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Metronidazole is in pregnancy category B. Data on the use of metronidazole in pregnant women are conflicting. The available evidence suggests use during pregnancy has a low risk of congenital anomalies. Metronidazole may be used during pregnancy in those patients who will clearly benefit from the drug, although its use should be weighed against any potential risks.

Pregnancy Category B: Either animal-reproduction studies have not demonstrated a fetal risk but there are no controlled studies in pregnant women or animal-reproduction studies have shown an adverse effect (other than a decrease in fertility) that was not confirmed in controlled studies in women in the first trimester (and there is no evidence of a risk in later trimesters).

Metronidazole is excreted in breast milk. The American Academy of Pediatrics classifies metronidazole as a drug for which the effect on nursing infants is unknown but may be of concern. The World Health Organization (WHO) advises to avoid metronidazole treatment in lactating women. Metronidazole should be used during lactation only if the potential benefit of therapy to the mother justifies the potential risk to the infant.

The safety of metronidazole in children has not been established. Metronidazole is listed as an antiamebic and antigiardiasis medicine on the WHO Model List of Essential Medicines for Children, intended for the use of children up to 12 years of age.

Trimethoprim–sulfamethoxazole (TMP–SMX) is in pregnancy category C. TMP–SMX should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. TMP-SMX should be avoided near-term because of the potential for hyperbilirubinemia and kernicterus in the newborn.

Trimethoprim–sulfamethoxazole (TMP–SMX) is excreted in breast milk. TMP–SMX generally is compatible with breastfeeding of healthy, full-term infants after the newborn period. However, TMP-SMX generally should be avoided by women when nursing infants who are premature, jaundiced, ill, or stressed, or who have glucose-6-phosphate dehydrogenase deficiency.

The safety of trimethoprim–sulfamethoxazole (TMP–SMX) in children has not been systematically evaluated. Use in children less than 2 months of age generally is not recommended.

Nitazoxanide is in pregnancy category B. Data on the use of nitazoxanide in pregnant women are limited, and risk to the embryo-fetus is unknown. Nitazoxanide should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Pregnancy Category B: Either animal-reproduction studies have not demonstrated a fetal risk but there are no controlled studies in pregnant women or animal-reproduction studies have shown an adverse effect (other than a decrease in fertility) that was not confirmed in controlled studies in women in the first trimester (and there is no evidence of a risk in later trimesters).

It is not known whether nitazoxanide is excreted in breast milk. Nitazoxanide should be used with caution in breastfeeding women.

Nitazoxanide tablets should not be used in children age 11 years or younger as a single tablet contains a greater dose than recommended for pediatric dosing. Nitazoxanide oral suspension may be used for dosing in children, although the safety in children age 1 and younger is not certain.

Oral paromomycin has not been assigned to a pregnancy category by the Food and Drug Administration. Data on the use of oral paromomycin in pregnant women are limited, and the risk to the embryo-fetus probably is low. Oral paromomycin generally is poorly absorbed from the gastrointestinal tract, with minimal, if any, systemic availability.

Oral paromomycin is unlikely to be excreted in breast milk, and the drug generally is poorly absorbed from the gastrointestinal tract.

The safety of oral paromomycin in children has not been formally evaluated. However, the safety profiles likely are comparable in children and adults.

Oral iodoquinol has not been assigned a pregnancy category by the Food and Drug Administration. Data on the use of iodoquinol in pregnant women are limited, and risk to the embryo-fetus is unknown. Iodoquinol should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

It is not known whether iodoquinol is excreted in breast milk. Iodoquinol should be used with caution in breastfeeding women.

The safety of iodoquinol in children has not been established.

Ketoconazole is in pregnancy category C. Data on the use of ketoconazole in pregnant women are limited, and the risk to the embryo-fetus is unknown. Ketoconazole should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Pregnancy Category C: Either studies in animals have revealed adverse effects on the fetus (teratogenic or embryocidal, or other) and there are no controlled studies in women or studies in women and animals are not available. Drugs should be given only if the potential benefit justifies the potential risk to the fetus.

According to a case report, ketoconazole was excreted in breast milk and the nursing infant did not have adverse effects. The American Academy of Pediatrics classifies ketoconazole as compatible with breastfeeding.

The safety of ketoconazole has not been evaluated systematically for children of any age, and essentially no data are available about its use in children less than 2 years of age. Ketoconazole should not be used in children unless the potential benefit outweighs the risks.