Date of report: 20 Jul 2020
Reported case interaction between
Etravirine and Apixaban
Etravirine and Apixaban

Drugs suspected to be involved in the DDI
Drug A
Etravirine
(Perpetrator)
Daily Dose
400
(mg)
Dose adjustment performed
No
Administration Route
Oral
Start date
Dec. 1, 2008
End date
Ongoing
Drug B
Apixaban
(Victim)
Daily Dose
10
(mg)
Dose adjustment performed
Yes
Administration Route
Oral
Start date
Feb. 2, 2019
End date
Unknown
Complete list of drugs taken by the patient
Antiretroviral treatment
Etravirine
Emtricitabine/Tenofovir-DF
Complete list of all comedications taken by the patient, included that involved in the DDI
apixaban
Clinical case description
Gender
Male
Age
50
eGFR (mL/min)
>60
Liver function impairment
No
Description
50 year man durably suppressed on Truvada and Etravirine (HIV seroconversion in 2003 with V106I RT mutation, intolerant of EFV (CNS disturbance), borderline eGFR 68mls/min.
2019 presented with pleuritic chest pain and breathlessness, CT confirmed extensive bilateral pulmonary emboli.
Since unprovoked pulmonary embolism, for lifelong anticoagulation, apixaban started at standard dosing 5mg bd for 1 week, then 2.5mg daily (prescriber unaware of potential DDI with etravirine). HIV team continued apixaban dosing at 5mg bd- heparin concentrations were therapeutic (1.37U/mL). However, dose subsequently dropped to recommended maintenance of 2.5mg daily- heparin concentrations were subtherapeutic at 0.59 U/mL. DDI considered likely, antiretrovirals changed to an integrase regimen.
Outcome
Loss of efficacy
Drug Interaction Probability Scale (DIPS)
Score
5 - Probable
Editorial Comment
Coadministration has not been studied. Apixaban is metabolized by CYP3A4 and to a lesser extent by CYP1A2, CYP2C8, CYP2C9 and CYP2C19. Etravirine could potentially decrease apixaban exposure resulting in diminished efficacy. In this situation, it may be recommended changing cART to unboosted integrase inhibitors, as in the present clinical case.