Increased hypotensive effects w/ diuretics & other antihypertensives. Higher frequency of adverse events eg, hypotension, hyperkalaemia & decreased renal function w/ aliskiren-containing drugs & ACE inhibitors. Increased serum K w/ K-sparing diuretics, K supplements, K-containing salt substitutes. Reversible increased serum lithium conc & toxicity. Attenuated antihypertensive effect w/ NSAIDs, selective COX-2 inhibitors, ASA & non-selective NSAIDs.