Pharmacokinetics of Efavirenz 600mg in Combination with Rifampicin in Chinese HIV/TB Co-Infection Patients

Abstract

Background

Rifampicin is a known inducer of the cytochrome P450 (CYP2B6) enzyme, which can lead to a decrease in the concentration of efavirenz. Therefore, we conducted a study to evaluate the effect of daily rifampicin intake on efavirenz 600mg pharmacokinetics and HIV-1 virological suppression.

Methods

Patients receiving antiretroviral therapy containing efavirenz (600mg daily), and we collected efavirenz concentration at four visit points: ART day 14 (PK1), ART day 42 (PK2), ART day 140 (PK3), and ART day 336 (PK4), and performed pharmacokinetics analysis.

Results

From February 2017 to November 2020, 29 HIV/TB co-infection patients were included. Ninety percent of patients had a concentration of ≥1000ng/mL of efavirenz during the study. All patients had efavirenz C_max ≥1000ng/mL, 86% patients showed good virology response.

Conclusion

Our study shows that the use of rifampicin in HIV/TB co-infection patients does not affect efavirenz drug concentrations, that virological suppression is good and that no efavirenz dose adjustment is required.

Keywords:

• HIV/TB
• rifampicin
• efavirenz
• pharmacokinetics

Ethical Approval

The study was approved by the Committee of Ethics at Beijing Ditan Hospital, Capital Medical University, Beijing, China (Registration No.201704002).

Acknowledgments

We thank patients for their participation and dedication to HIV/TB research. We thank the staff of Beijing Ditan hospital for their support.

Author Contributions

All authors made a significant contribution to the work reported, whether that is in the conception, study design, execution, acquisition of data, analysis and interpretation, or in all these areas; took part in drafting, revising or critically reviewing the article; gave final approval of the version to be published; have agreed on the journal to which the article has been submitted; and agree to be accountable for all aspects of the work.

Disclosure

The authors have no competing interests to declare.

Additional information

Funding

This work was supported by the Clinical characteristic applied research and achievement promotion in the capital, Name: Study on the effect of rifampicin on the blood concentration of efavirenz in HIV/TB patients (Z171100001017053).