A Study of Effect of Catha Edulis on Bioavailability of Sildenafil by Using Everted Sac Method

Abstract

Background: Catha Edulis is a widespread plant in some countries such as Yemen. This plant is taken by most populations in Yemen and other countries and can affect the bioavailability of many drugs such as sildenafil.

Objectives: The study aimed to knowledge and evaluation of the effect of the presence of khat in the GIT on the bioavailability and efficacy of sildenafil.

Methods: The present study was carried out in ex-vivo by using everted gut sac method. In comparative studies for absorption of standard sildenafil alone and stand. sildenafil in presence of more than one type of khat (Ansi and Hamdani) and confirm this study by comparative study for sildenafil (Viagra) alone and in presence of the more effective type of khat (Ansi).

Results: In the proposed studies, by using the calibration curve equation to calculate Conc. %,  the means of the difference in  Conc.% of the stand. sildenafil alone and stand. sildenafil in presence of khat Ansi and stand. sildenafil in presence of khat Hamdani were 14.14 ± 2.922 and 8.316 ± 0.868 respectively, and the mean difference in  Conc.% of sildenafil (Viagra) alone and sildenafil (Viagra) in presence of khat ANSI was 19.986 ± 3.981.

Conclusions: Based on the results obtained from the study, the sildenafil bioavailability was significantly reduced in the presence of khat. The rate of reduction was affected by the type of khat, as al-ANSI khat was more effective than al-Hamdani khat in the reduction of bioavailability of sildenafil.