No effects of nirmatrelvir/ritonavir on darunavir plasma trough concentrations: a case report

COVID-19 may be associated with worst outcomes in people living with HIV compared with HIV-negative patients. Nirmatrelvir/ritonavir can be safely co-administered with all the HIV antiretroviral drugs, without considering dose adjustment. However, no studies have formally investigated the effect of a double booster (ritonavir plus cobicistat) regimen on darunavir concentrations. We presented a case describing the lack of effects of adding nirmatrelvir/ritonavir on darunavir plasma trough concentrations in a patient with HIV already on treatment with a booster-based antiretroviral regimen. We believe this could be a reassuring message for physicians, allowing them to prevent unnecessary denial of COVID-19 treatment or inappropriate discontinuation of co-medications in patients with HIV.