Increased serum K w/ K-sparing diuretic (eg, spirinolactone, triamterene), K supplement (eg, KCl). Increased risk of hypotension, hyperkalaemia & decreased renal function w/ ACE inhibitors, angiotensin II receptor blockers or aliskiren. Increased risk of orthostatic hypotension w/ barbituric acid derivatives, opium alkaloid narcotic or alcohol. Weakened action of pressor amine (eg, noradrenaline, adrenaline). Amplified neuromuscular blocking effects of tubocurarine & substances w/ similar effects (eg, tubocurarine Cl HCl hydrate, pancuronium Br). Amplified antihypertensive effects w/ β-blockers, nitroglycerin, other drugs w/ antihypertensive efects. Amplified effect of digitalis agent (eg, digoxin, digitoxin). Amplified metabolic alkalosis & hypokalaemia w/ Na lactate. Increased conc of lithium leading to lithium toxicity. Increased risk of hypokalemia w/ adrenal corticosteroid. Increased risk of decline of serum K w/ glycyrrhizinate drugs. Severely weakened action of diabetes drugs (eg, SU drugs, insulin). Weakened action of thiazide w/ cholestyramine. Weakened antihypertensive effect w/ NSAIDs (eg, indomethacin). Antagonized uric acid elimination action of sulfinpyrazone.