No

Diuretic, Potassium Sparing

Alone or in combination with other diuretics to treat edema and hypertension; decreases potassium excretion caused by kaliuretic diuretics

B (per manufacturer); D (per expert analysis)

Clinical effects on the fetus: No data available. Generally, use of diuretics during pregnancy is avoided due to risk of decreased placental perfusion.

Breast-feeding/lactation: No data available

Hypersensitivity to triamterene or any component; patients receiving other potassium-sparing diuretics; anuria; severe hepatic disease; hyperkalemia or history of hyperkalemia; severe or progressive renal disease; pregnancy

Avoid potassium supplements, potassium-containing salt substitutes, a diet rich in potassium, or other drugs that can cause hyperkalemia. Monitor for fluid and electrolyte imbalances. Diuretic therapy should be carefully used in severe hepatic dysfunction; electrolyte and fluid shifts can cause or exacerbate encephalopathy. Use cautiously in patients with history of kidney stones and diabetes. Can cause photosensitivity.

1% to 10%:

Cardiovascular: Hypotension, edema, congestive heart failure, bradycardia

Central nervous system: Dizziness, headache, fatigue

Gastrointestinal: Constipation, nausea

Respiratory: Dyspnea

<1% (Limited to important or life-threatening symptoms): Inability to achieve or maintain an erection, agranulocytosis, thrombocytopenia

Symptoms of overdose include drowsiness, confusion, clinical signs of dehydration, electrolyte imbalance, and hypotension; chronic or acute ingestion of large amounts of potassium-sparing diuretics, may result in life-threatening hyperkalemia especially with decreased renal function.

If the EKG shows no widening of the QRS or an arrhythmia, discontinue triamterene and any potassium supplement and substitute a thiazide. Consider Kayexalate® to increase potassium excretion. If an abnormal cardiac status is obvious, treat with calcium or sodium bicarbonates as needed, pacing dialysis and/or Kayexalate®. Infusions of glucose and insulin are also useful.

Angiotensin-converting enzyme inhibitors can cause hyperkalemia, especially in patients with renal impairment, potassium-rich diets, or on other drugs causing hyperkalemia; avoid concurrent use or monitor closely.

Potassium supplements may further increase potassium retention and cause hyperkalemia; avoid concurrent use.

Interferes with potassium/sodium exchange (active transport) in the distal tubule, cortical collecting tubule and collecting duct by inhibiting sodium, potassium-ATPase; decreases calcium excretion; increases magnesium loss

Onset of action: Diuresis occurs within 2-4 hours

Duration: 7-9 hours

Absorption: Oral: Unreliable

Adults: Oral: 100-300 mg/day in 1-2 divided doses; maximum dose: 300 mg/day

Dosing adjustment in hepatic impairment: Dose reduction is recommended in patients with cirrhosis.

This diuretic does not cause you to lose potassium; because salt substitutes and low-salt milk may contain potassium, do not use these products without checking with your physician, too much potassium can be as harmful as too little; may be administered with food

Blood pressure, serum electrolytes (especially potassium), renal function, weight, I & O

Interferes with fluorometric assay of quinidine

Triamterene is usually combined with other antihypertensive agents for the treatment of hypertension. Triamterene may cause hyperkalemia, the EKG manifestations of which include peaked T waves, QRS prolongation, and cardiac conduction abnormalities.

May cause drowsiness or dizziness

Triamterene may increase the side effects of amantadine (dizziness, nausea, dry mouth) necessitating a decrease in dosage; monitor

No information available to require special precautions

No effects or complications reported

Take as directed, preferably after meals. This diuretic does not cause potassium loss; avoid excessive potassium intake (eg, salt substitutes, low-salt foods, bananas, nuts). Weigh yourself daily at the same time, in the same clothes, and report weight loss greater than 5 lb/week. Urine may appear blue (normal). You may experience dizziness, drowsiness, headache (use caution when driving or engaging in tasks requiring alertness until response to drug is known); nausea (small frequent meals, frequent mouth care, sucking lozenges, or chewing gum may help); decreased sexual ability (reversible with discontinuing of medication); or postural hypotension (change position slowly when rising from sitting or lying). Report persistent fatigue, muscle weakness, paresthesia, confusion, anorexia, headaches, lethargy, hyper-reflexia, seizures, swelling of extremities or respiratory difficulty (eg, chest pain, rapid heartbeat or palpitations). Pregnancy/breast-feeding precautions: Do not get pregnant while taking this medication; use appropriate barrier contraceptive measures. Consult prescriber if breast-feeding.

Observe for hyperkalemia; assess weight and I & O daily to determine weight loss; if ordered once daily, dose should be given in the morning

Capsule: 50 mg, 100 mg

Hollenberg NK and Mickiewicz CW, "Postmarketing Surveillance in 70,898 Patients Treated With a Triamterene/Hydrochlorothiazide Combination (Maxzide®)," Am J Cardiol, 1989, 63(4):37B-41B.