title: Enhanced biotransformation of theophylline in marihuana and tobacco smokers.
abstract: Single oral doses of theophylline were administered to 7 chronic marihuana smokers, to 7 chronic users of both marihuana and tobacco, and to 43 appropriate control subjects. Theophylline was cleared from the blood more rapidly in both marihuana and tobacco smokers with a mean increase in total clearance from 52 ml/kg/hr in nonsmokers to 74 ml/kg/hr in subjects who smoked either material alone. There was an additive increase in clearance to 93 ml/kg/hr in those who smoked both substances. Concern over enhanced metabolism of other drugs is probably warranted in tobacco and cannabis smokers.
mesh_terms: D000328:Adult; D000628:Aminophylline / Q000378:metabolism; D001711:Biotransformation; D002188:Cannabis; D005260:Female; D006801:Humans; D007700:Kinetics; D008297:Male; D008875:Middle Aged; D012463:Saliva / Q000032:analysis; D012907:Smoking / Q000378:metabolism*; D013806:Theophylline / Q000097:blood / Q000378:metabolism*; D013861:Thiocyanates / Q000097:blood
chemical_list: D013861:Thiocyanates; D000628:Aminophylline; D013806:Theophylline