Abstract
Black tea extract (leaves and buds of the plant Camellia sinensis) consumption is generally thought to be safe and does not cause medical problem. Carbamazepine (CBZ) is used for the treatment of epileptic patients and it is extensively metabolized by liver enzymes. However, tea components (caffeine, theophylline, and theobromine) induce liver enzymes and may induce the metabolism of CBZ. Furthermore, physician should be aware regarding this interaction. The aim of this study is to predict the possibility of interactions of tea components with the disposition of carbamazepine (CBZ) in epileptic patients. The pharmacokinetic parameters CBZ steady state serum concentrations (C-SS) and total CBZ clearances (Cl-T) were estimated. This study was conducted on thirty one epileptic inpatients, they were allocated into four groups, patients in group (I) and (II) were already on chronic CBZ treatment, while patients in group (III) and (IV) initiate CBZ therapy during the study. The (C-SS) for patients in group (I and III), who were tea drinker, are significantly increased after 7 days of stopping tea consumption, and (Cl-T) are significantly decreased. The (C-SS) for patients in groups (II and IV), who drunk no tea for 7 days before sampling, are significantly decreased after 7 days of drinking tea and the (Cl-T) and so are significantly increased. The total volume of tea extract given to the patients in each group is about (600 mL/day). According to these results epileptic patients, who are tea drinker, treated with CBZ, require therapeutic drug monitoring.