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Triamterene Side Effects

For the Consumer

Applies to triamterene: oral capsule, oral tablet

As well as its needed effects, triamterene may cause unwanted side effects that require medical attention.

Major Side Effects

If any of the following side effects occur while taking triamterene, check with your doctor immediately:

Incidence not known:
  • Abdominal or stomach pain
  • agitation
  • black, tarry stools
  • bleeding gums
  • blood in the urine or stools
  • chills
  • clay-colored stools
  • cloudy urine
  • confusion
  • convulsions
  • cough
  • dark urine
  • decreased urine output
  • depression
  • difficulty breathing
  • difficulty swallowing
  • dizziness
  • dry mouth
  • fainting spells
  • fast or irregular heartbeats
  • fever
  • headache
  • hives
  • hostility
  • increased thirst
  • irritability
  • itching
  • joint pain
  • lethargy
  • loss of appetite
  • loss of consciousness
  • mood changes
  • muscle pain or cramps
  • muscle twitching
  • nausea or vomiting
  • nervousness
  • numbness or tingling in the hands, feet, or lips
  • pain in the groin or genitals
  • pain in the lower back or side
  • pinpoint red spots on the skin
  • puffiness or swelling of the eyelids or around the eyes, face, lips or tongue
  • rapid or unusual weight gain
  • seizures
  • sharp back pain just below the ribs
  • shortness of breath
  • skin rash
  • stupor
  • swelling of the face, ankles, feet, or hands
  • tightness in the chest
  • unpleasant breath odor
  • unusual bleeding or bruising
  • unusual tiredness or weakness
  • vomiting of blood
  • weakness or heaviness of the legs
  • wheezing
  • yellow eyes or skin

If any of the following symptoms of overdose occur while taking triamterene, get emergency help immediately:

Symptoms of overdose:
  • Blurred vision
  • diarrhea
  • dizziness, faintness, or lightheadedness when getting up from a lying or sitting position suddenly
  • indigestion
  • pain or weakness in the hands or feet
  • passing of gas
  • stomach fullness or discomfort
  • sweating
  • trembling

Minor Side Effects

Some triamterene side effects may not need any medical attention. As your body gets used to the medicine these side effects may disappear. Your health care professional may be able to help you prevent or reduce these side effects, but do check with them if any of the following side effects continue, or if you are concerned about them:

Incidence not known:
  • Increased sensitivity of skin to sunlight
  • redness or other discoloration of the skin
  • severe sunburn

For Healthcare Professionals

Applies to triamterene: compounding powder, oral capsule


Gastrointestinal side effects, such as nausea and vomiting, may be lessened by administering the drug after meals.[Ref]


Hematologic side effects include thrombocytopenia and macrocytic anemia. Rare cases of drug-induced dose-dependent hemagglutination resulting in acute intravascular hemolysis is reported.[Ref]

Triamterene inhibits dihydrofolate reductase, resulting in decreased folate production. This may be important in patients who have borderline folate stores, such as pregnant women and alcohol abusers.[Ref]


Hepatic side effects are rare. A case of cholestatic jaundice and centrolobular necrosis of the liver is reported, thought to be due to hypersensitivity. Triamterene may cause a spurious elevation in serum lactate dehydrogenase concentrations.[Ref]


Hypersensitivity reactions include rare cases of drug fever, hepatitis, photosensitive dermatitis, and erythema multiforme. In some cases, other drugs were coadministered, making implication of triamterene difficult.[Ref]


Metabolic abnormalities include hyperkalemia, which is more likely in the elderly, diabetic, and in patients with renal insufficiency. It is recommended that serum potassium concentrations be monitored, and that an electrocardiogram be obtained if hyperkalemia is suspected to check for peaked T waves and QRS segment changes.[Ref]

The presence of an arrhythmia or widened QRS complex associated with hyperkalemia requires prompt administration of 10% calcium gluconate 10 to 20 mL intravenously over a 20 to 30 minute interval. Noncardiotoxic hyperkalemia usually responds to 10 units of regular insulin plus glucose 25 grams (as a 20% solution infused over 30 minutes) and consideration of sodium bicarbonate 40 to 150 mEq infused over a 30 to 60 minute interval. Insulin-dependent diabetic patients with preexisting hyperglycemia may not require the concomitant glucose infusion.[Ref]


A laboratory abnormality is spurious elevation of lactate dehydrogenase concentrations.[Ref]


Renal insufficiency, manifested as increased serum creatinine and BUN, has been reported in less than 1% of patients, but is far more likely, even in patients without preexisting renal insufficiency, if nonsteroidal anti-inflammatory drugs are being coadministered. Triamterene renal calculi is estimated to occur in 1/1,500 to 1/2,000 patients. Rare cases of interstitial nephritis and triamterene bladder calculi are reported.[Ref]

Triamterene is less soluble in solutions with a pH below 6, becoming crystallized and precipitating calculi formation under certain circumstances. In addition, triamterene alone, and when combined with hydrochlorothiazide, is associated with interstitial nephritis and acute renal failure in rare cases.[Ref]


1. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0

2. "Product Information. Dyrenium (triamterene)." SmithKline Beecham, Philadelphia, PA.

It is possible that some side effects of triamterene may not have been reported. These can be reported to the FDA here. Always consult a healthcare professional for medical advice.

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