Date of report 17 May 2024
Reported case interaction between
Efavirenz and Sofosbuvir + Velpatasvir
Efavirenz and Sofosbuvir + Velpatasvir
Drugs suspected to be involved in the DDI
Complete list of drugs taken by the patient
Sofosbuvir/velpatasvir
Clinical case description
A 48-year-old man was diagnosed with HIV infection in 2010, during a hospitalization for C. neoformans meningitis, CMV retinitis, and Kaposi sarcoma. Since his diagnosis, he has been undergoing treatment with efavirenz and lamivudine/abacavir and has shown virological suppression.
In December 2021, he was diagnosed with acute hepatitis C (HCV) and was subsequently prescribed treatment with sofosbuvir/velpatasvir. Unfortunately, both treatments were prescribed without consideration of potential drug interactions.
The patient completed a 12-week course of HCV treatment. However, it was later discovered that there had been a drug-drug interaction contraindicating the co-administration of both treatments. It is worth noting that the coadministration of velpatasvir/sofosbuvir with efavirenz-containing regimens is not recommended due to decreased concentrations of velpatasvir. Despite this, the patient achieved a sustained virological response for HCV, and a follow-up HCV viral load remained undetectable at week 24 post-treatment.
Clinical Outcome
Editorial Comment
Administration of sofosbuvir and velpatasvir with efavirenz/emtricitabine/ tenofovir disoproxil fumarate resulted in approximate 50% lower velpatasvir exposure, attributable to induction of CYP3A and P-gp. Based on this result, sofosbuvir/velpatasvir is not recommended for use with efavirenz-containing ARV regimens.
There are small case series of patients who have been treated with antiepileptic drugs with strong inducing properties during HCV DAA therapy (including with sofosbuvir/velpatasvir) and who achieved a sustained virologic response. Although every effort to prevent concomitant use of sofosbuvir/velpatasvir and inducers should be made, these cases, including the one presented here, suggest that HCV cure may still be achieved in patients where coadministration with an inducer cannot be avoided.
University of Liverpool Recommendation
These drugs should not be coadministered