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Amiloride Hydrochloride / Hydrochlorothiazide

Pronouncation: (Uh-MILL-oh-ride HIGH-droe-KLOR-ide/high-droe-klor-oh-THIGH-uh-zide)
Class: Diuretic combination

Trade Names:
- Tablets 5 mg amiloride/50 mg hydrochlorothiazide

Apo-Amilzide (canada)
Moduret (canada)
Novamilor (canada)
Nu-Amilzide (canada)

Mechanism of Action



Interferes with sodium reabsorption at distal tubule, resulting in increased water and sodium excretion and decreased potassium excretion.

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Increases chloride, sodium, and water excretion by interfering with transport of sodium ions across renal tubular epithelium.

Indications and Usage

Treatment of hypertension or congestive heart failure in patients who develop hypokalemia when thiazide or other kaliuretic diuretics are used alone, or in patients in whom maintenance of normal serum potassium levels is clinically important (eg, digitalized patients); alone or as adjunctive treatment with other antihypertensive agents.


Hyperkalemia (serum potassium levels greater than 5.5 mEq/L); concurrently with other potassium-sparing diuretics (eg, spironolactone), potassium supplements (including potassium-rich diet) except in severe or refractory cases of hypokalemia; impaired renal function; sensitivity to any components of product.

Dosage and Administration


PO 1 to 2 tablets (5 mg amiloride/50 mg hydrochlorothiazide) daily with meals.


Store tablets at controlled room temperature (59° to 86°F). Protect from moisture, freezing, and excessive heat.

Drug Interactions

Amiloride ACE inhibitors (eg, captopril)

May result in severely elevated potassium levels.

Potassium preparations

May severely increase serum potassium levels, possibly resulting in cardiac arrhythmias or cardiac arrest. Do not coadminister.

Hydrochlorothiazide Bile acid sequestrants

May reduce thiazide absorption; give thiazide at least 2 h before sequestrant.


May cause hyperglycemia.

Digitalis glycosides

Diuretic-induced hypokalemia and hypomagnesemia may lead to digitalis-induced arrhythmias.


Renal excretion of lithium may be reduced.

Loop diuretics (eg, furosemide)

Synergistic effects may occur, resulting in profound diuresis and serious electrolyte abnormalities.

Sulfonylureas (eg, chlorpropamide)

Hypoglycemic effect of sulfonylurea may be decreased, necessitating an increase in sulfonylurea dosage.

Laboratory Test Interactions

Hydrochlorothiazide may decrease serum protein-bound iodine levels without signs of thyroid disturbances. May cause diagnostic interference of serum electrolyte levels, blood and urine glucose levels, serum bilirubin levels, and serum uric acid levels.

Adverse Reactions


Arrhythmia, tachycardia, palpitations (amiloride).


Headache, fatigue, tiredness, weakness, dizziness, encephalopathy, tremors, decreased libido (amiloride); restlessness (hydrochlorothiazide).


Mild skin rash, pruritus, alopecia (amiloride); urticaria, purpura (hydrochlorothiazide).


Increased ocular pressure, tinnitus (amiloride); transient blurred vision, xanthopsia (hydrochlorothiazide).


Nausea, anorexia, GI and abdominal pain, flatulence, activation of peptic ulcer, dyspepsia, heartburn, dry mouth (amiloride); pancreatitis, cramping, GI irritation, sialadenitis (hydrochlorothiazide).


Bladder spasm, polyuria, urinary frequency (amiloride); interstitial nephritis (hydrochlorothiazide).


Aplastic anemia, neutropenia (amiloride); agranulocytosis, leukopenia, hemolytic anemia, thrombocytopenia (hydrochlorothiazide).




Hyperkalemia, hyperglycemia, glucosuria, hyperuricemia (hydrochlorothiazide).


Shortness of breath, cough (amiloride); respiratory distress, including pneumonitis and pulmonary edema (hydrochlorothiazide).


Leg pain, painful extremities, neck/shoulder ache, fatigue, itching (amiloride); anaphylactic reactions, necrotizing angiitis, photosensitivity, fever (hydrochlorothiazide).




Ensure that serum electrolytes, BUN, and creatinine are monitored periodically.


Category B .


Amiloride: undetermined; hydrochlorothiazide: excreted in breast milk.


Safety and efficacy not established.


Hyperkalemia may occur. The risk of hyperkalemia may be increased in patients with renal impairment or diabetes mellitus. If possible, avoid use in patients with renal impairment or diabetes mellitus.



Dehydration, electrolyte imbalance (eg, hyperkalemia), electrolyte depletion (hypokalemia, hypochloremia, hyponatremia).

Patient Information

  • Advise patient to take prescribed dose once daily in the morning with food.
  • Inform patient that drug controls, but does not cure, hypertension and to continue taking medication as prescribed even when BP is not elevated.
  • Caution patient not to change the dose or stop taking unless advised by health care provider.
  • Instruct patient to continue taking other BP medications as prescribed by health care provider.
  • Instruct patient in BP and pulse measurement skills.
  • Advise patient to monitor and record BP and pulse at home and to inform health care provider should abnormal measurements be noted. Also, advise patient to take record of BP and pulse to each follow-up visit.
  • Instruct patient to lie or sit down if experiencing dizziness or lightheadedness when standing.
  • Caution patient that inadequate fluid intake, excessive perspiration, diarrhea, or vomiting can lead to excessive fall in BP, resulting in lightheadedness or fainting.
  • Instruct diabetic patient to monitor blood glucose more frequently when drug is started or dose is changed and to inform health care provider of significant changes in readings.
  • Caution patient to avoid unnecessary exposure to UV light (sunlight, tanning booths) and to use sunscreen and wear protective clothing when exposed to UV light to avoid photosensitivity reaction.
  • Emphasize to hypertensive patient importance of other modalities on BP: weight control, regular exercise, smoking cessation, and moderate intake of alcohol and salt.
  • Instruct patient to stop taking drug and immediately report any of these symptoms to health care provider: abnormal skin sensations, muscle weakness, or slow pulse.