The drug Amiloride belongs to the group of potassium-sparing diuretics. The main indications for its use are arterial hypertension, heart failure, coronary heart disease and associated edema. The drug is taken orally as a tablet or capsule.
What is amiloride?
Amiloride is a drainage drug that is primarily prescribed for arterial hypertension, heart failure, coronary heart disease (CHD) and edema. The active ingredient amiloride can also be used off-label for inhalation in lung diseases, but has not yet been officially approved for this purpose.
The prescription drug is available in tablet and capsule form. It is common to always give amiloride in combination with an additional diuretic - usually hydrochlorothiazide. Diuretics like amiloride work through the kidneys, where they stimulate urine production and help remove excess water from the body. In addition, they wash out salts such as potassium. Both reduce blood pressure and thus relieve the heart.
Due to its chemical properties, the active ingredient amiloride is a pyrazine derivative. As a light-sensitive material, amiloride should be stored in the dark.
Pharmacological effect
Amiloride works best in combination with another diuretic. In most cases, the therapy uses an active ingredient combination of amiloride and a thiazide diuretic such as hydrochlorothiazide.
Alternatively, there is the combination of amiloride with a loop diuretic. The two active ingredients serve to lower high blood pressure and relieve the heart. Amiloride acts via the kidneys, where it inhibits the epithelial aldosterone-dependent sodium channel located in the late distal tubule of the renal nephron. This means that a smaller amount of sodium is reabsorbed and, as a result, correspondingly less potassium is excreted in exchange for sodium. In this way, potassium ions are saved.
The potassium-sparing effect created in this way can increase the level of potassium in the blood so much that it leads to hyperkalemia, a potentially life-threatening electrolyte disorder. In particular with simultaneous therapy with ACE inhibitors or spironolactone, the risk of this is increased and the blood potassium level must be closely monitored. An increased blood potassium level can be a contraindication for the administration of amiloride.
The diuretic effect of amiloride washes away water retention from the tissue. Since the body also loses salts, the prescription of amiloride is particularly suitable for patients in whom a loss of potassium must be avoided for the duration of the intended fluid excretion.
Amiloride has good bioavailability, is not metabolized and later largely excreted in the urine.
Medical application & use
The combination preparation of amiloride with another diuretic from the group of thiazides such as hydrochlorothiazide is used to treat high blood pressure, heart failure, coronary heart disease and fluid accumulation - edema - in the tissue. Amiloride leads to increased urine excretion via the kidneys.
The water retention flushed out in the process lowers blood pressure and thus relieves the heart. However, since salts also leave the body during this process, a loss of potassium must be avoided. As a potassium-sparing drug, amiloride is ideally suited for this therapy.
The dosage and duration of treatment depends on the type of disease and its severity. Therapy for hypertension usually starts with half a tablet per day. During long-term therapy, the dose is almost always reduced to a quarter of a tablet a day. For edema caused by heart failure, therapy begins with half a tablet or a whole tablet daily. If necessary, the dose can be increased to a maximum of two tablets per day.
Risks & side effects
When taking amiloride and its combination active ingredients, undesirable side effects such as:
- Nausea to vomiting
- Loss of appetite
- Diarrhea
- Constipation
- Electrolyte disorders
- Cardiac arrhythmias
- a headache
- confusion
Amiloride is contraindicated in certain diseases and in special life situations. Which includes:
- Hyposensitivity to sulfonamides (due to combination with hydrochlorothiazide)
- Hyperkalemia and other disorders of the electrolyte balance
- Cardiac arrhythmias
- Kidney dysfunction
- Liver dysfunction
- pregnancy
- Lactation
Children should also be excluded from treatment with amiloride.
