Lithium (increased toxicity), NSAIDs (reduced antihypertensive/diuretic effect, kidney risk), other antihypertensives (additive BP lowering), corticosteroids/amphotericin B (increased hypokalemia), digoxin (arrhythmia risk with low potassium), antidiabetic medicines/insulin (may alter glucose control), cholestyramine/colestipol (reduced absorption), alcohol (increased dizziness)