Losartan K: Rifampicin, fluconazole, K-sparing diuretics, K supplements or salts. Hydrochlorothiazide: Alcohol, barbiturates, narcotics, oral antidiabetics, insulin, other antihypertensives, cholestyramine, colestipol resins, corticosteroids, ACTH, pressor amines eg, adrenaline.