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.

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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

[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

[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