Renese® is designated generically as polythiazide, and chemically as 2H-1,2,4-Benzothiadiazine-7-sulfonamide, 6-chloro-3,4-dihydro-2-methyl-3-[[(2,2,2-trifluoroethyl)thio]methyl]-, 1,1-dioxide. It is a white crystalline substance, insoluble in water but readily soluble in alkaline solution.