Hydrochlorothiazide / triamterene Pregnancy and Breastfeeding Warnings
Hydrochlorothiazide / triamterene Pregnancy Warnings
The Collaborative Perinatal Project monitored 50,282 mother-child pairs, of whom 233 were exposed to thiazide or related diuretics during the first trimester. An increased risk of malformations was found for thiazide diuretics. Use of thiazides after the first trimester does not seem to carry this risk. Thiazide diuretics may, however pose metabolic risks to the mother and fetus (hyponatremia, hypokalemia, thrombocytopenia, hyperglycemia), and may have a direct effect on smooth muscle, resulting in inhibition of labor. Cases of neonatal thrombocytopenia associated with antepartum administration of thiazide diuretics have been reported. Data from the Michigan Medicaid Birth Defects study failed to reveal an association between triamterene or thiazide diuretics and congenital defects (written communication, Franz Rosa, MD, Food and Drug Administration, 1994). Of 229,101 completed pregnancies between 1985 and 1992, 318 were exposed to triamterene at some time during the first trimester and 640 were exposed to the drug at any time during pregnancy. Of these pregnancies, 15 total and 3 cardiovascular defects were observed (13 and 3 were expected, respectively). A single case of cleft palate was observed. None of the observations achieved statistical significance. Regarding hydrochlorothiazide (HCTZ), this report is a summary of two studies, one in which 390 of 104,000 pregnant women from 1980 to 1983, and one in which 567 of 229,101 pregnant women from 1985 to 1992 received HCTZ. In the first study 28 total and 6 cardiovascular birth defects were observed (25 and 4 were expected, respectively). In the second study, 24 total defects and 7 cardiovascular defects were observed (22 and 6 were expected, respectively). Cleft palate was not associated with HCTZ. These data do not support an association between triamterene or HCTZ and congenital defects.
Hydrochlorothiazide-triamterene has been assigned to pregnancy category C by the FDA. No animal or human pregnancy data on the combination drug are available. In general, diuretics are often considered contraindicated in pregnancy, except for patients with heart disease, since they may decrease placental perfusion. Animal studies in rats have failed to reveal evidence of teratogenicity when given triamterene in doses up to 30 times the human dose (on a per kg basis). No controlled studies in human pregnancy are available. Data have revealed active human placental passage of triamterene from mother to fetus. A retrospective study of 271 human exposures to triamterene during pregnancy revealed no increase in malformations. Hydrochlorothiazide-triamterene should only be given during pregnancy when there are no alternatives and benefit outweighs risk.
Hydrochlorothiazide / triamterene Breastfeeding Warnings
Hydrochlorothiazide-triamterene is excreted into human milk. Side effects in the nursing infant are unlikely, but experience with the combination drug or with triamterene alone is limited. Hydrochlorothiazide is considered compatible with breast-feeding by the American Academy of Pediatrics; however, the manufacturer recommends that due to the potential for serious adverse reactions in nursing infants, a decision should be made to discontinue nursing or discontinue the drug, taking into account the importance of the drug to the mother.
In one case, in which a mother was taking hydrochlorothiazide 50 mg daily, 25% of her plasma HCTZ concentration appeared in her milk. This usually represents an insignificant amount of hydrochlorothiazide to the infant such that adverse effects in the nursing infant are unlikely. No data are available on the excretion of triamterene alone into human milk.
Disclaimer: Every effort has been made to ensure that the information provided by Cerner Multum, Wolters Kluwer Health and Drugs.com is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This drug information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate that the drug or combination is safe, effective, or appropriate for any given patient. Multum Information Services, Inc. does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. Copyright 2000-2008 Multum Information Services, Inc. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse, or pharmacist.