Date of report: 22 Jun 2020
Reported case interaction between
 Rilpivirine and Dexamethasone

FLS Science

Drugs suspected to be involved in the DDI

Drug A
Rilpivirine (Victim)
Daily Dose
25 (mg)
Dose adjustment performed
No
Administration Route
Oral
Start date
March 20, 2018
End date
Oct. 7, 2019
Drug B
Dexamethasone (Perpetrator)
Daily Dose
8 (mg)
Dose adjustment performed
No
Administration Route
Oral
Start date
Sept. 8, 2019
End date
Oct. 3, 2019

Complete list of drugs taken by the patient

Antiretroviral treatment
Rilpivirine/Emtricitabine/Tenofovir-DF
Complete list of all comedications taken by the patient, included that involved in the DDI
Dexamethasone, dexketoprofen

Clinical case description

Gender
Male
Age
58
eGFR (mL/min)
>60
Liver function impairment
No
Description
A 58-year-old patient with HIV infection since February 2018, on treatment with RPV/FTC/TDF. In September 2019 he was attended by a rheumatologist for an episode of arthritis and he was treated with dexamethasone (initially intravenously and then in a pattern of oral descent). When the patient came to our Unit in October 2019, he presented an HIV viral load of 2380 copies/ml and we assumed a possible treatment failure due to a drug to drug interaction and so we changed treatment to BIC/FTC/TAF.

Outcome

Loss of efficacy

Drug Interaction Probability Scale (DIPS)

Score
6 - Probable

Editorial Comment

Rilpivirine should not be co-administered with dexamethasone (more than a single dose) as significant decreases in rilpivirine plasma concentrations may occur due to CYP3A enzyme induction, which may result in loss of virologic response and possible resistance to rilpivirine or to the class of NNRTIs.