A Study of Potential drug-drug interactions in HIV positive individuals with Co-morbidities

The high prevalence of comorbid conditions, both communicable and non-communicable, in HIV patients dictate the need for prescription of additional medications which makes way for the possibility of a particular medication altering the intensity of the pharmacotherapeutic effect of a concomitantly administered medication, a potential drug-drug interaction (PDDI), which can lead to the precipitation of adverse effects and even treatment failure. In this retrospective observational study, data was collected from medical records of adult HIV positive patients on antiretroviral therapy (ART) with comorbidities who visited the hospital between January, 2015 and June, 2017. Using the University of Liverpool drug-interaction database, the identified interactions were classified into three categories. The category of PDDI requiring monitoring, dose adjustment or adjustment of time of dosing was taken and evaluated for the type of interaction, risk and prevalence. Time of onset and severity was determined using Micromedex drug-interaction database. Data analysis was done using descriptive statistics and binomial logistic regression was used for risk estimation. In this study, a total of 244 people were enrolled. A total of 711 PDDIs were identified. By analysing risk ratio, patients with more than 5 concomitant medications, protease inhibitor-based ART regimen, duration of illness (≥6 years), cardiovascular disease and presence of coinfections were at a higher risk of development of PDDIs. Pharmacokinetic PDDIs (87.2%) were higher in comparison to pharmacodynamic PDDIs (12.8%). Awareness among prescribers of this silent but important occurrence will help in recognition, prevention and management of PDDI which might otherwise complicate the therapeutic outcome.