Pregnancy: Pregnancy Category C. There are no adequate and well-controlled studies in pregnant women. The benefits against risk, particularly during the first trimester of pregnancy should be carefully weighed by a physician.
500 mg-1000 mg/kg/day dosing: Four studies in mice revealed a variable incidence of cleft palate after oral doses of 1000 mg/kg/day during gestation days 6 to 15. Cleft palate was also seen at 500 mg/kg/day. The 1000 mg/kg/day exposure resulted in plasma levels 17 times the human serum levels. In monkeys, an oral dose of 70 mg/kg/day produced fetal growth retardation at plasma levels 2 times the human serum levels.
125 mg-160 mg/kg/day dosing: Four teratogenicity studies in rats (oral and IV doses up to 160 mg/kg/day administered during the period of major organogenesis) and two in rabbits (at oral doses up to 125 mg/kg/day or IV doses of 30 mg/kg/day administered during gestation days 6 to 18) failed to demonstrate any teratogenicity from clarithromycin. Two additional oral studies in a different rat strain at similar doses and similar conditions demonstrated a low incidence of cardiovascular anomalies at doses of 150 mg/kg/day administered during gestation days 6 to 15. Plasma levels after 150 mg/kg/day were 2 times the human serum levels.
Embryonic loss has been seen in monkeys and rabbits.
Lactation: Since clarithromycin is distributed in human milk, caution should be exercised when the drug is given to breastfeeding women.