conducted at around 18 to 20 weeks of pregnancy.

Exposure to pizotifen at any stage in pregnancy would not usually be regarded as medical grounds for termination of pregnancy or any additional fetal monitoring. However, other risk factors may be present in individual cases which may independently increase the risk of adverse pregnancy outcome. Clinicians are reminded of the importance of consideration of such factors when performing case-specific risk assessments.