Date of report: 22 Jun 2020
Reported case interaction between
Cobicistat and Aripiprazole
Cobicistat and Aripiprazole
Drugs suspected to be involved in the DDI
Drug A
Cobicistat
(Perpetrator)
Daily Dose
150
(mg)
Dose adjustment performed
No
Administration Route
Oral
Start date
Nov. 1, 2018
End date
Ongoing
Drug B
Aripiprazole
(Victim)
Daily Dose
5
(mg)
Dose adjustment performed
Yes
Administration Route
Oral
Start date
June 1, 2017
End date
Feb. 1, 2019
Complete list of drugs taken by the patient
Antiretroviral treatment
Darunavir/Cobicistat/Emtricitabine/Tenofovir-AF
Complete list of all comedications taken by the patient, included that involved in the DDI
No other drugs
Clinical case description
Gender
Male
Age
21
eGFR (mL/min)
>60
Liver function impairment
No
Description
21-year-old HIV positive patient, known for ilicit substance abuse and recent HIV infection. Clinical history relevant for chronic psychotic disorder (poorly characterized) treated with aripiprazole 10mg/d orally since 2017. Following HIV diagnosis, he initiated FTC/TAF + RAL to avoid drug-drug-interactions, but later genotype showed resistance mutations for RAL (163K substitution in 98% of the sequences).
ARV regimen was changed to DRV/c/FTC/TAF in November 2018, and the dose of aripiprazole was reduced to 5mg/d. Clinical response continued to be adequate and no side effects were observed. VL became undetectable afetr 3 months of follow-up.
Aripiprazole is metabolized by CYP3A4 and CYP2D6. Darunavir/cobicistat could potentially increase aripiprazole concentrations, but no adverse effects were observed in our patient with dose modification (10 mg to 5mg) when cobicistat was introduced.
Outcome
No unwanted outcome
Editorial Comment
Aripiprazole is metabolized by CYP3A4 and CYP2D6. Darunavir/cobicistat could potentially increase aripiprazole concentrations. The European product label for aripiprazole advises reducing the aripiprazole dose to approximately one-half of its prescribed dose when given with potent inhibitors of CYP3A4, as in this case.