Profile of drug-drug interactions and impact on the effectiveness of antiretroviral therapy among patients living with HIV followed at an Infectious Diseases Referral Center in Belo Horizonte, Brazil.

HIV infection may be considered a chronic condition for people living with HIV with access to antiretrovirals and this has effectively increased survival. Moreover, this has also facilitated the emergence of other comorbidities increasing the risk for drug-drug interactions and polypharmacy. The profile of these interactions as well as their consequences for people living with HIV are still not completely elucidated. The objectives of this study were to describe the profile of these interactions, their prevalence and their classification according to the potential for significant or non-significant drug-drug interactions. From June 2015 to July 2016, people living with HIV on follow-up at an Infectious Diseases Referral Center in Belo Horizonte, Brazil have been investigated for the presence of drug-drug interactions. A total of 304 patients were included and the majority (75%) had less than 50 years of age, male (66.4%), and 37.8% self-defined as brown skinned. Approximately 24% were on five or more medications and half of them presented with drug-drug interactions. Patients older than 50 years had a higher frequency of antiretrovirals drug-drug interactions with other drugs compared to younger patients (p=0.002). No relationship was found between the number of drug-drug interactions and the effectiveness of antiretrovirals. As expected, the higher the number of non-HIV medications used (OR=1.129; 95%CI 1.004-1.209; p=0.04) was associated with an increase in drug-drug interactions. The high prevalence of drug-drug interactions found and the data collected should be useful to establish measures of quaternary prevention and to increase the medication security for people living with HIV.