Skip to content
Research Article Open access CC BY 3.0

The Effect of Green Tea on Sildenafil Pharmacokinetics in Egyptian Healthy Volunteers

Sahar K. Hegazy

Journal of Pharmaceutical Research International · pp. 289–300 · Published 25 Nov 2013

10.9734/BJPR/2014/6905

Abstract

Aim: To investigate the interaction of slidenafil and green tea in normal healthy male volunteers using probe drugs (midazolam, CYP3A4 activity). Study Design:  Ten healthy males were included in random crossover single dose study.  Each volunteer received one tablet of sildenafil 50 mg and one tablet of midazolam 7.5 mg concurrently either after drinking 250 ml of water or 250 ml of fresh extract of 2 gram of green tea. After one week washout period, each volunteer received the other intervention. Plasma samples were analyzed for sildenafil and midazolam using HPLC. Place and Duration of Study: The Laboratory of Pharmaceutical Research Center of Faculty of Pharmacy, Tanta University, Egypt, between June to July 2013. Methodology: Blood samples were obtained after the insertion of peripheral cannula into the forearm. Samples were obtained before sildenafil and midazolam intake (blank) and at 0.25, 0.5, 0.75, 1, 1.5, 2, 3, 5, 8, 10, and 12 hours after sildenafil and midazolam administration. The samples were collected in clean heparinized tubes. Plasma was obtained by centrifugation and was stored at –20° until assay. Plasma samples were analyzed for sildenafil and midazolam using HPLC. Results: Coadministration of green tea with sildenafil tea increased the extent but not the rate of sildenafil absorption. It resulted in higher plasma concentrations (AUC∞ increased from 484.2 ± 67.27 μg hr/L to 731.5 ± 111.01 μg hr/L (90% CI 1.50 (1.36-1.66) and the Cmax from 318.9 ± 46.8 μg /L to 414.9 μg/L ± 67.0 μg/L (90% CI 1.29 (1.15-1.43). The elimination rate constant of sildenafil was significantly decreased and the elimination half life was prolonged by about 36%. However, AUC∞ of midazolam increased by 16% and Cmax by 14%; suggesting a small reduction CYP 3A4 activity. Conclusion: Increased bioavailability of sildenafil after green tea intake may be caused by the effect of catechins which can alter spontaneous activity of small intestine or an effect on transporters. Patients who are taking green tea may need smaller doses of sildenafil, and those at higher risk of developing sildenafil adverse effects and are taking green tea should seek medical advice before taking their sildenafil therapy.

Sildenafil green tea pharmacokinetics bioavailability

References (28)

  1. 1 Green tea composition, consumption, and polyphenol chemistry [DOI]
  2. 2 Sildenafil: an orally active type 5 cyclic GMP-specific phosphodiesterase inhibitor for the treatment of penile erectile dysfunction.
  3. 3 Pharmacokinetics and safety of green tea polyphenols after multiple-dose administration of epigallocatechin gallate and polyphenon E in healthy individuals.
  4. 4 Pharmacokinetics and metabolism of sildenafil in mouse, rat, rabbit, dog and man [DOI]
  5. 5 Polymorphisms in Human Organic Anion-transporting Polypeptide 1A2 (OATP1A2) [DOI]
  6. 6 Pharmacokinetics of sildenafil after single oral doses in healthy male subjects: absolute bioavailability, food effects and dose proportionality [DOI]
  7. 7 Metabolism of Green Tea Catechins: An Overview [DOI]
  8. 8 Naringin is a Major and Selective Clinical Inhibitor of Organic Anion-Transporting Polypeptide 1A2 (OATP1A2) in Grapefruit Juice [DOI]
  9. 9 Appropriate Phenotyping Procedures for Drug Metabolizing Enzymes and Transporters in Humans and Their Simultaneous Use in the “Cocktail” Approach [DOI]
  10. 10 Interactions of Green Tea Catechins with Organic Anion-Transporting Polypeptides [DOI]
  11. 11 Inhibition by green tea catechins of metabolic activation of procarcinogens by human cytochrome P450 [DOI]
  12. 12 Effects of Repeated Green Tea Catechin Administration on Human Cytochrome P450 Activity [DOI]
  13. 13 Comparative human pharmacokinetics and metabolism of single‐dose oral and intravenous sildenafil [DOI]
  14. 14 GREEN TEA (CAMELLIA SINENSIS) EXTRACT DOES NOT ALTER CYTOCHROME P450 3A4 OR 2D6 ACTIVITY IN HEALTHY VOLUNTEERS [DOI]
  15. 15 Effects of Green Tea Catechins on Cytochrome P450 2B6, 2C8, 2C19, 2D6 and 3A Activities in Human Liver and Intestinal Microsomes [DOI]
  16. 16 Effects of Continuous Ingestion of Green Tea or Grape Seed Extracts on the Pharmacokinetics of Midazolam [DOI]
  17. 17 Green tea extract can potentiate acetaminophen-induced hepatotoxicity in mice [DOI]
  18. 18 The effects of green tea polyphenols on drug metabolism [DOI]
  19. 19 Plasma protein binding of polyphenols from maritime pine bark extract (USP) [DOI]
  20. 20 Effects of grapefruit juice on the pharmacokinetics of sildenafil [DOI]
  21. 21 Effect of Grapefruit Juice on the Pharmacokinetics of Microemulsion Cyclosporine and its Metabolite in Healthy Volunteers: Does the Formulation Difference Matter? [DOI]
  22. 22 Determination of Sildenafil Citrate in Plasma by High-Performance Liquid Chromatography and a Case for the Potential Interaction of Grapefruit Juice With Sildenafil Citrate [DOI]
  23. 23 Transport by OATP1B1 and OATP1B3 Enhances the Cytotoxicity of Epigallocatechin 3-O-Gallate and Several Quercetin Derivatives [DOI]
  24. 24 The Effect of Green Tea on Simvastatin Tolerability [DOI]
  25. 25 The effects of pummelo juice on pharmacokinetics of sildenafil in healthy adult male Jordanian volunteers [DOI]
  26. 26 Increased Plasma Levels of Tacrolimus After Ingestion of Green Tea [DOI]
  27. 27 The Effect of Epigallocatechin Gallate on Intestinal Motility in Mice [DOI]
  28. 28 (-)-Epigallocatechin Gallate Inhibits the Pacemaker Activity of Interstitial Cells of Cajal of Mouse Small Intestine [DOI]

Cited by 27

Investigation of the regulatory effects of tea polyphenols on CYP450s in HepG2 cells

Dan Zuo, Hong Ren, Zhaoxu Ren · Frontiers in Nutrition · 2025

Green Tea Catechins as Perpetrators of Drug Pharmacokinetic Interactions

Nicki M Kyriacou, Annette S. Gross, Andrew J. McLachlan · Clinical pharmacology and therapy · 2025

Green tea: Current trends and prospects in nutraceutical and pharmaceutical aspects

A. Sarma, Ratnali Bania, M. K. Das · Journal of Herbal Medicine · 2023

Bioactive compounds in tea: Effect of imbalanced intake on digestive enzymes activity, cytochrome inhibition and drug interaction

Supaluck Kraithong, Narudol Teerapattarakan, B. Balasubramanian · South African Journal of Botany · 2022

Pharmacokinetic profile of sildenafil citrate in healthy Middle Eastern Males: Comparison with other ethnicities

Abdulrahman M Alwhaibi, Sary Alsanea, Ziyad Alrabiah · Saudi Pharmaceutical Journal · 2021

INTERACTION OF SILDENAFIL WITH HERBAL SUPPLEMENTS: A REVIEW

I. Abushammala · Bulletin of Pharmaceutical Sciences. Assiut · 2021

[Pharmacokinetic interactions of fruit juices and herbal preparations].

M. Cortés, R. Díaz, Samuel Verdugo · Revista médica de Chile (Impresa) · 2021

Showing 16 of 27 known citations — external sources report more than can currently be individually listed.

Article metrics

Real usage data collected on this platform.

6

Page views

0

PDF downloads

1

Outbound clicks

27

Citations

Views over time

Views by country

Approximate, from request IP at view time — not citizenship or institution. Countries with fewer than 5 views are grouped as "Other".

Traffic sources

Referring site, by host.

Views and downloads exclude known bots/crawlers. Citations combines this platform's own DOI-resolved index with each external source's own reported total — see Cited by above for individually listed citing works. Last refreshed 0 seconds ago.