Date of report: 20 Nov 2020
Reported case interaction between
 Raltegravir and Enzalutamide

FLS Science

Drugs suspected to be involved in the DDI

Drug A
Raltegravir (Victim)
Daily Dose
1200 (mg)
Dose adjustment performed
No
Administration Route
Oral
Start date
Oct. 22, 2015
End date
Ongoing
Drug B
Enzalutamide (Perpetrator)
Daily Dose
160 (mg)
Dose adjustment performed
No
Administration Route
Oral
Start date
Feb. 5, 2016
End date
Ongoing

Complete list of drugs taken by the patient

Antiretroviral treatment
Abacavir/Lamivudine
Raltegravir
Complete list of all comedications taken by the patient, included that involved in the DDI
Enzalutamide 160mg OD Abiraterone 1g OD Amlodipine 10mg OD Metformin Rosuvastatin 20mg OD Travoprost eye drops

Clinical case description

Gender
Male
Age
73
eGFR (mL/min)
>60
Liver function impairment
No
Description
Patient was started on enzalutamide and abiraterone in Feb 2016 for prostate cancer. Patient was taking ABC/3TC/RAL 400mg BD at the time. Virological suppression was maintained throughout oncological treatment, including when the patient switched to RAL 1200mg OD in March 2018. The patient is currently still on enzalutamide and ABC/3TC/RAL 1200mg OD.

Outcome

No unwanted outcome

Editorial Comment

Enzalutamide is a strong CYP3A4 inducer and a moderate CYP2C9 and CYP2C19 inducer in humans. UGT1A1 may be induced as well. Although viral suppression was maintained in this case, close monitoring and maybe TDM and/or bid dosing of raltegravir might be considered in this scenario.