Triclabendazole

7 DRUG INTERACTIONS CYP2C19 Substrates : Re-check the plasma concentration of concomitantly administered CYP2C19 substrates after cessation of EGATEN therapy, if the plasma concentrations of the CYP2C19 substrates are elevated during administration of EGATEN. ( 7.1 )

7.1 Effect of EGATEN on CYP2C19 Substrates No specific clinical drug interaction studies have been conducted for triclabendazole. However, in vitro data suggest the potential for increased plasma concentrations of CYP2C19 substrates with concomitant use of triclabendazole [see Clinical Pharmacology (12.3)] . The potential elevation in concentrations of concomitantly used CYP2C19 substrates is expected to be transient based on the short elimination half-life and short treatment duration of triclabendazole.

For those CYP2C19 substrate drugs that require therapeutic monitoring of systemic drug exposures, if the plasma concentrations of the CYP2C19 substrates are elevated during administration of triclabendazole, re-check the plasma concentration of the CYP2C19 substrates after cessation of triclabendazole therapy.

8.1 Pregnancy Risk Summary There are no available data on EGATEN use in pregnant women to inform a drug-associated risk of major birth defects, miscarriage or adverse maternal or fetal outcomes. Reproductive studies in animals (rat and rabbits) have not shown a risk of increased fetal abnormalities with exposure to triclabendazole during organogenesis at doses approximately 0.3 to 1.6 times the maximum recommended human dose (MRHD) of 20 mg/kg based on body surface area comparison (see Data) . The estimated background risk of major birth defects and miscarriage for the indicated population are unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes.

In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2%-4% and 15%-20%, respectively. Data Animal Data Embryo-fetal developmental toxicity studies revealed no malformations in rats and rabbits at doses up to 200 mg/kg/day and 20 mg/kg/day, respectively (approximately 1.6 times and 0.3 times the MRHD based on body surface area comparison, respectively). The animals were treated orally during organogenesis, starting on Day 6 of the pregnancy until Day 15 in rats and Day 18 in rabbits.

Maternal toxicity was noted at doses greater than or equal to 100 mg/kg/day in rats and 10 mg/kg/day in rabbits, which was associated with lower fetus weights and delayed ossification. These findings were considered indicative of delayed physiological growth that was secondary to maternal toxicity. No increase in malformation or other abnormalities was observed at any dose level in either species.