Hydrochlorothiazide: Possible potentiation of orthostatic hypotension w/ alcohol, barbiturates or narcotics. Oral antidiabetic agents & insulin. Additive effect or potentiation w/ other antihypertensives. Decreased absorption w/ cholestyramine & colestipol resins. Intensified electrolyte depletion particularly hypokalemia w/ corticosteroids, ACTH. Possible decreased response to pressor amines (eg, norepinephrine). Potential increased responsiveness to nondepolarizing skeletal muscle relaxants eg, tubocurarine. Lithium. Reduced effect by NSAIDs.