Does Rifampin Interact with Efavirenz Lamivudine And Tenofovir Disoproxil Fumarate?
Rifampin and Efavirenz Lamivudine And Tenofovir Disoproxil Fumarate have a moderate drug interaction according to U.S. FDA drug labeling data. Induction of CYP3A activity by rifampin may increase clearance of efavirenz resulting in lowered plasma concentrations. The mechanism involves cyp3a induction. Patients taking both medications should consult their healthcare provider before starting, stopping, or changing the dosage of either drug. This information is based on official FDA drug labeling sourced from OpenFDA and the NIH National Library of Medicine.
- Severity
- Moderate
- Rifampin Class
- Rifamycin Antibacterial
- Efavirenz Lamivudine And Tenofovir Disoproxil Fumarate Class
- Human Immunodeficiency Virus 1 Non-Nucleoside Analog Reverse Transcriptase Inhibitor
- Management
- Monitor for effects
- Data Source
- U.S. FDA via OpenFDA
How This Interaction Works
The interaction between Rifampin and Efavirenz Lamivudine And Tenofovir Disoproxil Fumarate occurs because cyp3a induction. Clinically, this means induction of cyp3a activity by rifampin may increase clearance of efavirenz resulting in lowered plasma concentrations. This is classified as a moderate interaction. While it may not require stopping either medication, your healthcare provider should be aware you are taking both so they can monitor for potential effects and adjust treatment if necessary.
What To Tell Your Doctor or Pharmacist
If you are taking Rifampin and your doctor is considering prescribing Efavirenz Lamivudine And Tenofovir Disoproxil Fumarate (or vice versa), make sure to:
- Inform your doctor and pharmacist of all current medications, including over-the-counter drugs and supplements
- Ask whether the benefits of combining these medications outweigh the risks for your specific situation
- Ask what symptoms to watch for that would indicate the interaction is causing problems
- Ask whether any dosage adjustments are needed
- Never stop or change either medication without first consulting your healthcare provider