Amiloride

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Amiloride
Systematic (IUPAC) name
3,5-diamino-6-chloro-N-(diaminomethylene)pyrazine-2-carboxamide
Identifiers
CAS number	2016-88-8
ATC code	C03DB01
PubChem	16231
DrugBank	APRD00790
Chemical data
Formula	C6H8ClN7O
Mol. mass	229.627 g/mol
Pharmacokinetic data
Bioavailability	Readily absorbed
Metabolism	none
Half life	6 to 9 hours
Excretion	unchanged in urine
Therapeutic considerations
Pregnancy cat.	?
Legal status
Routes	oral

Amiloride is a potassium-sparing diuretic, first approved for use in 1967 (then known as MK 870), used in the management of hypertension and congestive heart failure.

Contents 1 Structure 2 Mode of action 3 See also 4 References

[edit] Structure

Amiloride is a guanidinium group containing pyrazine derivative.

[edit] Mode of action

Amiloride works by directly blocking the epithelial sodium channel (ENaC) thereby inhibiting sodium reabsorption in the distal convoluted tubules and collecting ducts in the kidneys (this mechanism is the same for triamterene). This promotes the loss of sodium and water from the body, but without depleting potassium. The drug is often used in conjunction with thiazide (e.g. co-amilozide) or loop diuretics (e.g. co-amilofruse). Due to its potassium-sparing capacities, hyperkalemia (high blood potassium levels) are occasionally observed in patients taking amiloride. The risk is high in concurrent use of ACE inhibitors or spironolactone. Patients are also advised not to use potassium-containing salt replacements.^[1] Amiloride also carries the risk of developing an acidosis.

A fraction of the effects of amiloride is inhibition of cyclic GMP-gated cation channels in the inner medullary collecting duct.^[2]

[edit] See also

• Benzamil

[edit] References

1. ^ LoSalt Advisory Statement (PDF)
2. ^ Walter F., PhD. Boron. Medical Physiology: A Cellular And Molecular Approaoch. Elsevier/Saunders. ISBN 1-4160-2328-3.  page 875

v • d • e Antihypertensives (C02) and diuretics (C03) Sympatholytic agents (including alpha) centrally acting/antiadrenergics: Clonidine • Guanfacine • Methyldopa • Moxonidine • Rilmenidine • adrenergic uptake inhibitor (Rescinnamine, Reserpine) ganglion-blocking/nicotinic antagonist (Mecamylamine, Trimethaphan) peripherally acting/antiadrenergics (Prazosin, Guanethidine, Indoramin, Doxazosin) Vasodilators Diazoxide • Hydralazine • Minoxidil • Nitroprusside • Phentolamine Other antihypertensives serotonin antagonist (Ketanserin) • endothelin receptor antagonist (Bosentan, Ambrisentan, Sitaxsentan) Low ceiling diuretics Thiazide (Bendroflumethiazide, Chlorothiazide, Hydrochlorothiazide) • Chlortalidone • Indapamide • Quinethazone • Mersalyl • Metolazone • Theobromine • Cicletanine High ceiling diuretics Loop diuretic (Bumetanide, Furosemide, Torasemide) Potassium-sparing diuretics ESC blockers (Amiloride, Triamterene) • aldosterone antagonists (Spironolactone, Eplerenone, Potassium canrenoate, Canrenone)