_____________________________________________________________________________________________________ *Corresponding author: E-mail: imagalhaes@ufam.edu.br; European Journal of Medicinal Plants 32(9): 12-18, 2021; Article no.EJMP.73622 ISSN: 2231-0894, NLM ID: 101583475 Alteration of the Pharmacokinetics of Theophylline by Paullinia cupana Kunth in Rats Nayana Yared Batista 1 , Ádley Antonini Neves de Lima 2 , José Wilson do Nascimento Corrêa 3 , Tatiane Pereira de Souza 1 and Igor Rafael dos Santos Magalhães 1* 1 Faculdade de Ciências Farmacêuticas, Universidade Federal do Amazonas, Manaus, Amazonas, Brazil. 2 Departamento de Farmácia, Universidade Federal do Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil. 3 Instituto de Ciências Biológicas, Universidade Federal do Amazonas, Manaus, Amazonas, Brazil. Authors’ contributions This work was carried out in collaboration among all authors. All authors read and approved the final manuscript. Article Information DOI: 10.9734/EJMP/2021/v32i930414 Editor(s): (1) Dr. Daniela Rigano, University Federico II of Naples, Italy. (2) Prof. Marcello Iriti, University of Milan, Italy. Reviewers: (1) Zhengshuang Xu, Peking University, China. (2) Shruti Chandra, India. Complete Peer review History: https://www.sdiarticle4.com/review-history/73622 Received 06 July 2021 Accepted 16 September 2021 Published 23 September 2021 ABSTRACT 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 Original Research Article