Triamterene in Pregnancy and Breastfeeding

Risk Factor: CM*
Class: Diuretics

Contents of this page:
Fetal Risk Summary
Breast Feeding Summary
Questions and Answers

Fetal Risk Summary

Triamterene is a potassium-conserving diuretic. It is a weak folic acid antagonist. Reproduction studies in rats at doses up to 6 times the maximum recommended human dose based on body surface area found no evidence of fetal harm (1).

The drug crosses the placenta in animals (1). The molecular weight (about 253) is low enough that transfer to the human fetus should be expected.

No defects were observed in five infants exposed to triamterene in the 1st trimester (2, p. 372). For use anytime during pregnancy, 271 exposures were recorded without an increase in malformations (2, p. 441).

In a surveillance study of Michigan Medicaid recipients involving 229,101 completed pregnancies conducted between 1985 and 1992, 318 newborns had been exposed to triamterene during the 1st trimester (F. Rosa, personal communication, FDA, 1993). A total of 15 (4.7%) major birth defects were observed (13 expected). Three cases of cardiovascular defects (three expected) and one case of polydactyly (one expected) were observed, but specific information was not available for the other defects. No anomalies were observed in four other categories of defects (oral clefts, spina bifida, limb-reduction defects, and hypospadias) for which data were available. These data do not support an association between the drug and congenital defects.

The effects of exposure (at any time during the 2nd or 3rd month after the last menstrual period) to folic acid antagonists on embryo/fetal development were evaluated in a large, multicenter, case-control surveillance study published in 2000 (3). The report was based on data collected between 1976 and 1998 by the Slone Epidemiology Unit Birth Defects Study from 80 maternity or tertiary care hospitals in Boston, Philadelphia, Toronto, and Iowa. Mothers were interviewed within 6 months of delivery about their use of drugs during pregnancy. Folic acid antagonists were categorized into two groups: group Idihydrofolate reductase inhibitors (aminopterin, methotrexate, sulfasalazine, pyrimethamine, triamterene, and trimethoprim); group IIagents that affect other enzymes in folate metabolism, impair the absorption of folate, or increase the metabolic breakdown of folate (carbamazepine, phenytoin, primidone, and phenobarbital) (3). The case subjects were 3,870 infants with cardiovascular defects, 1,962 with oral clefts, and 1,100 with urinary tract malformations. Infants with defects associated with a syndrome were excluded, as were infants with coexisting neural tube defects (NTDs; known to be reduced by maternal folic acid supplementation). Too few infants with limb-reduction defects were identified to be analyzed. Controls (N=8,387) were infants with malformations other than oral clefts and cardiovascular, urinary tract, and limb-reduction defects and NTDs, but included infants with chromosomal and genetic defects. The risk of malformations in control infants would not have been reduced by vitamin supplementation, and none of the controls used folic acid antagonists (3). For group I cases, the relative risks (RRs) of cardiovascular defects and oral clefts were 3.4 (95% confidence interval [CI] 1.86.4) and 2.6 (95% CI 1.16.1), respectively. For group II cases, the RRs of cardiovascular and urinary tract defects, and oral clefts were 2.2 (95% CI 1.43.5), 2.5 (95% CI 1.25.0), and 2.5 (95% CI 1.54.2), respectively. Maternal use of multivitamin supplements reduced the risks in group I cases, but not in group II cases (3).

Many investigators consider diuretics to be contraindicated in pregnancy, except for patients with heart disease, because they do not prevent or alter the course of toxemia, and they may decrease placental perfusion (4,5 and 6). In general, diuretics are not recommended for the treatment of pregnancy-induced hypertension because of the maternal hypovolemia characteristic of this disease.

[*Risk Factor D if used in pregnancy-induced hypertension.]

Breast Feeding Summary

No reports describing the use of triamterene during lactation have been located. The molecular weight (about 253) is low enough that excretion into breast milk should be expected. The diuretic is excreted in animal milk (1). The potential effects of this exposure on a nursing infant are unknown.


  1. Product information. Dyrenium. WellSpring Pharmaceuticals, 2001.
  2. Heinonen OP, Slone D, Shapiro S. Birth Defects and Drugs in Pregnancy. Littleton, MA: Publishing Sciences Group, 1977.
  3. Hernandez-Diaz S, Werler MM, Walker AM, Mitchell AA. Folic acid antagonists during pregnancy and the risk of birth defects. N Engl J Med 2000;343:160814.
  4. Pitkin RM, Kaminetzky HA, Newton M, Pritchard JA. Maternal nutrition: a selective review of clinical topics. Obstet Gynecol 1972;40:77385.
  5. Lindheimer MD, Katz AI. Sodium and diuretics in pregnancy. N Engl J Med 1973;288:8914.
  6. Christianson R, Page EW. Diuretic drugs and pregnancy. Obstet Gynecol 1976;48:64752.

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Questions and Answers

Triamterene?, I've been taking Triamterene & Linisopril for over 5 yrs., but for the past 2 weeks the Triamterene has been causing severely frequent urination (urinating every hour!). My diet hasn't changed. Nothing has changed except this urination problem. I couldn't rest at night. When I stopped taking it, my hands and feet would swell up. How can I stop this swelling and why is this medicine affecting me like this? I know my doctor could tell me, but I'm just curious about your answers. Thanks.


Does nabumetone interact with triamterene or trazodone?,

No the osteoarthritis medication and diuretic wont react with one another or the antidepressent. BUT the antidepressent should not be taken if you have compromised kidneys. It can have adverse renal rxns.
talk to your doctor if you are concerned.
also the nabumetone has cardiovascular and GI risks.

Numbness up arms with Triamterene?, Hello,
I just took my first dose of Triamterene today about 3-4 hours ago and I am experiencing severe numbness and tingling in both arms, face, lips, and hands. I am also a bit dizzy and fatigued as well. Is this normal?

Not normal at all. Do not take any more and notify your physician as soon as possible.

anyone ever take phentermine or triamterene together for weight loss? what kind of results did you get?,

I took phentermine for a few months about 3 years back. I did not lose really fast. I did lose some though. In a month I went from 150 to 144. I think it permanently changed my brain. It made me real jittery at the time. My desk always used to be neat at my office. Now it is a big 'ol mess and has been ever since I took phentermine.

I tried a different tactic to lose weight and lost 30 lbs in two months, so now I am convinced that I no longer need pills to lose weight. I also believe now after trying the pills that if you have to use a pill to lose it, you'll need the pill to maintain it too.

In case you are curious, I lost the weight by avoiding foods that are highly processed and I avoided sugar as much as possible. You can research some of my answers to see some of the other things I did and didn't eat.

triamterene and Lisinopril?, I am currently on Triamterene. My doctor wants to put me on 10mg of Lisinopril. I am concerned because the pharmacy said the two combined can cause problems. I don't know if i should just go ahead and take it and trust my doctor. I feel if i call the office they will just be annoyed by me calling. He recently had put me on Adalat, which i had to discontinue because of problems.

The triamterene is a diuretic- lowers the volume of blood by increasing urination and lowers blood pressure that way. Lisinopril is an ACE inhibitor- lowering blood pressure by relaxing the blood vessles from constricting which will lower your blood pressure in THAT way.
Do not feel you are bothering your doctor by asking questions about your meds. An informed patient is a healthier patient because he/she is not asking important questions like this to strangers instead of their personal MD!!! You deserve to know about your care!

anyone know bout high blood pressure med.called triamterene?, This med. has left dark blood vessels on my moms legs and the dr. thinks thats normal and asures us that this med. is the best there is. I want to find out if anyone else has had same problem and if so is there something else you tried or heard about.

Side Effects of This Medicine

Check with your doctor as soon as possible if any of the following side effects occur:


For amiloride, spironolactone, and triamterene

Skin rash or itching; shortness of breath

For spironolactone and triamterene only (in addition to effects listed above)

Cough or hoarseness; fever or chills; lower back or side pain; painful or difficult urination

For triamterene only (in addition to effects listed above)

Black, tarry stools; blood in urine or stools; bright red tongue; burning, inflamed feeling in tongue; cracked corners of mouth; lower back pain (severe); pinpoint red spots on skin; unusual bleeding or bruising; weakness

Signs and symptoms of too much potassium

Confusion; irregular heartbeat; nervousness; numbness or tingling in hands, feet, or lips; shortness of breath or difficult breathing; unusual tiredness or weakness; weakness or heaviness of legs

Other side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. However, check with your doctor if any of the following side effects continue or are bothersome:

More common (less common with amiloride and triamterene)

Nausea and vomiting; stomach cramps and diarrhea

Less common

For amiloride, spironolactone, and triamterene

Dizziness; headache

For triamterene only (in addition to effects listed above for triamterene)

Increased sensitivity of skin to sunlight

Signs and symptoms of too little sodium

Drowsiness; dryness of mouth; increased thirst; lack of energy

Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.

The side effects listed above are those I found at one site and at another the following was found:


Adverse effects are listed in decreasing order of frequency; however, the most serious adverse effects are listed first regardless of frequency. All adverse effects occur rarely (that is, one in 1000, or less).

Hypersensitivity: anaphylaxis, rash, photosensitivity.

Metabolic: hyperkalemia, hypokalemia.

Renal: azotemia, elevated BUN and creatinine, renal stones, acute interstitial nephritis (rare), acute renal failure (one case of irreversible renal failure has been reported).

Gastrointestinal: jaundice and/or liver enzyme abnormalities, nausea and vomiting, diarrhea.

Hematologic: thrombocytopenia, megaloblastic anemia.

Central Nervous System: weakness, fatigue, dizziness, headache, dry mouth

Based on those 2 sites, I can't really say whether the side effect your mother is experiencing is a normal one or not (can't see it). However, I think I would ask if she could not be changed over to another medication. There are all kinds of different medications for high blood pressure out there and this side effect does not seem to be desirable.

Why would my Dr. prescribe Amlodipine Benazepril with Triamterene?, Lisinopril 10/12.5 worked great for me for 13yrs. BP started elevating and he started me on Norvasc 5mg. Worked for a week, BP elevated again. Now, he prescribed Amlodipine Benazepril with Triamterene. I have side effects from them all. My BP was still up the first time I took the Amlodipine and it is stated that this medicine can take as long as 2wks to see any effects. I can't tee tee when I take the Triamterene 75/50mg. I can't possibly be retaining that much fluid, I'm skinny as a race horse. I need some relief, not side effects. I don't trust my Dr.'s knowledge in prescribing medicine for me. My old Dr. did it right the first time. It seems as though this Dr. is just guessing. It is stated that Triamterene should not be used with Amlodipine. What do you say about this whole thing? I

That would be a really good question to ask your doctor... that's why you're paying him.
There very well may be something in your medical history that you don't realize is important (and in turn aren't mentioning to us), so anyone here would be making half-blind guesses... your doctor would have all the facts right at hand. It's really not a big deal to them because they are paid to help clients... that's their job.

If your doctor isn't available, you can ask a nurse or other hospital staff person and they can find out for you based on the reason he prescribed them and not a guess. Good luck!

what's the brand name for Triamterene w/hctz?,

The combination of triamterene and hydrochlorothiazide is used to treat high blood pressure and edema (fluid retention; excess fluid held in body tissues) in patients who have lower amounts of potassium in their bodies or for whom low potassium levels in the body could be dangerous. The combination of triamterene and hydrochlorothiazide is in a class of medications called diuretics ('water pills'). It causes the kidneys to get rid of unneeded water and sodium from the body into the urine, but reduces the loss of potassium.
Brand names
* Dyazide®
* Maxzide®

side effects of triamterene?,

Stop taking triamterene and seek emergency medical attention or contact your doctor immediately if you experience any of the following serious side effects:

an allergic reaction (difficulty breathing; closing of the throat; swelling of the lips, tongue, or face; or hives);
an irregular heartbeat, shortness of breath, fatigue, confusion, weakness, numbness, or tingling (caused by high levels of potassium in the blood); or
decreased urination.
Other, less serious side effects may be more likely to occur. Continue to take triamterene and talk to your doctor if you experience

nausea, diarrhea, or decreased appetite;
headache or dizziness;
dry mouth;
muscle cramps; or
lowering of the voice, excessive hair growth, or enlarged breasts.
Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome.