Is there an increased risk of teratogenicity after treatment with rizatriptan and diclofenac during

Fråga: Is there an increased risk of teratogenicity after treatment with rizatriptan and diclofenac during pregnancy? A woman, now pregnant in week 11, has been treated with a few tablets of Maxalt (rizatriptan) during the first four weeks of pregnancy and 6 tablets per week of Voltaren (diclofenac) during the first seven weeks for migraine.

Sammanfattning: "Diclofenac is not associated with an increased risk for congenital malformation. Rizatriptan cannot be recommended during pregnancy as the documentation concerning the use of the drug in pregnant women is scarce. Animal data are not indicative of teratogenicity. If the use of a ""triptan"" is deemed necessary, sumatriptan can be considered. Although it is too early to consider sumatriptan completely safe to use during pregnancy, a significant number of expositions is not suggestive of increased teratogenic risk."

Svar: The question of diclofenac use during pregnancy has been answered previously. The drug is not associated with an increased risk for congenital malformation (1,2)

Rizatriptan (Maxalt) was given FDA approval in 1998 for the acute treatment of migraine headache (3). A search in Medline and pharmacological handbooks has not revealed any information about use of the drug in pregnant women. The manufacturer is aware of 29 reports of women exposed to rizatriptan sometime during pregnancy. Among them, 10 cases were lost to follow-up, 8 cases had spontaneous or induced abortion and 11 children were born without malformations (4). Animal studies showed no favour of teratogenic effects, although birth, fetal, and pre- and post-weaning weights were decreased (5). Pregnant rats treated with rizatriptan 10 mg/kg/d had pups with reduced weight, without signs of maternal toxicity. There was no increase in birth defects at up to 100 mg/kg/d. In rabbits, no increase in birth defects occurred at maternal doses of 50 mg/kg/d (6).

Sumatriptan is a similar drug which also belongs to the selective 5-HT1B/1D receptor agonists group (3,8). Questions on sumatriptan use during the first trimester of pregnancy have been answered in Drugline previously (9,10,11,12). No increase in the incidence of birth defect was seen. In the latest prospective study involving 168 pregnancies, 76 pregnant patients used sumatriptan after conception (75 during first trimester and one in both first and second trimesters), while 92 pregnant patients used sumatriptan only prior to conception. Exposure of the conceptus to sumatriptan during the first trimester appeared to have no adverse influence on perinatal pregnancy outcome (13). No data so far indicating teratogenic properties of sumatriptan have been located.

In a report from the Swedish Medical Birth Registry concerning 703 infants whose mothers were exposed to sumatriptan during early pregnancy, the frequency of malformations did not show any increase when compared to normal population (2.56 per cent versus 3.52 per cent) (14).