title: Comparative durability of nevirapine versus efavirenz in first-line regimens during the first year of initiating antiretroviral therapy among Swaziland HIV-infected adults.
abstract: Nevirapine (NVP) and Efavirenz (EFV) have generally comparable clinical and virologic efficacy. However, data comparing NVP durability to EFV are imprecise. We analyzed cohort data to compare durability of NVP to EFV among patients initiating ART in Mbabane, Swaziland. The primary outcome was poor regimen durability defined as any modification of NVP or EFV to the ART regimen. Multivariate Cox proportional hazards models were employed to estimate the risk of poor regimen durability (all-cause) for the two regimens and also separately to estimate risk of drug-related toxicity. We analyzed records for 769 patients initiating ART in Mbabane, Swaziland from March 2006 to December 2007. 30 patients (3.9%) changed their NVP or EFV-based regimen during follow up. Cumulative incidence for poor regimen durability was 5.3% and 2.7% for NVP and EFV, respectively. Cumulative incidence for drug-related toxicity was 1.9% and 2.7% for NVP and EFV, respectively. Burden of TB was high and 14 (46.7%) modifications were due to patients substituting NVP due to beginning TB treatment. Though the estimates were imprecise, use of NVP - based regimens seemed to be associated with higher risk of modifications compared to use of EFV - based regimens (HR 2.03 95%CI 0.58 - 7.05) and NVP - based regimens had a small advantage over EFV - based regimens with regard to toxicity - related modifications (HR 0.87 95%CI 0.26 - 2.90). Due to the high burden of TB and a significant proportion of patients changing their ART regimen after starting TB treatment, use of EFV as the preferred NNRTI over NVP in high TB endemic settings may result in improved first-line regimen tolerance. Further studies comparing the cost-effectiveness of delivering these two NNRTIs in light of their different limitations are required.
authors.affiliation: Clinical HIV Research Unit, Department of Internal Medicine, School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand, South Africa.
authors.forename: Simbarashe
authors.initials: S
authors.lastname: Takuva
authors.forename: Denise
authors.initials: D
authors.lastname: Evans
authors.forename: Khangelani
authors.initials: K
authors.lastname: Zuma
authors.forename: Velephi
authors.initials: V
authors.lastname: Okello
authors.forename: Goedele
authors.initials: G
authors.lastname: Louwagie
mesh_terms: D000328:Adult; D000480:Alkynes; D019380:Anti-HIV Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D048588:Benzoxazines / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D015331:Cohort Studies; D003521:Cyclopropanes; D013541:Eswatini; D005260:Female; D005500:Follow-Up Studies; D015658:HIV Infections / Q000188:drug therapy*; D006801:Humans; D015994:Incidence; D008297:Male; D015999:Multivariate Analysis; D019829:Nevirapine / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D018894:Reverse Transcriptase Inhibitors / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use; D016896:Treatment Outcome; D014376:Tuberculosis / Q000453:epidemiology
chemical_list: D000480:Alkynes; D019380:Anti-HIV Agents; D048588:Benzoxazines; D003521:Cyclopropanes; D018894:Reverse Transcriptase Inhibitors; D019829:Nevirapine; C098320:efavirenz
keywords: Antiretroviral therapy; Efavirenz; Nevirapine; Resource limited setting; Swaziland; Tolerability; Toxicity