Increased hypotensive effects w/ other antihypertensives. Higher frequency of adverse reactions w/ ACE inhibitors, AIIAs or aliskiren. Vol depletion & risk of hypotension w/ high dose diuretics. Increased serum K w/ K-sparing diuretics, K supplements, salt substitutes containing K or products that may increase K level (eg, heparin). Reversible increase in serum lithium conc & toxicity of lithium. Increased risk of worsening of renal function, increase serum K & attenuation of antihypertensive effect w/ NSAIDs (ie, selective COX-2 inhibitors, acetylsalicylic acid >3 g/day & non-selective NSAIDs).