Date of report 25 Feb 2020
Reported case interaction between
Efavirenz and Carvedilol
Efavirenz and Carvedilol
Drugs suspected to be involved in the DDI
Complete list of drugs taken by the patient
Carvedilol, enalapril
Clinical case description
41-year-old HIV positive patient, known for HIV infection since 2017. Undetectable on EFC/FTC/TDF (first and only regimen). Admitted to cardiology service for service due to diagnosis of hyperphophic cardiomyopathy. Carvedilol and enalapril were prescribed and HIV consultation was requested to evaluate the need for treatment modifications of the ARV regimen. Carvedilol undergoes glucuronidation and additional metabolism via CYP2D6 and CYPs 2C9 and 1A2. Efavirenz could potentially increase carvedilol concentrations via CYP2C9 inhibition or decrease carvedilol concentrations via induction of glucuronidation (UGT1A1), being unknown the net final effect. No interactions were expected with enalapril. EFC/FTC/TDF was decided to be maintained with no side effects observed. The ART regimen was changed some months later due to other reasons (avoid EFV effect on cholesterol).
Clinical Outcome
Editorial Comment
The interaction between efavirenz and carvedilol is one that has been difficult to predict due to the potential for both induction (UGT1A1) and inhibition (CYP2C9). This case report is helpful and lends some support to the recommendation of 'no a priori dosage adjustment' that is currently in the DDI resource www.hiv-druginteractions.org.
University of Liverpool Recommendation
Potential interaction likely to be of weak intensity. Additional action/monitoring or dosage adjustment is unlikely to be required