Loteprednol etabonate and tobramycin

8.1 Pregnancy Risk Summary There are no adequate and well-controlled studies with loteprednol etabonate or tobramycin in pregnant women. Loteprednol etabonate produced teratogenicity at clinically relevant doses in the rabbit and rat when administered orally during pregnancy. Loteprednol etabonate produced malformations when administered orally to pregnant rabbits at doses ≥ 0.54 times the recommended human ophthalmic dose (RHOD) and to pregnant rats at doses ≥ 13 times the RHOD.

In pregnant rats receiving oral doses of loteprednol etabonate during the period equivalent to the last trimester of pregnancy through lactation in humans, survival of offspring was reduced at doses ≥ 1.3 times the RHOD. Maternal toxicity was observed in rats at doses ≥ 135 times the RHOD, and a maternal no observed adverse effect level (NOAEL) was established at 13 times the RHOD. Abortions were observed in pregnant rabbits administered tobramycin via subcutaneous injection at 180 times the RHOD. Tobramycin did not affect fetal development when administered by subcutaneous injection to pregnant rats at doses 450 times the RHOD.

The background risk of major birth defects and miscarriage for the indicated population is unknown. However, the background risk in the U.S. general population of major birth defects is 2 to 4%, and of miscarriage is 15 to 20%, of clinically recognized pregnancies. Data Animal Data Embryofetal studies were conducted in pregnant rabbits administered loteprednol etabonate by oral gavage on gestation days 6 to 18, to target the period of organogenesis. Loteprednol etabonate produced fetal malformations at doses ≥ 0.1 mg/kg/day (0.54 times the recommended human ophthalmic dose (RHOD) based on body surface area, assuming 100% absorption of loteprednol etabonate).

Spina bifida (including meningocele) was observed at doses ≥ 0.1 mg/kg/day, and exencephaly and craniofacial malformations were observed at doses ≥ 0.4 mg/kg/day (2.1 times the RHOD). At 3 mg/kg/day (16 times the RHOD), loteprednol etabonate was associated with increased incidences of abnormal left common carotid artery, limb flexures, umbilical hernia, scoliosis, and delayed ossification. Abortion and embryofetal lethality (resorption) occurred at doses ≥ 6 mg/kg/day (32 times the RHOD). A NOAEL for developmental toxicity was not established in this study. The NOAEL for maternal toxicity in rabbits was 3 mg/kg/day.

Embryofetal studies were conducted in pregnant rats administered loteprednol etabonate by oral gavage on gestation days 6 to 15, to target the period of organogenesis. Loteprednol…