Increased serum conc & toxicity of lithium. Increased risk of hypotension, hyperkalemia & changes in real function including acute renal failure w/ angiotensin receptor antagonist, ACE inhibitors or aliskiren. May increase risk of worsening renal function w/ NSAIDs. Attenuated antihypertensive effect w/ NSAIDs including COX2 inhibitors. Reduced systemic exposure & peak plasma conc w/ colesevelam HCl.