Variation in Drug Interactions in People With HIV (PLWH) Aged 60 Years and Older on Stable Antiretroviral Therapy Making a Switch to Bictegravir/Tenofovir Alafenamide/Emtricitabine

The introduction of integrase inhibitors into clinical practice has greatly improved the efficacy and tolerability of modern antiretroviral combination therapies for the treatment of patients with HIV-1 infection. Indeed, these drugs have shown in registration studies high antiviral potency associated with a negligible incidence of short- and long-term adverse events, so much so that they are consistently included in the drug regimens recommended by all international guidelines for the treatment of HIV-positive patients naive to antiretroviral therapy.

Several cohort studies have recently shown a significant increase in the mean age of PLWH ( People Living With HIV) and in the prevalence of people in advanced age in the various cohorts, as a result of the marked increase in the mean life expectancy of these people achieved by modern antiretroviral combination therapies.

PLWH in advanced age, however, have a high prevalence of noninfectious comorbidities (cardiovascular disease, metabolic abnormalities, chronic renal failure, osteopenia-osteoporosis, neoplastic diseases, etc.), brought about by age-related aging but also by their accelerated biological aging caused by HIV infection and associated chronic inflammation and immunoactivation.

The high prevalence of comorbidities exposes PLWH in old age to the need to take multiple drug treatments in addition to antiretroviral therapy, with the gradually increasing risk of unfavorable pharmacokinetic interactions between antiretroviral drugs and drugs taken to treat the comorbidities.

The effect of such interactions can be either a reduction in plasma concentrations with reduced efficacy of antiretroviral drugs or an increase in plasma levels of concomitant drugs and the risk of toxicity induced by them.