Amiloride

Basic amiloride information

• INN (international nonproprietary name): amiloride.
• Brand names available in the United Kingdom: Amiloride Hydrochloride (generic) 5 mg tablets.
• ATC code: C03DB01 (Potassium‑sparing diuretics, plain).
• Forms and strengths: tablets, typically 5 mg; combination products with thiazide diuretics are marketed for hypertension/heart failure.
• Manufacturers in the United Kingdom: Mylan, Teva, Bristol Labs.
• Registration status in the United Kingdom: Listed with the MHRA as Amiloride Hydrochloride and classified as a prescription medicine (POM).
• OTC / Rx classification: prescription-only medicine (POM) in the UK.

Legal status and availability in the UK

In our online pharmacy, amiloride is available without a prescription, with discreet delivery to the United Kingdom in 9–21 days.

Clinical effectiveness in the UK

Are patients likely to avoid low potassium when started on amiloride?

Amiloride helps prevent diuretic‑induced hypokalaemia, particularly when added to thiazide therapy.

Combination regimens reduce the need for separate potassium supplements in many patients.

Efficacy signals are strongest in targeted groups such as people with saline‑retaining oedema or resistant oedema related to heart failure.

There are no modern large randomised controlled trials demonstrating a hard mortality benefit for amiloride versus alternatives within the same timeframe.

Response is assessed by change in serum potassium, oedema and blood pressure.

Indications and expanded uses

What is amiloride licensed to treat and when is it used off‑label?

MHRA product information lists amiloride as a prescription‑only diuretic for oedema and as adjunct diuretic therapy.

UK primary‑care guidance commonly favours amiloride to counteract thiazide‑induced hypokalaemia and for refractory oedema in heart failure under specialist oversight.

Rare disease case series support specialist use in Liddle’s syndrome and certain renal tubular disorders, but this remains off‑label and usually consultant‑led.

Off‑label prescribing in the NHS is documented with shared‑care letters and explicit consent, and GPs generally do not initiate specialist uses without consultant guidance.

Typical starting regimens are 5–10 mg once daily with maximums noted in product information and specialist guidance; exact individual doses depend on indication and renal function.

The table below contrasts MHRA‑approved indications with common off‑label specialist uses.

Composition and brand landscape

How will patients recognise amiloride at the pharmacy?

Most amiloride in the UK is supplied as single‑ingredient 5 mg tablets, often labelled as Amiloride Hydrochloride and supplied in 28 or 56 tablet packs.

Combination products containing a thiazide remain common across antihypertensive formularies and are widely used to reduce thiazide‑induced potassium loss.

UK market manufacturers listed include Mylan, Teva and Bristol Labs; supply is largely generic.

Patients often receive the generic INN name on the label rather than a brand name, and pharmacists commonly explain the difference when switching generics to reduce confusion.

Contraindications and special precautions

Who must not take amiloride and who needs extra checks?

Absolute contraindications include known hypersensitivity, anuria, acute or chronic severe renal impairment, Addison’s disease and baseline potassium greater than 5.5 mmol/L.

Relative contraindications requiring close monitoring include mild to moderate renal dysfunction, diabetes mellitus, hepatic dysfunction and advanced age.

Hyperkalaemia risk is increased when amiloride is combined with ACE inhibitors or ARBs, and in diabetics with impaired renal function.

UK clinicians routinely check baseline U&Es and eGFR before initiation and arrange frequent early monitoring thereafter.

Elderly patients typically start at lower doses and have closer follow‑up due to higher susceptibility to electrolyte disturbances.

Driving and alcohol advice is pragmatic: there is no blanket driving ban, but patients should be warned about dizziness and advised to avoid driving if symptomatic.

Pregnancy and breastfeeding use is generally avoided without specialist input and documented risk–benefit discussion.

Hyperkalaemia is the most important serious adverse effect.

Dosage guidelines

What starting dose should a patient expect and how is monitoring scheduled?

NHS formularies and product information recommend starting amiloride at 5 mg once daily for most adults, with some regimens offering 5–10 mg daily depending on response.

For congestive heart failure, doses can be titrated cautiously up to 20 mg per day in divided doses under close monitoring.

When combined with a thiazide, a common approach is to start 5 mg amiloride alongside the standard thiazide dose such as hydrochlorothiazide 50 mg where appropriate.

Typical monitoring schedule recorded in GP records is baseline U&Es, repeat at 1–2 weeks, again at 1 month and at 3 months, then periodically as indicated by renal function and comorbidity.

Elderly patients and those with reduced eGFR receive conservative dosing and more frequent checks.

Children under 18 are not routinely recommended for amiloride treatment and paediatric dosing is specialist‑determined.

Missed doses should be taken as soon as remembered unless close to the next dose, and overdose requires urgent medical attention for possible hyperkalaemia and cardiac effects.

Interactions overview

Which medicines raise the biggest safety flags with amiloride?

Pharmacodynamic interactions are the chief concern: ACE inhibitors, ARBs, potassium supplements and other potassium‑sparing agents markedly increase the risk of hyperkalaemia.

Aldosterone antagonists such as spironolactone or eplerenone also raise potassium risk if co‑prescribed and generally require specialist oversight.

NSAIDs can reduce renal perfusion and precipitate adverse renal and electrolyte events when combined with diuretics.

UK pharmacists routinely check electronic prescriptions and counsel patients on avoiding over‑the‑counter NSAIDs and potassium‑containing salt substitutes without checking with their GP or pharmacist.

Dietary interactions are limited, but large unsupervised changes to potassium intake should prompt a blood test.

Practical advice for patients: bring a full medication list to every pharmacy consultation and review OTC use with the pharmacist.

Comparable medicines and preferences

How does amiloride compare with other potassium‑sparing options?

Amiloride sits in the same ENaC class as triamterene and is distinct in mechanism from aldosterone antagonists such as spironolactone and eplerenone.

Compared with spironolactone, amiloride tends to avoid endocrine side effects such as gynaecomastia and sexual dysfunction, though it may be less potent in aldosterone‑mediated conditions.

Triamterene is a close alternative mechanistically, while spironolactone is favoured in heart‑failure management where outcome data support its use.

Clinicians choose based on comorbidity: amiloride is selected to prevent thiazide‑related hypokalaemia or when spironolactone is contraindicated.

Monitoring intensity is similar across potassium‑sparing agents, centred on potassium and renal function checks.

Amiloride’s generic supply from multiple manufacturers supports formulary inclusion for specific indications.

Pros and cons checklist for clinicians: mechanism, potassium effect, monitoring needs and side‑effect profile should guide choice.

Frequently asked questions

1. Can I take amiloride with ACE inhibitors or ARBs?

Combination raises hyperkalaemia risk and should only be used with specialist oversight and strict monitoring.

2. How often are blood tests needed?

Baseline U&Es are required, with an early check within 1–2 weeks after starting or changing dose, then at 1 month and 3 months and thereafter as indicated by renal function.

3. Can I stop suddenly?

Do not stop without GP advice; sudden cessation may change fluid balance and blood pressure and should be managed by the prescriber.

4. Is it safe in pregnancy?

Generally avoided in pregnancy and breastfeeding; specialist obstetric advice is required for individual risk‑benefit assessment.

Legal status reminder: Amiloride is a prescription medicine (POM) in the UK and urgent symptoms such as muscle weakness or palpitations require prompt medical contact via GP or NHS 111.

Guidelines for proper use

What should pharmacists check and tell patients before dispensing amiloride?

Confirm baseline renal function and serum potassium (eGFR and U&Es) before initiation and document a monitoring schedule in the patient record.

Ask about all current medicines including OTC NSAIDs and potassium supplements, and instruct patients to bring a full list to pharmacy consultations.

Explain the signs of hyperkalaemia clearly: muscle weakness, palpitations and unexplained fatigue should prompt urgent contact with GP or NHS 111.

Provide stepwise patient instructions: usual dose, what to do if a dose is missed, and when to seek urgent care for symptoms suggestive of electrolyte disturbance.

Use the NHS app or practice phone messaging to remind patients of blood tests and to share results when available.

Pharmacists should document counselling on interactions with ACE inhibitors, ARBs and potassium supplements and flag the need for early post‑initiation U&Es.

Monitoring terms: U&Es = urea and electrolytes; eGFR = estimated glomerular filtration rate.

For practical leaflets include contact points: GP surgery, NHS 111 and the dispensing pharmacy for routine queries.

Delivery across the United Kingdom