Reviewed on 3/30/2022

What Is Amiloride and How Does It Work?

Amiloride is a prescription medication used for the treatment of congestive heart failure, hypertension, and Thiazide-induced hypokalemia.

  • Amiloride is available under the following different brand names: Caldolor, NeoProfen

What Are Dosages of Amiloride?

Adult and pediatric dosage


  • 5mg

Congestive Heart Failure

Adult dosage

  • 5-10 mg/day orally every day OR divided every 12 hours


Adult dosage

  • 5-10 mg/day orally every day OR divided every 12 hours

Thiazide-Induced Hypokalemia

Adult dosage

  • 5-10 mg/day orally every day OR divided every 12 hours

Geriatric dosage

  • 5-10 mg/day orally every day OR every other day
  • Maximum dosage limit: 20 mg orally every day; 40 mg orally every day has been used

Dosage Considerations – Should be Given as Follows: 

  • See “Dosages”

What Are Side Effects Associated with Using Amiloride?

Common side effects of Amiloride include:

  • nausea,
  • vomiting,
  • stomach or abdominal pain,
  • loss of appetite,
  • gas,
  • diarrhea,
  • headache,
  • dizziness,
  • skin rash,
  • weakness,
  • fatigue,
  • constipation,
  • muscle cramps,
  • dizziness,
  • cough,
  • shortness of breath, and
  • impotence.

Serious side effects of Amiloride include:

  • increased thirst,
  • decreased urination,
  • heavy sweating, or hot and dry skin,
  • tremors, confusion, loss of consciousness,
  • jaundice (yellowing of the skin or eyes),
  • high potassium--tiredness, numbness or tingling, slow or unusual heart rate, muscle weakness or limp feeling; or
  • low levels of sodium in the body--headache, confusion, slurred speech, severe weakness, vomiting, loss of coordination, feeling unsteady.

Rare side effects of Amiloride include:

  • none 
This is not a complete list of side effects and other serious side effects or health problems that may occur as a result of the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may report side effects or health problems to FDA at 1-800-FDA-1088.

What Other Drugs Interact with Amiloride?

If your medical doctor is using this medicine to treat your pain, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider, or pharmacist first.

  • Amiloride has severe interactions with no other drugs.
  • Amiloride has serious interactions with the following drugs:
  • Amiloride has moderate interactions with at least 138 other drugs.
  • Amiloride has minor interactions with at least 34 other drugs.

This information does not contain all possible interactions or adverse effects. Visit the RxList Drug Interaction Checker for any drug interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you and share this information with your doctor and pharmacist. Check with your health care professional or doctor for additional medical advice, or if you have health questions, concerns.

What Are Warnings and Precautions for Amiloride?


  • Hypersensitivity to amiloride
  • Hyperkalemia (K+ above 5.5 mEq/L [5.5 mmol/L])
  • Concomitant use with K+-sparing diuretic, or K supplementation
  • Impaired renal function (Scr above 1.5 mg/dL [132.6 umol/L], or BUN above 30 mg/dL [10.7 mmol/L]) diabetes

Effects of drug abuse

  • None

Short-Term Effects

  • See “What Are Side Effects Associated with Using Amiloride?”

Long-Term Effects

  • See “What Are Side Effects Associated with Using Amiloride?”


  • Hyperkalemia
    • The risk of hyperkalemia may be increased when potassium-conserving agents, including amiloride hydrochloride, are administered concomitantly with an angiotensin-converting enzyme inhibitor, an angiotensin II receptor antagonist, cyclosporine, or tacrolimus
    • Warning signs or symptoms of hyperkalemia include paresthesias, muscular weakness, fatigue, flaccid paralysis of the extremities, bradycardia, shock, and ECG abnormalities; monitoring of the serum potassium level is essential because mild hyperkalemia is not usually associated with an abnormal ECG
    • When abnormal, the ECG in hyperkalemia is characterized primarily by tall, peaked T waves or elevations from previous tracings; there may also be lowering of the R wave and increased depth of the S wave, widening and even disappearance of the P wave, progressive widening of the QRS complex, prolongation of the PR interval, and ST depression
    • If hyperkalemia occurs the drug should be discontinued immediately; if serum potassium level exceeds 6.5 mEq per liter, active measures should be taken to reduce it; such measures include the intravenous administration of sodium bicarbonate solution or oral or parenteral glucose with a rapid-acting insulin preparation; if needed, a cation exchange resin such as sodium polystyrene sulfonate may be given orally or by enema; patients with persistent hyperkalemia may require dialysis
  • Diabetes Mellitus
    • In diabetic patients, hyperkalemia has been reported with the use of all potassium-conserving diuretics, including amiloride hydrochloride, even in patients without evidence of diabetic nephropathy; therefore, amiloride should be avoided, if possible, in diabetic patients and, if it is used, serum electrolytes and renal function must be monitored frequently; amiloride should be discontinued at least 3 days before glucose tolerance testing
  • Metabolic or Respiratory Acidosis
    • Antikaliuretic therapy should be instituted only with caution in severely ill patients in whom respiratory or metabolic acidosis may occur, such as patients with cardiopulmonary disease or poorly controlled diabetes
    • If therapy is administered to these patients, frequent monitoring of acid-base balance is necessary; shifts in acid-base balance alter the ratio of extracellular/intracellular potassium, and the development of acidosis may be associated with rapid increases in serum potassium levels
    • In patients with renal disease, diuretics may precipitate azotemia; cumulative effects of the components of amiloride hydrochloride may develop in patients with impaired renal function; if renal impairment becomes evident discontinue therapy
  • Drug interaction overview
    • In some patients, the administration of a non-steroidal anti-inflammatory agent can reduce the diuretic, natriuretic, and antihypertensive effects of loop and potassium-sparing diuretics
    • When amiloride and non-steroidal anti-inflammatory agents are used concomitantly, the patient should be observed closely to determine if the desired effect of the diuretic is obtained
    • Since indomethacin and potassium-sparing diuretics, including this product, may each be associated with increased serum potassium levels, the potential effects on potassium kinetics and renal function should be considered when these agents are administered concurrently

Pregnancy and Lactation

  • Teratogenicity studies in rabbits and mice given 20 and 25 times maximum human dose, respectively, revealed no evidence of harm to the fetus, although studies showed that the drug crossed the placenta in modest amounts; reproduction studies in rats at 20 times the expected maximum daily dose for humans showed no evidence of impaired fertility
  • At approximately 5 or more times the expected maximum daily dose for humans, some toxicity was seen in adult rats and rabbits and a decrease in rat pup growth and survival occurred
  • Lactation
    • Studies in rats have shown that amiloride is excreted in milk in concentrations higher than those found in blood, but it is not known whether amiloride hydrochloride is excreted in human milk
    • Because of the potential for serious adverse reactions in nursing infants, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother
Medscape. Amiloride.

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