Synonyms: [4S-(4alpha,4aalpha,5aalpha,6beta,12aalpha)]-4-(Dimethylamino)-1,4,4a,5,5a,6,11,12a-octahydro-3,6,10,12,12a-pentahydroxy-6-methyl-1,11-dioxo-2-naphthacenecarboxamide hydrochloride; Tetracycline hcl; (2Z,4S,4aS,5aS,6S,12aS)-2-[amino(hydroxy)methylidene]-4-(dimethylamino)-6,10,11,12a-tetrahydroxy-6-methyl-4a,5a,6,12a-tetrahydrotetracene-1,3,12(2H,4H,5H)-trione hydrochloride; (2E,6S,12aS)-2-[amino(hydroxy)methylidene]-4-(dimethylamino)-6,10,11,12a-tetrahydroxy-6-methyl-4a,5a,6,12a-tetrahydrotetracene-1,3,12(2H,4H,5H)-trione hydrochloride; 4-(dimethylamino)-3,6,10,12,12a-pentahydroxy-6-methyl-1,11-dioxo-1,4,4a,5,5a,6,11,12a-octahydrotetracene-2-carboxamide hydrochloride (1:1)