Pregnancy: The safety of clarithromycin for use in pregnancy has not been established. Based on variable results obtained from animal studies and experience in humans, the possibility of adverse effects on embryofetal development cannot be excluded. Some observational studies evaluating exposure to clarithromycin during the first and second trimester have reported an increased risk of miscarriage compared to no antibiotic use or other antibiotic use during the same period. The available epidemiological studies on the risk of major congenital malformations will use of macrolides including clarithromycin during pregnancy provide conflicting results. Therefore, use during pregnancy is not advised without carefully weighing the benefits against risks.
Breastfeeding: Clarithromycin is excreted into human breast milk in small amounts. It has been estimated that an exclusively breastfed infant would receive about 1.7% of maternal weight-adjusted dose of clarithromycin.
The safety of clarithromycin use during breast-feeding of infants has not been established.
Fertility: In the rat, fertility studies have not shown any evidence of harmful effects (see PHARMACOLOGY: TOXICOLOGY: PRE-CLINICAL SAFETY DATA UNDER ACTIONS).