May raise plasma conc of lithium or digoxin. Decreased antihypertensive effect of diuretics or antihypertensive agents (eg, β-blockers, ACE inhibitors). Increased risk of nephrotoxicity w/ diuretics & ACE inhibitors; ciclosporin; tacrolimus. Increased serum K levels w/ K-sparing diuretics, ciclosporin, tacrolimus or trimethoprim. Increased risk of bleeding w/ anticoagulants & anti-platelet agents. Increased risk of GI bleeding or ulceration w/ other systemic NSAIDs or corticosteroids; SSRIs. Isolated reports of hypoglycemic & hyperglycemic effects necessitating changes in the dosage of antidiabetic agents during treatment w/ diclofenac. Increased blood conc & toxicity of MTX. Convulsions may occur w/ quinolones. Increased exposure to phenytoin. Delayed or decreased absorption w/ colestipol & cholestyramine. Concomitant use of cardiac glycosides may exacerbate cardiac failure, reduce GFR & increase plasma glycoside levels. Reduced effect of mifepristone. Increased peak plasma conc & exposure w/ potent CYP2C9 inhibitors (eg, voriconazole).