Potassium-sparing diuretics adverse effects

Potassium-sparing by diuretic agents, particularly spironolactone, enhances the effectiveness of other diuretics because the secondary hyperaldosteronism is blocked. This class of diuretics decreases magnesium excretion, eg, amiloride can decrease renal excretion of potassium up to 80%. The most important and dangerous adverse effect of all potassium-sparing diuretics is hyperkalemia, which can be potentially fatal the incidence is about 0.5% (50). Therefore, blood potassium concentrations should be monitored carehiUy. 

POTASSIUM-SPARING DIURETICS CICLOSPORIN t risk of hyperkalaemia Additive effect >- For signs and symptoms of hyperkalaemia, see Clinical Features of Some Adverse Drug Interactions, Hyperkalaemia... 

POTASSIUM-SPARING DIURETICS ANTIVIRALS-PROTEASE INHIBITORS Possibly t adverse effects of eplerenone with nelfinavir, ritonavir (with or without lopinavir) and saquinavir Inhibition of CYP3A4-mediated metabolism of eplerenone Avoid concomitant use... 

Amiloride is a potassium-sparing diuretic that acts in the distal convoluted tubule independently of the action of aldosterone, inhibiting sodium channels. It is a relatively safe drug with few reported adverse effects. 

Vidt DG. Mechanism of action, pharmacokinetics, adverse effects, and therapeutic uses of amiloride hydrochloride, a new potassium-sparing diuretic. Pharmacotherapy 1981 l(3) 179-87. 

Epierenone is a potassium-sparing diuretic. It is similar to spironolactone as an aldosterone antagonist, but has less affinity for androgen and progesterone receptors and may therefore have fewer adverse effects (1). 

Spironolactone is a competitive antagonist at aldosterone receptors. It acts through its active metabohte, canrenone. Canrenone itself has also been used as a potassium-sparing diuretic for intravenous use and its potassium salt has been used orally, in the hope of avoiding the hormonal adverse effects of spironolactone. 

The adverse effects of ACE inhibitors are excessive hypotension associated with volume or salt depletion. All ACE inhibitors commonly cause a dry cough and rarely may cause angioedema. Renal failure can occur in patients with bilateral renal artery stenosis. Hyperkalemia may occur in patients with renal insufficiency, diabetics with even mild renal impairment, and patients taking potassium supplements or potassium-sparing diuretics. ACE inhibitors are fetotoxic and are not recommended for use during pregnancy. 

Not established. Thiazide diuretics combined with potassium-sparing diuretics are said to be particularly liable to cause hyponatraemia. Trimethoprim can also cause hyperkalaemia , by blocking amiloride-sensitive sodium channels in the collecting duct (this produces a similar effect to that of a potassium-sparing diuretic). It seems likely that these adverse effects can be additive with the effects of other drugs. 

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