Amiloride: Price, Dosage & Where to Buy

Amiloride is a potassium-sparing diuretic, a medicine that helps the body retain potassium while passing salt and water into urine. It is mainly prescribed alongside other diuretics to prevent or correct low blood potassium in people with heart failure or high blood pressure. Amiloride requires a prescription in the United Kingdom and is rarely used alone.

Amiloride is used alongside thiazide diuretics or other diuretics that can cause potassium loss in people with congestive heart failure or high blood pressure. It helps restore normal blood potassium when another diuretic has lowered it. It can also help prevent low potassium in people who would be at particular risk, including those receiving digitalis medicines or those with significant abnormal heart rhythms.

Amiloride adds little extra fluid-removing or blood-pressure-lowering effect to a thiazide diuretic. It is rarely used alone, and use on its own is reserved for documented, persistent low potassium with close blood monitoring.

Potassium-sparing diuretics act in the kidneys, where salt, water and minerals are handled before urine leaves the body. Amiloride reduces the movement of sodium, a component of salt, back into the blood. Some extra sodium and water then leave through the urine.

This action also reduces the amount of potassium lost in urine, helping the body retain it. Because potassium can build up rather than simply return to normal, blood monitoring is needed. Amiloride has a relatively weak fluid-removing effect.

The label lists oral tablets containing 5 mg of amiloride hydrochloride. The usual starting dose is 5 mg daily alongside the usual treatment with a diuretic that causes potassium loss. The label lists an increase to 10 mg per day if necessary.

The label lists further increases to 15 mg, then 20 mg, for documented low potassium that persists with 10 mg, with careful monitoring of blood minerals. The label lists 5 mg daily as the starting dosage when amiloride must be used alone, with an increase to 10 mg per day if necessary. Administration with food is specified.

Higher doses are usually unnecessary, and controlled experience with them is limited. In congestive heart failure, potassium loss may decrease after the initial removal of excess fluid, so the need for amiloride should be reviewed.

Dosage adjustment may be necessary, and maintenance treatment may be intermittent. Treatment decisions depend on the reason for use and blood monitoring.

If a dose is missed, the usual pharmacy advice is to resume the prescribed schedule rather than double a dose to make up for it. If it is nearly time for the next dose, the missed dose is normally left out. A pharmacist can advise if the timing is unclear, particularly when treatment follows an intermittent schedule.

There are no adequate, well-controlled studies of amiloride in pregnant women. Animal studies found no evidence of harm to the developing fetus in some studies, but other studies found toxicity and reduced offspring growth and survival. Amiloride crossed the placenta in animals.

The label states that use during pregnancy should be limited to cases where it is clearly needed. The label does not specify breastfeeding information; discuss this with a doctor or pharmacist.

Store at controlled room temperature, 15° to 30°C, in a tight, light-resistant container. Keep the medicine out of the sight and reach of children, and follow the storage directions on the dispensing label.