Increased digoxin peak plasma & trough conc. Increased risk of hyperkalaemia w/ K-containing salt substitutes, K-sparing diuretics, K supplements, ACE inhibitors, NSAIDs, selective COX-2 inhibitors, heparin, immunosuppressives, trimethoprim. Reversible increased serum lithium conc & toxicity. Reduced antihypertensive effect w/ NSAIDs ie, ASA, COX-2 inhibitors, non-selective NSAIDs. Vol depletion & risk of hypotension w/ high-dose diuretics eg, furosemide or hydrochlorothiazide. Increased BP-lowering effect w/ other antihypertensives. Potentiated hypotensive effects w/ baclofen, amifostine. Aggravated orthostatic hypotension w/ alcohol, barbiturates, narcotics or antidepressants. Reduced antihypertensive effect w/ systemic corticosteroids.