of 30, 100, and 200mg/kg/day) were administered orally during the period of major organogenesis (gestation days 7 to 29) to encompass the late period of external genitalia development. Histological eva luation of the genital papilla of fetuses revealed evidence of feminization of the male fetus at all doses. A second embryo-fetal study in rabbits at 0.3- to 53-fold the expected clinical exposure (animal doses of 0.05, 0.4, 3.0, and 30mg/kg/day) also produced evidence of feminization of the genitalia in male fetuses at all doses.
In an oral pre- and post-natal development study in rats, dutasteride doses of 0.05, 2.5, 12.5, or 30mg/kg/day were administered. Unequivocal evidence of feminization of the genitalia (i.e., decreased anogenital distance, increased incidence of hypospadias, nipple development) of male offspring occurred at 14- to 90-fold the MRHD (animal doses of 2.5mg/kg/day or greater). At 0.05-fold the expected clinical exposure (animal dose of 0.05 mg/kg/day), evidence of feminization was limited to a small, but statistically significant, decrease in anogenital distance. Animal doses of 2.5 to 30mg/kg/day resulted in prolonged gestation in the parental females and a decrease in time to vaginal patency for female offspring and a decrease in prostate and seminal vesicle weights in male offspring. Effects on newborn startle response were noted at doses greater than or equal to 12.5mg/kg/day. Increased stillbirths were noted at 30mg/kg/day.
In an embryo-fetal development study, pregnant rhesus monkeys were exposed intravenously to a dutasteride blood level comparable to the dutasteride concentration found in human semen. Dutasteride was administered on gestation days 20 to 100 at doses of 400, 780, 1,325, or 2,010ng/day (12monkeys/group). The development of male external genitalia of monkey offspring was not adversely affected. Reduction of fetal adrenal weights, reduction in fetal prostate weights, and increases in fetal ovarian and testis weights were observed at the highest dose tested in monkeys. Based on the highest measured semen concentration of dutasteride in treated men (14ng/mL), these doses represent 0.8 to 16times the potential maximum exposure of a 50-kg human female to 5mL semen daily from a dutasteride-treated man, assuming 100% absorption. (These calculations are based on blood levels of parent drug which are achieved at 32 to 186times the daily doses administered to pregnant monkeys on a ng/kg basis). Dutasteride is highly bound to proteins in human semen (greater than 96%), potentially reducing the amount of dutasteride available for vaginal absorption. It is not known whether rabbits or rhesus monkeys produce any of the major human metabolites.
Estimates of exposure multiples comparing animal studies to the MRHD for dutasteride are based on clinical serum concentration at steady state.
Tamsulosin: Administration of tamsulosin to pregnant female rats at dose levels up to approximately 50times the human therapeutic AUC exposure (animal dose of 300mg/kg/day) revealed no evidence of harm to the fetus. Administration of tamsulosin hydrochloride to pregnant rabbits at dose levels up to 50mg/kg/day produced no evidence of fetal harm. However, because of the effect of dutasteride on the fetus, JALYN is contraindicated for use in pregnant women. Estimates of exposure multiples comparing animal studies to the MRHD for tamsulosin are based on AUC.
8.3 Nursing Mothers
JALYN is contraindicated for use in women of childbearing poten |
