Samsca Use In Pregnancy & Lactation

Use in pregnancy: Pregnancy Category C. There are no adequate and well-controlled studies of Samsca use in pregnant women. In animal studies, cleft palate, brachymelia, microphthalmia, skeletal malformations, decreased fetal weight, delayed fetal ossification and embryo-fetal death occurred. Samsca should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
In embryo-fetal development studies, pregnant rats and rabbits received oral tolvaptan during organogenesis. Rats received 2-162 times the maximum recommended human dose (MRHD) of tolvaptan (on a body surface area basis). Reduced fetal weights and delayed fetal ossification occurred at 162 times the MRHD. Signs of maternal toxicity (reduction in body weight gain and food consumption) occurred at 16 and 162 times the MRHD. When pregnant rabbits received oral tolvaptan at 32-324 times the MRHD (on a body surface area basis), there were reductions in maternal body weight gain and food consumption at all doses, and increased abortions at the mid and high doses (about 97 and 324 times the MRHD). At 324 times the MRHD, there were increased rates of embryo-fetal death, fetal microphthalmia, open eyelids, cleft palate, brachymelia and skeletal malformations (see Toxicology: Nonclinical Toxicology under Actions).
Use in lactation: It is not known whether Samsca is excreted into human milk. Tolvaptan is excreted into the milk of lactating rats. Because many drugs are excreted into human milk and because of the potential for serious adverse reactions in nursing infants from Samsca, a decision should be made to discontinue nursing or the drug, taking into consideration the importance of Samsca to the mother.