Hydroch1orothiazide/Triamterene (HCTZ/Triamterene)

A to Z Drug Facts

Hydroch1orothiazide/Triamterene (HCTZ/Triamterene)

	Action
	Indications
	Contraindications
	Route/Dosage
	Interactions
	Lab Test Interferences
	Adverse Reactions
	Precautions
Patient Care Considerations
	Administration/Storage
	Assessment/Interventions
	Patient/Family Education

(high-droe-klor-oh-THIGH-uh-zide/try-AM-tur-een)

Maxzide-25MG, Dyazide, Maxzide, Apo-Triazide, Novo-Triamzide, Nu-Triazide, Pro-Triazide

Class: Diuretic combination

Action Hydroch1orothiazide inhibits reabsorption of sodium and chloride in ascending loop of Henle and early distal tubules. Triamterene interferes with sodium reabsorption at distal tubule. Combination provides additive diuretic activity and antihypertensive effects and minimizes potassium depletion.

Indications Treatment of edema or hypertension in patients who have or are at risk of developing hypokalemia.

Contraindications Anuria; renal decompensation; severe hepatic disease; hypersensitivity to thiazides, triamterene, or sulfonamide-derived drugs; patients receiving spironolactone, amiloride, or potassium supplements; hyperkalemia; metabolic or respiratory acidosis.

Route/Dosage

ADULTS: PO 1 to 2 tablets or capsules daily.

Interactions

Angiotensin-converting enzyme inhibitors: May result in severely elevated serum potassium levels. Allopurinol: May increase incidence of hypersensitivity reactions to allopurinol. Amantadine: May increase amantadine plasma levels and risk for adverse effects. Anticoagulants: May diminish anticoagulant effects. Bile acid sequestrants: May reduce thiazide absorption; give thiazide ³ 2 hr before sequestrant. Diazoxide: May cause hyperglycemia. Digitalis glycosides: Diuretic-induced hypokalemia and hypomagnesemia may precipitate digitalis-induced arrhythmias. Indomethacin: May cause rapid progression into acute renal failure. Lithium: May decrease renal excretion of lithium; monitor lithium levels. Loop diuretics: May cause synergistic effects that may result in profound diuresis and serious electrolyte abnormalities. Methenamines, NSAIDS: May decrease effectiveness of thiazide. Potassium preparations: May severely increase serum potassium levels, possibly resulting in cardiac arrhythmias or cardiac arrest. Monitor serum potassium closely if potassium is administered concurrently. Sulfonylureas, insulin: May decrease hypoglycemic effect of sulfonylureas. May need to adjust dosage of sulfonylureas or insulin.

Lab Test Interferences May interfere with the fluorescent measurement of quinidine serum levels. May decrease serum protein-bound iodine levels without signs of thyroid disturbance.

Adverse Reactions

CV: Orthostatic hypotension. CNS: Dizziness; lightheadedness; vertigo; headache; paresthesias; weakness; restlessness; insomnia; fatigue. DERM: Purpura; photosensitivity; rash; urticaria; necrotizing angitis, vasculitis, cutaneous vasculitis; alopecia; exfoliative dermatitis; toxic epidermal necrolysis; erythema multiforme; Stevens-Johnson syndrome. EENT: Blurred vision; xanthopsia (yellow vision). GI: Anorexia; gastric irritation; nausea; vomiting; abdominal pain or cramping; bloating; diarrhea; constipation; pancreatitis; sialadenitis; dry mouth. GU: Impotence; reduced libido; interstitial nephritis; azotemia; elevated BUN and creatinine. HEMA: Leukopenia; thrombocytopenia; agranulocytosis; aplastic or hypoplastic anemia; hemolytic anemia; megaloblastic anemia. HEPA: Jaundice; liver enzyme abnormalities. META: Hyperglycemia; glycosuria; hyperuricemia; hyperkalemia; electrolyte imbalance; hypochloremia; hyponatremia. OTHER: Muscle cramp or spasm; fever; anaphylactic reactions.

Precautions

Pregnancy: Category C. Lactation: Excreted in breast milk. Children: Safety and efficacy have not been established. Electrolyte imbalances and BUN increase: Hyperkalemia (serum potassium > 5.5 mEq/L), hyponatremia, hypochloremia, and increases in BUN may occur. Hematologic effects: Triamterene is a weak folic acid antagonist and may contribute to megaloblastosis. Hepatic impairment: Minor alterations of fluid and electrolyte balance may precipitate hepatic coma; use drug with caution. Hypersensitivity: May occur in patients with or without history of allergy or bronchial asthma; cross-sensitivity with sulfonamides may also occur. Lipids: May affect total serum cholesterol, total triglycerides, and LDL in some patients. Postsympathectomy patients: > Antihypertensive effects may be enhanced. Renal impairment: May precipitate azotemia or hypermagnesemia; use drug with caution. Renal stones: Triamterene has been found in renal stones; use drug with caution in patients with histories of stone formation.

PATIENT CARE CONSIDERATIONS

Administration/Storage

Administer as morning dose.
Give with food or milk.
Administer every other day to decrease electrolyte imbalance.
Store in tightly closed container at room temperature.

Assessment/Interventions

Obtain patient history, including drug history and any known allergies.
Weigh patient daily.
Measure I & O.
Monitor patient's BP with patient lying down and standing.
Monitor serum potassium, calcium, magnesium, sodium, ABGs, uric acid.
Monitor renal (nonprotein nitrogen, BUN, creatinine) and liver (ALT, AST) function tests.
Monitor blood glucose levels in diabetic patients.
Observe closely for anaphylaxis (shortness of breath, rash, edema) after first dose.
Report muscle weakness, cramps, nausea, blurred vision, or dizziness to health care provider.

OVERDOSAGE: SIGNS & SYMPTOMS
	Orthostatic or general hypotension, tachycardia, syncope, electrolyte abnormalities, potassium deficiency, vomiting, nausea, shock, weakness, confusion, dizziness, cramps of calf muscles, thirst, polyuria, anuria, lethargy

Patient/Family Education

Instruct patient to take medication early in day to avoid diuretic effect at night.
Tell patient to take drug with food or milk and to report GI symptoms.
Advise patient to limit sodium intake for optimal drug effect.
Advise patient to limit exposure to sun and to use sunscreen or wear protective clothing to avoid photosensitivity reaction.
Instruct diabetic patients to report increased levels of blood glucose.
Caution patient to avoid sudden position changes to prevent orthostatic hypotension.
Tell patient to report these symptoms to health care provider: Decrease in urinary output, jaundice, muscle cramps, weakness, nausea, blurred vision, or dizziness.
Instruct patient to drink 2 to 3 L/day of water unless contraindicated.
Advise patient that drug may cause drowsiness and to use caution while driving or performing other tasks requiring mental alertness.