Chlorothiazide and Breastfeeding

Summary of use during lactation

Amounts of chlorothiazide in milk are low, but high doses might suppress lactation. Low-dose chlorothiazide appears to be acceptable during lactation. Intense diuresis with large doses may decrease breastmilk production.

Drug levels in milk and infant serum

Maternal Levels. After a single dose of 500 mg of chlorothiazide orally, there was no detectable drug (<1 mg/L) in the breastmilk from 11 nursing mothers at 1, 2 and 3 hours after the dose.[1] Infant Levels. Relevant published information was not found as of the revision date.

Effects in breastfed infants

Relevant published information was not found as of the revision date.

Effects on lactation and breastmilk

Relevant published information on chlorothiazide was not found as of the revision date. Intense diuresis with thiazides and thiazide-like diuretics, fluid restriction and breast binding have been used to suppress postpartum lactation.[2-4] The added contribution of the diuretic to these measures, which are effective in suppressing lactation, has not been studied. There are no data on the effects of diuretics on established, ongoing lactation.

Alternative drugs to consider

Hydrochlorothiazide

References

1. Werthmann MW, Jr, Krees SV. Excretion of chlorothiazide in human breast milk. J Pediatr 1972;81:781–3.5074355 PubMed
2. Healy M. Suppressing lactation with oral diuretics. Lancet 1961;277:1353–4. doi:10.1016/S0140-6736(61)90289-6
3. Stout G. Suppression of lactation. Br Med J 1962;1:1150.18117911 PubMed
4. Reiher KH. Suppression of lactation by stimulation of diuresis. Zentralbl Gynakol 1963;85:188–90.13973786 PubMed