Increased risk of hypotension, hyperkalemia & renal function changes w/ angiotensin-receptor blockers, ACE inhibitors or aliskerin. Reversible increased serum lithium conc & toxicity. Attenuated antihypertensive effect w/ NSAIDs ie, selective COX-2 inhibitors, acetylsalicylic acid, non-selective NSAIDs. Enhanced antihypertensive effects w/ other BP-lowering medicines. Increased serum K w/ K-sparing diuretics, K supplements or K-containing salt substitutes, heparin Na.