Triamterene

DEA Class; Rx

Common Brand Names; Dyrenium

• Diuretics, Potassium-Sparing

Potassium-sparing distal tubule diuretic; frequently used for hypokalemia or with HCTZ for HTN; relatively weak diuretic and antihypertensive; actions similar to amiloride, but triamterene increases urinary magnesium excretion while amiloride does not.

Indicated for the treatment of peripheral edema states (e.g., heart failure, idiopathic edema, nephrotic syndrome, ascites due to hepatic cirrhosis, secondary hyperaldosteronism), hypertension, or hypokalemia.

Hypersensitivity to triamterene

Anuria, severe liver disease, renal failure

Hyperkalemia

Concomitant use with K+-sparing diuretic, or K supplementation

• CHF
• Edema
• Hypotension
• Dizziness
• Fatigue
• HA
• Photosensitivity
• Rash
• Diarrhea
• Nausea
• Vomiting
• Hyperuricemia
• Nephrotoxicity
• GI upset
• Thrombocytopenia
• Nephrolithiasis
• Folic acid antagonism

Use caution in acid-base imbalance, electrolyte abnormalities, hyperuricemia or gout, liver disease, renal impairment, renal stones

Patients should be observed regularly for possible occurrence of blood dyscrasias, liver damage or other idiosyncratic reactions

Periodic BUN and serum potassium determinations should be made to check kidney function, especially in patients with suspected or confirmed renal insufficiency; particularly important to make serum potassium determinations in elderly or diabetic patients receiving drug; these patients should be observed carefully for possible serum potassium increases

Electrolyte imbalance often encountered in diseases such as congestive heart failure, renal disease or cirrhosis may be aggravated or caused independently by any effective diuretic agent including triamterene; use of full doses of a diuretic when salt intake is restricted can result in a low-salt syndrome

Triamterene can cause mild nitrogen retention, which is reversible upon withdrawal of drug and is seldom observed with intermittent (every-other-day) therapy

Therapy may cause a decreasing alkali reserve, with possibility of metabolic acidosis

By the very nature of their illness, cirrhotics with splenomegaly sometimes have marked variations in their blood; since triamterene is a weak folic acid antagonist, it may contribute to appearance of megaloblastosis in cases where folic acid stores have been depleted; periodic blood studies in these patients recommended; observe also for exacerbations of underlying liver disease

Triamterene has elevated uric acid, especially in persons predisposed to gouty arthritis

Triamterene reported in renal stones in association with other calculus components; drug should be used with caution in patients with histories of renal stones

Interferes with fluorescent assay of quinidine

Not recommended for pregnancy-induced HTN; use during pregnancy may increase risk of cardiovascular defects and oral cleft in child

Pregnancy Category: C

Lactation: Discontinue drug or nursing