The Basics
What is Chlorothiazide?
A thiazide diuretic that reduces the amount of water in the body by increasing the flow of urine, to lower blood pressure and remove excess fluid (edema).
Brand names for Chlorothiazide
Diuril
How Chlorothiazide is classified
Antihypertensive Agents, Thiazide Diuretics
Chlorothiazide During Pregnancy
Chlorothiazide pregnancy category
Category CNote that the FDA has deprecated the use of pregnancy categories, so for some medications, this information isn’t available. We still think it’s useful to list historical info, however, given what a common proxy this has been in the past.
What we know about taking Chlorothiazide while pregnant
Although reproduction studies performed with chlorothiazide doses of 50 mg/kg/day in rabbits, 60 mg/kg/day in rats and 500 mg/kg/day in mice revealed no external abnormalities of the fetus or impairment of growth and survival of the fetus due to chlorothiazide, such studies did not include complete examinations for visceral and skeletal abnormalities. It is not known whether chlorothiazide can cause fetal harm when administered to a pregnant woman; however, thiazides cross the placental barrier and appear in cord blood. DIURIL (chlorothiazide) should be used during pregnancy only if clearly needed (see INDICATIONS AND USAGE).
Taking Chlorothiazide While Breastfeeding
What are recommendations for lactation if you're taking Chlorothiazide?
Low-dose chlorothiazide appears to be acceptable during lactation. Intense diuresis with large doses may decrease breastmilk production.
Maternal / infant drug levels
Low-dose chlorothiazide appears to be acceptable during lactation. Intense diuresis with large doses may decrease breastmilk production.
Possible effects of Chlorothiazide on milk supply
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][3][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.
Possible alternatives to Chlorothiazide
Hydrochlorothiazide.
List of References
Lactation sources: Drugs and Lactation Database (LactMed) [Internet]. Bethesda (MD): National Library of Medicine (US); 2006-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK501922/1. Werthmann MW Jr, Krees SV. Excretion of chlorothiazide in human breast milk. J Pediatr. 1972;81:781-3. PMID: 5074355
2. Healy M. Suppressing lactation with oral diuretics. Lancet. 1961;1:1353-4.
3. Stout G. Suppression of lactation. Br Med J. 1962;1:1150. Letter. PMC: PMC1958377
4. Reiher KH. [Suppression of lactation by stimulation of diuresis] Zentralbl Gynakol. 1963;85:188-90. PMID: 13973786
Disclaimer: This material is provided for educational purposes only and is not intended for medical advice, diagnosis, or treatment. Consult your healthcare provider with any questions.
