Alteration of the Pharmacokinetics of Theophylline by Paullinia cupana Kunth in Rats

Aims: Paullinia cupana Kunth has been popularly used to prepare different beverages by the Amazonian inhabitants for a long time ago mainly due to its stimulant properties. Although the utilization of this herbal drug has been increasing lately, little is known regarding the possibility of drug interactions. Therefore, this research tried to investigate the effects of the aqueous extract of P. cupana on the pharmacokinetics of theophylline (TPH), a CYP1A marker in rats.

Methodology: The extract was prepared according to the popular recipe and subjects received different once daily doses of extract (vehicle, 82.1 mg/Kg and 821 mg/Kg) by oral gavage during two weeks. Non-compartimental analysis was carried out to obtain the pharmacokinetic parameters.

Results: Animals treated with P. cupana (AUC: 1,197.2 ± 284.4 and 346.6 ± 37.0 µg.h/mL for 82.1 and 821 mg/Kg, respectively) had lower exposition to TPH than controls (3,539.48 ± 278.4 µg.h/mL). On the other hand, drug clearance was higher in treated subjects (2.44 ± 0.4 and 7.27 ± 0.7 L/h/kg for 82.1 and 821 mg/Kg, respectively) than controls (0.71 ± 0.0 L/h/kg).

Conclusion: Therefore, the multiple oral administration of an aqueous extract of P. cupana caused a significant effect on the pharmacokinetics of TPH in rats.