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Hydrochlorothiazide / triamterene Side Effects

Medically reviewed by Last updated on Jul 18, 2023.

Applies to hydrochlorothiazide / triamterene: oral capsule, oral tablet.


Oral route (Capsule)

Abnormal elevation of serum potassium levels (greater than or equal to 5.5 mEq/L (5.5 mmol/L)) can occur. Risk of hyperkalemia is increased in patients with renal impairment, diabetes (with or without renal impairment), the elderly, or severely ill. Serum potassium levels must be monitored at frequent intervals, especially in hydrochlorothiazide/triamterene-naive patients, when dosages are changed, or with any illness that may influence renal function

Serious side effects

Along with its needed effects, hydrochlorothiazide / triamterene may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking hydrochlorothiazide / triamterene:

Incidence not known

Get emergency help immediately if any of the following symptoms of overdose occur while taking hydrochlorothiazide / triamterene:

Symptoms of overdose

Other side effects

Some side effects of hydrochlorothiazide / triamterene may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Incidence not known

For Healthcare Professionals

Applies to hydrochlorothiazide / triamterene: oral capsule, oral tablet.


Frequency not reported: Diabetes mellitus, hyperkalemia, hyperglycemia, hyperuricemia, hypokalemia, hyponatremia, acidosis, hypochloremia, thirst, minor serum electrolyte changes, marked fluctuations in serum potassium levels[Ref]


Frequency not reported: Pancreatitis, nausea, vomiting, diarrhea, constipation, abdominal pain, dry mouth, sialadenitis[Ref]


Frequency not reported: Acute renal failure, interstitial nephritis, renal stones composed primarily of triamterene, BUN elevated, serum creatinine elevated[Ref]

There is no evidence that stone formation is increased in patients taking triamterene containing drugs.[Ref]


Frequency not reported: Rash, urticaria, photosensitivity, purpura[Ref]


Frequency not reported: Arrhythmias, postural hypotension, undesirable decrease in blood pressure[Ref]


Frequency not reported: Glycosuria, abnormal urinary sediment, impotence[Ref]


Frequency not reported: Leukopenia, thrombocytopenia, megaloblastic anemia


Frequency not reported: Thrombocytopenic purpura, megaloblastic anemia[Ref]


Frequency not reported: Jaundice, liver enzyme abnormalities[Ref]


Frequency not reported: Muscle cramps, systemic lupus erythematosus[Ref]

Nervous system

Frequency not reported: Dizziness, headache[Ref]


Frequency not reported: Weakness, fatigue[Ref]


Frequency not reported: Anaphylaxis[Ref]


1. (2002) "Product Information. Maxzide (hydrochlorothiazide-triamterene)." Lederle Laboratories

2. Cerner Multum, Inc. "UK Summary of Product Characteristics."

3. Cerner Multum, Inc. "Australian Product Information."

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.