Potassium-sparing diuretics interactions

Finnegan TP, Spence JD, Cape R. Potassium-sparing diuretics interaction with dioxin in elderly men J Am GeriatrSoc (1984) 32,129-31. 

No significant interactions have been reported when tiie expectorants are used as directed. The exception is iodine products. Lithium and other antithyroid drug may potentiate the hypotliyroid effects of these drug if used concurrently with iodine products. When potassium-containing medications and potassium-sparing diuretics are administered with iodine products, the patient may experience hypokalemia, cardiac arrhythmias, or cardiac arrest. Thyroid function tests may also be altered by iodine... 

The hypotensive effects of most antihypertensive dru are increased when administered with diuretics and other antihypertensives. Many dnigp can interact with the antihypertensive drugs and decrease their effectiveness (eg, antidepressants, monoamine oxidase inhibitors, antihistamines, and sympathomimetic bronchodilators). When the ACE inhibitors are administered with the NSAIDs, their antihypertensive effect may be decreased. Absorption of the ACE inhibitors may be decreased when administered with the antacids. Administration of potassium-sparing diuretics or potassium supplements concurrently with the ACE inhibitors may cause hyperkalemia. When the angiotensin II receptor agonists are administered with... 

Drugs that may interact include ACE inhibitors, potassium-sparing diuretics, digitalis, and potassium-containing salt substitutes. 

Other drugs that may interact with cardiac glycosides include the following Albuterol, amphotericin B, beta-blockers, calcium, disopyramide, loop diuretics, nondepolarizing muscle relaxants, potassium-sparing diuretics, succinylcholine, sympathomimetics, thiazide diuretics, thioamines, and thyroid hormones. 

Important drug interactions include those with potassium supplements or potassium-sparing diuretics, which can result in hyperkalemia. Nonsteroidal anti-inflammatory drugs may impair the hypotensive effects of ACE inhibitors by blocking bradykinin-mediated vasodilation, which is at least in part, prostaglandin mediated. 

Cyclosporine has significant nephrotoxicity, and its toxicity can be increased by drug interactions with diltiazem, potassium-sparing diuretics, and other drugs inhibiting CYP3A. Serum creatinine should be closely monitored. Other toxicities include hypertension, hyperkalemia, hepatotoxicity, gingival hyperplasia, and hirsutism. 

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... 

Interactions. Hyperkalaemia can result from use with potassium-sparing diuretics. Renal clearance of lithium is reduced and toxic concentrations of plasma lithium may follow. Severe hypotension can occur with diuretics (above), and with chlorpro-mazine, and possibly other phenothiazines. 

Pentamidine is structurally similar to amiloride and can cause severe hyperkalemia if co-prescribed with potassium-sparing diuretics (10). This is a particularly important interaction in patients with AIDS. 

The interaction between potassium-sparing diuretics and NSAIDs is well documented (SED-14, 674). The major complications are deterioration of renal function and hjrper-kalemia. The risk associated with the non-selective COX-2 inhibitors is unknown. However, three patients had hyperkalemia (8.5, 5.4, and 5.1 mmol/1) after developing acute renal insufficiency while taking these drugs (8). 

Lithium is also known to interact in a variety of ways with different classes of diuretic drugs. Thiazide diuretics increase serum lithium concentration by increasing reabsorption of lithium, along with that of sodium, in the proximal tubule. With potassium-sparing diuretics, conflicting results have been reported. Increased serum lithium concentrations may be seen after amiloride. However, the loop diuretic furosemide safely can be combined with lithium with no reduction in renal lithium clearance or consequent increase in serum lithium concentration (191, 192). Other diuretics, for example, carbonic anhydrase inhibitor and xanthine derivatives, decrease serum... 

Clinically important, potentially hazardous interactions with amiodarone, beta-blockers, caspofungin, cyclosporine, dairy products, danazol, erythromycin, etoricoxib, grapefruit juice, hemophilus B vaccine, HMG-CoA reductase inhibitors, ibuprofen, immunosuppressants, ketoconazole, lopinavir, lovastatin, mycophenolate, peanuts, potassium, potassium-sparing diuretics, rifabutin, rifampin, rifapentine, simvastatin, St John s wort, telithromycin, vaccines... 

Clinically important, potentially hazardous interactions with allopurinol, amiloride, cimetidine, corticosteroids, cyclosporine, insulin, lithium, potassium sparing diuretics, potassium supplements, procainamide, spironolactone, triamterene... 

One of the best-known lithium interactions is the clinically relevant reduction of renal lithium clearance by combined administration of the drug with diuretics. Special caution is advised when long-term thiazides are combined with lithium. The potassium-sparing diuretics such as spironolactone can also increase plasma... 

The loop diuretics, bumetanide, furosemide and torasemide, the potassium-sparing diuretic spironolactone, and the thiazides chlortalidone and chlorothiazide, have all been shown either not to interact or to cause only a small reduction in the effects of the coumarin anticoagulants of minimal or no clinical importance. The lack of reports of clinically relevant interactions su ests that, in general, diuretics do not interact with anticoagulants. The possible exception is etacrynic acid, which on rare occasions has caused a marked increase in the effects of warfarin. 

Sudden deaths, probably from cardiac arrhythmias, were markedly Increased In patients taking potassium-depleting diuretics and high doses of ketanserin. No interaction occurred with low doses of ketanserin in those with normal potassium levels. Potassium-sparing diuretics do not interact in this way. 

The use of potassium-depleting diuretics (see Table 26.1 (p.944)) with ketanserin 40 mg three times daily should be avoided. Lower doses of ketanserin (20 mg twice daily) have less effect on the QT interval, and can probably be used cautiously with potassium-depleting diuretics, as long as serum potassium levels are maintained. Potassium-sparing diuretics do not interact. 

Although minor interactions occasionally occur between potassium-sparing diuretics and the H2-receptor antagonists, none of these have been shown to be of clinical significance. The combinations that have been studied are amiloride or triamterene with ci-metidine, and triamterene with ranitidine. 

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