Occurrence of adverse drug reactions in patients taking tenofovir and efavirenz at a public central hospital in Zimbabwe

Abstract

Background: Tenofovir, lamivudine and efavirenz is the recommended first-line treatment for HIV in resource-limited countries. However, tenofovir and efavirenz have significant adverse reactions, which have not been adequately studied in Zimbabwe.

Aim: To determine the extent of occurrence of adverse drug reactions in patients taking tenofovir and efavirenz at a large public hospital in Zimbabwe.

Setting: Harare central hospital opportunistic infections clinic.

Methods: A cross sectional survey of 100 conveniently sampled HIV-positive adult patients was carried out. Study variables were socio-demographic factors, renal and Central Nervous System (CNS) adverse effects, treatment history and self-reported adherence.

Results: At least 1 renal and 1 CNS adverse effect were reported in 39% and 84% of participants respectively. Marital status was associated with occurrence of both renal (p=0.044) and CNS symptoms (p=0.039). Age was associated with occurrence of CNS symptoms (p=0.0004). Time on Antiretroviral Therapy (ART) (p=0.042), history of Urinary Tract Infection (UTI) (p=0.008), history of substance use (p=0.011) and history of mental illness (p=0.007) were associated with occurrence of renal symptoms.

Conclusion: Co-formulated tenofovir/lamivudine/efavirenz is the preferred first-line treatment for HIV infection due to high efficacy, low toxicity profile and once-daily dosing schedule. However, occurrence of renal and CNS adverse effects, based on the findings from this study was high. Adverse effects can be severe and irreversible. They can also cause non-adherence, resulting in viral replication, treatment failure and possible drug resistance. Regular monitoring of adverse effects in patients with history of urinary tract infections, substance use, mental illness and the elderly is required.