Date of report 09 Mar 2020
Reported case interaction between
Nevirapine and Dexamethasone
Nevirapine and Dexamethasone
Drugs suspected to be involved in the DDI
Complete list of drugs taken by the patient
Dexamethasone, 5-Fluorouracil, Oxaliplatin, Bevacizumab, Atorvastatnin
Clinical case description
55 year-old woman diagnosed with HIV in 1990 . She initiated ART in 1990 and plasma viral load had been under the limit of detection since 2001. Since 2011 she had been receiving ART with abacavir, lamivudine and nevirapine. In 2017 she was diagnosed with colorectal cancer. As first line therapy she received neoadjuvant radiotherapy and chemotherapy with capecitabine followed by surgical resection and chemotherapy with capecitabine. Some months later disease progression was observed, and a new chemotherapy scheme was initiated that included 5-Fluorouracil and Oxaliplatin in combination with Bevacizumab. Every treatment cycle chemotherapy was administered along with dexamethasone at a dose of 20 mg, as induction, followed by 4 mg twice daily for 3 days. A routine HIV control was performed after 11 cycles and plasma viral load was 515 copies/mL. The patien reported good adherence to ART, with no missed doses. A genotypic resistance test showed NRTI and NNRTI resistance-associated mutations (V75I, M184V and K101E). ART was switched to TAF/FTC/DRV/c, achieving undetectable plasma viral load.
Clinical Outcome
Drug Interaction Probability Scale (DIPS)
Editorial Comment
Coadministration of Nevirapine (NVP) and Dexamethasone may decrease NVP and/or Dexamethasone plasma concentrations. To anticipate/characterize the drug-drug interaction, it is recommanded to monitor NVP plasma concentrations and steroid effects (not reported in the present case) At failure, the genotypic test performed on the corresponding plasma HIV-RNA (515 copies/mL) demonstrated a M184V mutation associated with 3TC/FTC resistance and with ABC partial resistance. It harbored also a K101E, which confered NVP resistance, potentially associated with low NVP plasma exposure. The Genotypic Sensitivity Score (GSS) is calculated to 0.5, explaining the virological failure related with the drug interaction. The switch from NVP + ABC/3TC to FTC/TAF/DRV/c (GSS = 2) and Dexamethasone discontinuation, led to a virological resuppression.
University of Liverpool Recommendation
Potential interaction - may require close monitoring, alteration of drug dosage or timing of administration