Safety in Lactation: Diuretics

Additional information relating to breastfeeding

To be used in conjunction with individual drug entries for specific information and guidance.

Thiazides and related diuretics
(includes bendroflumethiazide, chlortalidone, hydrochlorothiazide, indapamide, metolazone)

High dose thiazide diuretics have been used to suppress lacation, which may occasionally occur in lower doses. Levels in milk of most currently available thiazide diuretics have not been determined, but are likely to be too low to affect the infant. Monitor infant’s weight to determine adequate milk production.

Shorter-acting diuretics are preferred, and at the lowest dose and shortest time possible to achieve appropriate maternal benefit. Bendroflumethiazide preferred (most experience of use, short half life, high protein binding).

Loop diuretics
(includes bumetanide, furosemide, torasemide)

Loop diuretics may suppress lactation, although this is largely theoretical. Levels in milk of currently available loop diuretics have not been determined, but are likely to be too low to affect the infant. Monitor infant’s weight to determine adequate milk production.

Furosemide preferred (most experience of use, short half life, high protein binding, low oral bioavailability).

Potassium-sparing diuretics and aldosterone antagonists
(includes amiloride, eplerenone, spironolactone)

The indications for this group of drugs vary, for which spironolactone may not always be a suitable alternative. Amiloride is normally used in conjunction with thiazide or loop diuretics, the risks of which must also be taken into account. The diuretic action of these drugs is probably too weak to suppress lactation.