Amiloride
Amiloride is a potassium-sparing diuretic (water pill) used alongside other diuretics in heart failure or high blood pressure to restore or protect healthy potassium levels.
🧬 Where this information comes from Click to expand
The clinical label records used on this page are FDA-filed Structured Product Labeling (SPL) retrieved through openFDA. We identified 5 clinical label sets within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. Forms, routes, brands, labelers, strengths, and NDC product-record counts are built separately from matching FDA National Drug Code Directory records. The linked DailyMed document is a representative official source for verification, not the page’s only clinical source. View the linked label on DailyMed →
Amiloride is a potassium-sparing diuretic (a water pill) that helps the kidneys hold on to potassium, used as an add-on to a thiazide or similar diuretic in heart failure or high blood pressure; it has been around since the mid-1980s and is available as a generic. Most people tolerate it well, and nausea, loss of appetite or a headache are the most likely complaints. Its boxed warning is high potassium (hyperkalemia), which can be fatal and is more likely with kidney problems, diabetes or older age, so regular potassium blood tests matter. Avoid potassium supplements and potassium-based salt substitutes unless your prescriber says otherwise.
Clinical pearls
- Take it with food, and keep taking your other diuretic, since amiloride is meant to work alongside it, not replace it.
- Never combine it with spironolactone or triamterene, and expect closer potassium checks with lisinopril, losartan or similar blood pressure medicines.
- A bout of vomiting, diarrhea or any illness that strains the kidneys is a reason to get potassium rechecked sooner.
- Tell whoever orders a glucose tolerance test (sugar-drink test) about amiloride; it should be stopped at least three days before.
⚠️ FDA Boxed Warning — the FDA’s strongest safety alert ▾
Amiloride can cause dangerously high potassium (hyperkalemia), which can be fatal if not corrected.
It happens in about 10% of people who take amiloride without another potassium-losing diuretic. The risk is higher in people with kidney problems, diabetes, and older adults. Combined with a thiazide diuretic in people without these problems, the risk drops to about 1 to 2%.
Warning signs include tingling, muscle weakness, fatigue, a slow heartbeat and, in severe cases, paralysis-like weakness or shock. Because symptoms may not appear early, regular potassium blood tests are essential.
Patient information guide A plain-language walkthrough of Amiloride, written from its FDA label.
What Amiloride is used for
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Amiloride is used as an add-on to other diuretics in these situations:
- Adjunctive treatment with thiazide or other potassium-losing diuretics in congestive heart failure or hypertension, to help restore normal potassium when it has become low (hypokalemia).
- Prevention of low potassium in people at particular risk, such as those taking digitalis or with significant heart rhythm problems.
- Rarely, alone, only when persistent low potassium has been documented and with close monitoring.
These uses apply to amiloride hydrochloride tablets taken by mouth.
How Amiloride works
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Amiloride is a potassium-conserving drug. It blocks sodium reabsorption in the later parts of the kidney tubules. This makes the tubes less able to push potassium and acid out into the urine, so more potassium stays in your body.
It works without needing the hormone aldosterone. Its own diuretic and blood-pressure effects are weak compared with thiazides.
Amiloride dosage
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Amiloride tablets are taken by mouth, usually once daily, with food. They are typically added to your existing diuretic.
- Your prescriber may adjust the amount based on potassium blood tests.
- In heart failure, need for it may be re-evaluated after initial fluid loss, and maintenance may be intermittent.
- Follow your prescriber and the pharmacy label.
Dosing details from the FDA-approved label
From the Amiloride prescribing information (“Dosage and Administration”). Doses are set by your prescriber for your product, condition, kidney function and age — never change a dose on your own.
- Adjunct to a kaliuretic diuretic for antihypertensive or diuretic therapy (added to the usual dosage of the kaliuretic diuretic)
- One 5 mg tablet daily added to the usual antihypertensive or diuretic dosage of a kaliuretic diuretic
- May be increased to 10 mg per day, if necessary
- If persistent hypokalemia is documented with 10 mg, the dose can be increased to 15 mg, then 20 mg, with careful monitoring of electrolytes
- Maximum: More than two 5 mg tablets daily usually are not needed, and there is little controlled experience with such doses.
- Administer with food.
- Congestive heart failure after an initial diuresis has been achieved
- Potassium loss may decrease and the need for amiloride hydrochloride should be re-evaluated
- Dosage adjustment may be necessary
- Maintenance therapy may be on an intermittent basis
- Administer with food.
- Amiloride hydrochloride used alone (see INDICATIONS)
- Starting dosage one 5 mg tablet daily
- May be increased to 10 mg per day, if necessary
- If persistent hypokalemia is documented with 10 mg, the dose can be increased to 15 mg, then 20 mg, with careful monitoring of electrolytes
- Maximum: More than two 5 mg tablets usually are not needed, and there is little controlled experience with such doses.
- Administer with food.
Read the label’s full dosing text
DOSAGE AND ADMINISTRATION Amiloride hydrochloride should be administered with food. Amiloride hydrochloride, one 5 mg tablet daily, should be added to the usual antihypertensive or diuretic dosage of a kaliuretic diuretic. The dosage may be increased to 10 mg per day, if necessary. More than two 5 mg tablets of amiloride hydrochloride daily usually are not needed, and there is little controlled experience with such doses. If persistent hypokalemia is documented with 10 mg, the dose can be increased to 15 mg, then 20 mg, with careful monitoring of electrolytes. In treating patients with congestive heart failure after an initial diuresis has been achieved, potassium loss may also decrease and the need for amiloride hydrochloride should be re-evaluated. Dosage adjustment may be necessary. Maintenance therapy may be on an intermittent basis. If it is necessary to use amiloride hydrochloride alone (see INDICATIONS ), the starting dosage should be one 5 mg tablet daily. This dosage may be increased to 10 mg per day, if necessary. More than two 5 mg tablets usually are not needed, and there is little controlled experience with such doses. If persistent hypokalemia is documented with 10 mg, the dose can be increased to 15 mg, then 20 mg, with careful monitoring of electrolytes.
Read the full Dosage and Administration section on DailyMed →
Amiloride side effects
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Amiloride is usually well tolerated. Common effects include:
Common side effects
- Nausea or loss of appetite
- Diarrhea or vomiting
- Abdominal pain, gas
- Headache
- Weakness or fatigue
- Dizziness
- Muscle cramps
- Mild skin rash
- Cough, shortness of breath
When to get medical help
- Muscle weakness, tingling or numbness (paresthesias), unusual fatigue, or a slow heartbeat can signal high potassium. Get medical help right away.
- Paralysis-like weakness in the arms or legs, or shock, can be signs of dangerously high potassium.
- Chest pain, palpitations or irregular heartbeat need prompt attention.
- Yellowing of the skin or eyes (jaundice) should be reported.
- Black or bloody stools or other signs of GI bleeding should be reported.
- Confusion, vision changes or severe dizziness should be reported.
Amiloride warnings and precautions
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- High potassium (hyperkalemia) can be fatal. It is more likely in kidney disease, diabetes and older age. Regular blood tests are needed.
- In people with diabetes, amiloride should be avoided if possible and monitored frequently.
- Use with caution in severely ill people at risk of acidosis, which can quickly raise potassium.
- Stop at least three days before glucose tolerance testing.
Amiloride interactions
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These can raise potassium or affect how amiloride works:
- Spironolactone or triamterene: should not be combined, since both hold on to potassium.
- Potassium supplements, salt substitutes, potassium-rich diet: can cause quick potassium rises.
- ACE inhibitors, angiotensin receptor blockers, cyclosporine, tacrolimus: raise high-potassium risk.
- Lithium: diuretics can cause lithium toxicity.
- NSAIDs: may reduce the diuretic effect.
- Indomethacin: both can raise potassium.
Interactions listed in the FDA-approved label
From the Amiloride prescribing information (“Drug Interactions”): what the manufacturer studied or reported to the FDA.
- Angiotensin-converting enzyme inhibitor: The risk of hyperkalemia may be increased. If concomitant use is indicated because of demonstrated hypokalemia, use with caution and with frequent monitoring of serum potassium.
- Angiotensin II receptor antagonist: The risk of hyperkalemia may be increased. If concomitant use is indicated because of demonstrated hypokalemia, use with caution and with frequent monitoring of serum potassium.
- Cyclosporine: The risk of hyperkalemia may be increased. If concomitant use is indicated because of demonstrated hypokalemia, use with caution and with frequent monitoring of serum potassium.
- Tacrolimus: The risk of hyperkalemia may be increased. If concomitant use is indicated because of demonstrated hypokalemia, use with caution and with frequent monitoring of serum potassium.
- Lithium: Diuretics reduce lithium's renal clearance and add a high risk of lithium toxicity. Lithium generally should not be given with diuretics. Read circulars for lithium preparations before use of such concomitant therapy.
- Non-steroidal anti-inflammatory agents: In some patients, an NSAID can reduce the diuretic, natriuretic, and antihypertensive effects of loop, potassium-sparing and thiazide diuretics. Observe the patient closely to determine if the desired effect of the diuretic is obtained.
- Indomethacin: Indomethacin and potassium-sparing diuretics, including amiloride hydrochloride, may each be associated with increased serum potassium levels. Consider the potential effects on potassium kinetics and renal function when these agents are administered concurrently.
Read the label’s full interactions text
Drug Interactions When amiloride hydrochloride is administered concomitantly with an angiotensin-converting enzyme inhibitor, an angiotensin II receptor antagonist, cyclosporine or tacrolimus, the risk of hyperkalemia may be increased. Therefore, if concomitant use of these agents is indicated because of demonstrated hypokalemia, they should be used with caution and with frequent monitoring of serum potassium. (See WARNINGS ). Lithium generally should not be given with diuretics because they reduce its renal clearance and add a high risk of lithium toxicity. Read circulars for lithium preparations before use of such concomitant therapy. In some patients, the administration of a non-steroidal anti-inflammatory agent can reduce the diuretic, natriuretic, and antihypertensive effects of loop, potassium-sparing and thiazide diuretics. Therefore, when amiloride hydrochloride 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 amiloride hydrochloride, 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.
Not a complete list. The label covers the interactions the manufacturer studied or reported, and our own interaction database does not cover every medicine either. Bring your full medication list, including vitamins and herbal products, to your pharmacist.
Before taking Amiloride
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- Do not use with high potassium, anuria, acute or chronic kidney insufficiency, or diabetic kidney disease.
- Do not use if allergic to amiloride.
- People with diabetes or reduced kidney function need frequent lab monitoring.
- Older adults have a higher risk of high potassium.
- Do not combine with other potassium-sparing drugs, potassium supplements or salt substitutes unless directed.
Amiloride overdose
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The most likely signs of too much are dehydration and electrolyte imbalance. There is no specific antidote. Treatment is stopping amiloride, close observation, and supportive care, with active steps to lower potassium if it is high. Seek emergency help if an overdose is suspected.
What Amiloride does in the body
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Amiloride conserves potassium and has weak water-pill and blood-pressure effects compared with thiazides. With a thiazide or loop diuretic, it reduces the extra magnesium lost in urine. It has little effect on kidney filtration rate or kidney blood flow.
How your body processes Amiloride
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Amiloride usually starts working within 2 hours of an oral dose. Effects on electrolytes peak at 6 to 10 hours and last about 24 hours. Blood levels peak in 3 to 4 hours, and the half-life is 6 to 9 hours. It is not broken down by the liver and is cleared unchanged, mainly in urine and stool.
How to store Amiloride
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Protect from moisture, freezing and excessive heat. Store at 20° to 25°C (68° to 77°F) .
Written from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →
Supplements & herbs that interact with Amiloride
143 supplements and herbal products have documented interactions with Amiloride in the licensed clinical database we use. Most are manageable — but your pharmacist should know about everything you take, including vitamins and herbals.
- Major · 4
- Moderate · 116
- Minor · 23
Educational information from a licensed clinical database (Natural Medicines) — see our data sources & update cadence. Not medical advice: an interaction being documented does not mean it will happen to you; do not start or stop medications or supplements without professional guidance.
Nutrient depletion considerations
Amiloride has been associated with lower levels of 1 nutrient in the clinical literature. This does not mean a deficiency will occur — it means these may be worth discussing with your pharmacist or healthcare provider, especially with long-term use.
Educational information from a licensed clinical database (Natural Medicines) — not medical advice. Do not start or stop medications or supplements without professional guidance.
Amiloride: pharmacist answers to common questions
Quick, plain-English answers to the questions patients ask most about Amiloride — the kind of thing our pharmacy team would talk through with you at the counter.
Why was I prescribed amiloride?
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How should I take it?
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What side effects should I expect?
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What's the serious risk I should know about?
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Can I use salt substitutes or potassium supplements?
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Do other medicines matter?
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Is Amiloride available over the counter?
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When was Amiloride first available?
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Who makes Amiloride?
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Answers drafted from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →
More about Amiloride on HelloPharmacist
Amiloride forms and strengths (how it comes)
Amiloride is available in 1 form. Different forms and brands can have different approved uses, doses, schedules, and directions. Follow the instructions for your exact product, and do not switch forms without guidance from your prescriber or pharmacist.
Tablet
How this form is used
- Amiloride hydrochloride tablets are used as add-on treatment with thiazide or other potassium-losing diuretics in congestive heart failure or hypertension.
- Amiloride hydrochloride tablets help restore normal potassium or prevent low potassium in at-risk patients.
- Amiloride hydrochloride tablets are taken by mouth with food.
- Amiloride hydrochloride tablets are usually added to the dose of the potassium-losing diuretic and adjusted with electrolyte monitoring.
Amiloride on the U.S. market: products, makers and brands
How Amiloride appears in the FDA’s National Drug Code Directory — including its dosage forms, strengths, brand names, manufacturers, and FDA-listed product records. These are directory records, not sales or prescription volume.
3 companies list 3 Amiloride product records with the FDA, mostly as tablet; the earliest marketing or approval year on record is 1981. Brand names on the directory include Midamor, amiloride hydrocloride; the rest are generics.
Also listed with the FDA, not a patient dose form: Powder (4) — bulk drug substance sold to compounders/manufacturers and multi-item kits. These aren’t counted in the dose-form total above.
Share of FDA-listed product records by manufacturer — FDA National Drug Code Directory. Record counts are not sales or prescription volume.
How widely Amiloride is used (Medicaid data)
A general measure of how commonly Amiloride is prescribed, based on Medicaid — one of the largest public drug programs. The figure below is prescriptions filled in Q1–Q4 2025, summed across every form and brand of the drug.
Think of this as a proxy for how widely Amiloride is used, drawn from freely available public data. Medicaid is just one program — these numbers don’t include Medicare, other government coverage, or commercial and cash-pay prescriptions, so real-world use is higher than what’s shown here.
How commonly is Amiloride prescribed? Of the 1,601 medications we measure, Amiloride ranks #787 by Medicaid prescriptions — more than 51% of them.
Utilization by Amiloride product
Pick a product to see its own Medicaid numbers. Each chip is one clinical product — a specific strength & dosage form as defined by RxNorm — with brand-name and generic versions combined.
amiloride hydrochloride 5 MG Oral Tablet
Summed across the 3 of 12 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 977880
Shares are of the Medicaid prescriptions shown here. Product grouping follows RxNorm (the National Library of Medicine’s drug terminology), so “one product” means one strength & dosage form regardless of manufacturer. Dollar figures are gross Medicaid reimbursement before mandatory rebates — rebates (often large, especially for brand-name drugs) are confidential, so actual net cost to Medicaid is lower than shown.
Source: Medicaid State Drug Utilization Data (CMS), aggregated by generic ingredient — summed across every NDC (all brands, strengths, salt forms and dosage forms) of Amiloride, and across all states and both fee-for-service and managed-care claims. A general popularity signal; it excludes Medicare, commercial insurance and cash prescriptions, so it is not total U.S. use. Based on the 3 of 12 listed Amiloride NDCs with Medicaid activity.
Compare Amiloride products
A representative set of FDA-listed product records for Amiloride — across manufacturers, strengths, and dosage forms, grouped by form with each product’s manufacturer and how the FDA approved it. The same medicine may be made and packaged by different companies, so a single drug can have many directory entries. (It’s also why a refill can look different — a new shape, color, or box — even though it contains the same medication.)
| Strength | Route | Manufacturer / Labeler | Category ⓘ | Details |
|---|---|---|---|---|
| 💊Tablet | ||||
| 5 mg | Oral | Endo USA, Inc. | ANDA | View NDC → |
| 5 mg | Oral | Padagis US LLC | NDA AUTHORIZED GENERIC | View NDC → |
| 5 mg | Oral | Sigmapharm Laboratories, LLC | ANDA | View NDC → |
Showing 3 of 3 products — FDA National Drug Code Directory.
Amiloride side effects reported to the FDA (FAERS)
After a medicine reaches the market, patients, doctors and drugmakers can send the FDA reports of problems they think may be linked to it. Here’s what’s been reported for Amiloride — a signal of what to watch for, not proof the drug caused it.
Source: openFDA, from the FDA Adverse Event Reporting System (FAERS). These are voluntary reports — they don’t prove the drug caused the effect, and counts reflect how often something was reported, not how often it actually happens. Reports also often name the very problem the medicine is taken for — a common reason to file one is that the drug didn’t help — so for a pain reliever you may see “pain” high on the list; that points to why the report was filed, not to the drug causing the symptom. This counts every report that lists Amiloride in any role, so the total runs higher than the FDA’s official dashboard, which counts only cases where the drug is the suspect. For the authoritative figures, see the FDA FAERS Public Dashboard. Always talk to your pharmacist or doctor.
Amiloride FDA approval history
How Amiloride went from FDA review to the pharmacy shelf — the key milestones in its regulatory journey.
Source: Drugs@FDA.
Amiloride recall history
A recall is when a specific batch of a medicine is pulled from the market — usually a manufacturing issue, not a problem with the drug itself. Class I is most serious, Class III least.
The FDA’s enforcement reports list no Amiloride recalls since July 2021.
✅No Amiloride recalls on record since July 2021Source: FDA enforcement (recall) reports, via openFDA; our copy was last updated Sep 24, 2026.
RxNorm Concept Web — From Ingredient to Every Form and Strength
This page starts with one ingredient concept (IN). The branches below show its dose-form concepts (SCDF), then the available clinical drug and strength concepts (SCD). Combination products remain separate concepts with their own pages.
RxCUI 644 2 dose forms · 2 strengths
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Dose form (SCDF) Oral Solution RxCUI 370849No current FDA listingClinical drug / strength (SCD) hydrochloride 1 MG/MLRxCUI 977887 -
Dose form (SCDF) Oral Tablet RxCUI 370564In current FDA listingsClinical drug / strength (SCD) hydrochloride 5 MGRxCUI 977880
Look up RxCUI 644 in the RxCUI Atlas →
RxNorm is the U.S. National Library of Medicine’s normalized drug vocabulary. Its concept hierarchy can include forms that are not currently marketed; the status on each branch compares that concept with current FDA listings. RxCUIs identify vocabulary concepts, not individual packages or manufacturers.
Amiloride supply and shortage status
Whether Amiloride is in short supply in the U.S. right now, plus any shortage history the FDA has on record. A shortage usually reflects a manufacturing or demand issue — not a safety problem with the drug.
Source: openFDA, from the FDA Drug Shortages database.
💵 What Amiloride costs pharmacies (NADAC benchmark)
The national average invoice price pharmacies pay for the drug itself, from CMS's NADAC survey (data as of Sep 30, 2026). This is a supply-cost benchmark — not a retail price and not what you'd pay at the counter.
| Form | Strength | Pharmacy acquisition benchmark | |
|---|---|---|---|
| Tablet · Oral | 5 mg | $0.190 per tablet | NDC details & price history |
Source: CMS National Average Drug Acquisition Cost (NADAC), a survey of retail pharmacy invoice prices. Benchmarks shown are the range across package sizes of a representative product for each form and strength — other manufacturers' products may differ.
Amiloride brand names
Amiloride is sold under 2 brand names in the FDA directory — Midamor, amiloride hydrocloride. A brand and its generic contain the same active ingredient; the brand name belongs to one company's product.
Who makes Amiloride: manufacturers and labelers
3 companies list Amiloride products with the FDA. By number of product records, the largest are Endo USA, Inc., Padagis US LLC, Sigmapharm Laboratories, LLC. Labelers include manufacturers and repackagers; the product in your bottle depends on which one your pharmacy stocks.
Amiloride drug class (RxNorm)
Amiloride belongs to the Potassium-sparing Diuretic class.
Classified by RxNorm RxClass — the U.S. National Library of Medicine's standardized drug-classification service (Established Pharmacologic Class from the FDA, the ATC drug family from the WHO, and mechanism of action). Reference only, not medical advice.
Sources for this Amiloride page
Core label, product, RxNorm, safety, and utilization data on this page come from the sources identified below. AI-written, editorial, and licensed sections are labeled separately.
How this page is built
HelloPharmacist combines public FDA and NLM records and does not author the underlying clinical facts. The plain-language sections are written with AI from the FDA-approved label text and reviewed by our pharmacy team before publication. Padagis US LLC is the representative DailyMed label linked for verification and dates. This is general education, not medical advice: always talk to your doctor or pharmacist about your own medicines. How we build and review drug pages →