Evaluation of drug interactions and their impact on virological failure of people living with HIV/AIDS over 50 years of age / Avaliação das interações medicamentosas e seu impacto no fracasso virológico de pessoas vivendo com HIV/AIDS acima de 50 anos de idade

Abstract

The discovery of the antiretroviral therapy (ART) increased life expectancy of people living with HIV (PLHIV). This chronic condition was associated with other diseases with a higher risk of multiple drug use and drug interactions. Drug interactions can cause therapy failures and side effects. This cross-sectional study was carried out in three specialized clinics located in the northwestern of the state of Sao Paulo from September to December 2019, and evaluated the potential drug interactions in PLHIV and its impact on virological failure. PLHIV aged 50 years or older were included, using ART and other drugs for more than one year and viral load tests in the last 6 months. The data were obtained through a structured questionnaire and medical records. The interactions were analyzed by the Liverpool drug interaction database. The virological failure was defined as two exams of viral loads above 200 copies/ml. We performed a descriptive analysis of the results. Among the 113 people included in the study, 43.36% acquired the virus after the age of 50 and 61.95% reported had never stopped using ART. There were comorbidities (89.38%), the main ones: arterial hypertension (47.79%), diabetes (20.35%) and depression (17.70%). The drug interactions appeared in 74.34% of the respondents and 7.08% presented contraindicated interactions. The drugs involving the central nervous system were responsible for most interactions (47.58%), followed by antihypertensive drugs, hypoglycemic drugs and statins. Protease inhibitors and non-nucleoside reverse transcriptase inhibitors showed a higher number of interactions. Only three individuals (2.65%) showed virological failure, two of which presented adherence failure. Drug interactions were very prevalent among individuals with HIV/AIDS over 50 years of age and these interactions have the potential to change mainly the comedication concentration and have no significant impact on virological failure.