Possible potentiation of orthostatic hypotension w/ alcohol, barbiturates or narcotics. Oral antidiabetic agents & insulin. Additive effect or potentiation w/ other antihypertensives. Reduced absorption w/ cholestyramine & colestipol resins. Intensified electrolyte depletion particularly hypokalemia w/ corticosteroids, ACTH. Possible decreased response to pressor amines (eg, norepinephrine). Possible increased responsiveness to nondepolarizing skeletal muscle relaxants eg, tubocurarine. Risk of lithium toxicity. Reduced diuretic, natriuretic & antihypertensive effect w/ NSAIDs. Risk of symptomatic hyponatremia w/ carbamazepine.