Diuretic
PREGNANCY RECOMMENDATION: No Human Data—Probably Compatible
BREASTFEEDING RECOMMENDATION: No Human Data—Probably Compatible
PREGNANCY SUMMARY
No reports describing the use of torsemide in human pregnancy have been located. Fetotoxicity was observed in animal studies but only with maternal toxic doses. In general, exposure to diuretics in early pregnancy has not been associated with structural anomalies, but the lack of human pregnancy experience with torsemide prevents a better assessment of the embryo–fetal risk. Diuretics do not prevent or alter the course of toxemia but may decrease placental perfusion (see also Chlorothiazide) because of maternal hypovolemia characteristic of this disease.
FETAL RISK SUMMARY
Torsemide is a loop diuretic in the same pharmacologic class as bumetanide, ethacrynic acid, and furosemide. The drug can be given orally or IV. Torsemide is indicated for the treatment of edema associated with congestive heart failure, renal disease, or hepatic disease. It is also indicated for the treatment of hypertension alone or in combination with other antihypertensive agents. Torsemide undergoes hepatic metabolism to primarily inactive metabolites. Plasma protein binding is >99% and the elimination half-life is about 3.5 hours (1).
Reproduction studies have been conducted in rats and rabbits. In these species, doses up to 10 and 1.7 times, respectively, the human dose of 20 mg/day based on BSA caused no fetotoxicity or teratogenicity. Doses that were 5 (rats) and 4 (rabbits) times larger caused maternal toxicity (decreased average body weight) and fetal toxicity (increased resorptions and delayed ossification) (1).
No overall increase in tumor incidence was noted when torsemide was given to rats and mice throughout their lives. In addition, no mutagenic activity was noted in a variety of assays and no adverse effects were noted on the reproductive performance of male and female rats (1).
It is not known if torsemide crosses the human placenta. The molecular weight (about 348) and moderate elimination half-life suggest that the drug will cross, but the high plasma protein binding may limit the amount available for transfer.
BREASTFEEDING SUMMARY
No reports describing the use of torsemide during human lactation have been located. The molecular weight (about 348) and moderate elimination half-life (about 3.5 hours) suggest that the drug will be excreted into breast milk, but the high plasma protein binding (>99%) should limit the amount in milk. The effect of this exposure on a nursing infant is unknown, but no adverse effects in nursing infants exposed to diuretics in milk have been reported. Of note, however, thiazide diuretics have been used to suppress lactation (see Chlorothiazide).
Reference
1.Product information. Demadex. Roche Pharmaceuticals, 2003.