**1. Introduction**

Globally, in 2017, there were about 20.9 million HIV patients receiving highly active antiretroviral therapy (HAART) [1]. The treatment is targeted at inhibiting viral attachment and replication leading to the recovery of immune function [2, 3]. Since the introduction of HAART in 1996, there is a decline in mortality and morbidity associated with HIV [4, 5]. Due to HAART, the impact of HIV infection decreased [6] due to viral suppression, restoring and preserving immune function, improving quality of life, and reducing HIV related morbidity and mortality along the course of treatment [7–9]. There are a number of problems associated with HAART, including emergence of drug resistance, difficulties of maintaining longterm adherence, and drug-related toxicities [5] which lead to virological failure, immunological failure and clinical progression [10].

Virological failure increases the risk of clinical progression of HIV to AIDS [11]. World health organization (WHO) recommended combination therapy of HAART [12, 13]. The combination therapy improved the natural history of HIV infection from a life-ending event to a manageable chronic condition [14]. Adverse drug reactions (ADRs) associated with HAART resulted some considerable health consequences like co-morbidity with opportunistic infections [15–17].

Treatment failure to first-line regimens resulting from ADRs creates the need for very expensive and difficult-to-implement second-line regimens. Second-line HAART regimens are not easily affordable and largely donor dependent in resourcelimited settings [18]. Effective viral suppression is targeted by UNAIDS to meet "90-90-90" in 90% of persons on HAART by 2020 [19]. Use of an effective and safer HAART regimen helps to promote maximal viral suppression and improved immunological and virological response [20, 21].
