DRUGS AND THEIR ACTIVE METABOLITES SR.NO. DRUG ACTIVE METABOLITE 1 Allopurinol Oxipurinol (Alloxanthine) 2 Amytryptylline Nortryptalline 3 Amphetamine P-Methoxy Amphetamine 4 Carmapazepine Carmapazemine-10,11-Eporide 5 Carbimazole Thiamazole 6 Cephaloglycine Desacetyl Cephaloglycine 7 Chloral Hydrate Trichloroethanol 8 Chlordiazepoxide 7-hydroxy Chloropromazine 9 Chlorpromazine 7-hydroxy Chloropromazine 10 Chlorguanidine Cyclogunal 11 Clofibrate Free acid metabolite 12 Imipramine N-oxide metabolite 13 Codeine Morphine,Norcodeine 14 Diazepam Oxazepam.N-Me-Oxazepam 15 Fenfluramine Nor Fenfluramine 16 Guanethadine N-Oxide 17 Lignocaine N-Desmethyl metabolite 18 Morphine Nor morphine 19 Naloxane 6-􀀀-hydroxy Naloxane 20 Phenacetin Paracetamol 21 Prednisone Prednisolone 22 Premidone Phenobarbitone 23 Spironolactone Canrenone 24 Procainamide N-Acetyl metabolite 25 Propanolol N-deisopropyl met 26 Quinidine 3-Hydroxy quinone 27 Rifampicine Desacetylated metabolite