title: Adverse drug reactions to antiretroviral therapy (ARVs): incidence, type and risk factors in Nigeria.
abstract: BACKGROUND
  Data on adverse drug reactions (ADRs) related to antiretroviral (ARV) use in public health practice are few indicating the need for ART safety surveillance in clinical care.
  
  
  OBJECTIVE
  To evaluate the incidence, type and risk factors associated with adverse drug reactions (ADRs) among patients on antiretroviral drugs (ARV).
  
  
  METHODS
  Patients initiated on ARVs between May 2006 and May 2009 were evaluated in a retrospective cohort analysis in three health facilities in Nigeria. Regimens prescribed include nucleoside backbone of zidovudine (AZT)/lamivudine (3TC), stavudine (d4T)/3TC, or tenofovir (TDF)/3TC in combination with either nevirapine (NVP) or efavirenz (EFV). Generalized Estimating Equation (GEE) model was used to identify risk factors associated with occurrence of ADR.
  
  
  RESULTS
  2650 patients were followed-up for 2456 person-years and reported 114 ADRs (incidence rate = 4.6/100 person-years).There were more females 1706(64%) and 73(64%) of the ADRs were reported by women. Overall, 61(54%) of ADRs were reported by patients on AZT with 54(47%) of these occurring in patients on AZT/NVP. The commonest ADRs reported were pain 25(30%) and skinrash 10(18%). Most ADRs were grade 1(39%) with only 1% being life threatening (grade 4). Adjusted GEE analysis showed that ADR was less likely to occur in patients on longer duration of ART compared to the first six months on treatment; 6-12 months AOR 0.38(95% CI:0.16-0.91) and 12-24 months AOR 0.34(95% CI:0.16-0.73) respectively. Compared to patients on TDF, ADR was less likely to occur in patients on d4T and AZT AOR 0.18(95% CI 0.05-0.64) and AOR 0.24(95% CI:0.7-0.9) respectively. Age, gender and CD4 count were not significantly associated with ADRs.
  
  
  CONCLUSIONS
  ADRs are more likely to occur within the first six months on treatment. Close monitoring within this period is required to prevent occurrence of severe ADR and improve ART adherence. Further research on the tolerability of tenofovir in this environment is recommended.
authors.affiliation: Department of Operations Research, HIV/AIDS Program, Population Council, Nigeria, Plot 759, Cadastral Zone AO, Off Constitution Avenue, Central Business District, Abuja, Nigeria. dreluwag@gmail.com
authors.forename: George I
authors.initials: GI
authors.lastname: Eluwa
authors.forename: Titilope
authors.initials: T
authors.lastname: Badru
authors.forename: Kenneth A
authors.initials: KA
authors.lastname: Agu
authors.forename: Kesiena J
authors.initials: KJ
authors.lastname: Akpoigbe
authors.forename: Otto
authors.initials: O
authors.lastname: Chabikuli
authors.forename: Christoph
authors.initials: C
authors.lastname: Hamelmann
mesh_terms: D000225:Adenine / Q000009:adverse effects / Q000031:analogs & derivatives; D000293:Adolescent; D000328:Adult; D000480:Alkynes; D044966:Anti-Retroviral Agents / Q000009:adverse effects*; D048588:Benzoxazines / Q000009:adverse effects; D015331:Cohort Studies; D003521:Cyclopropanes; D064420:Drug-Related Side Effects and Adverse Reactions / Q000453:epidemiology*; D005076:Exanthema / Q000139:chemically induced*; D005260:Female; D015658:HIV Infections / Q000188:drug therapy*; D006801:Humans; D015994:Incidence; D019259:Lamivudine / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D019829:Nevirapine / Q000009:adverse effects; D009549:Nigeria / Q000453:epidemiology; D063065:Organophosphonates / Q000009:adverse effects; D010146:Pain / Q000139:chemically induced*; D012189:Retrospective Studies; D012307:Risk Factors; D018119:Stavudine / Q000009:adverse effects; D000068698:Tenofovir; D015215:Zidovudine / Q000009:adverse effects
chemical_list: D000480:Alkynes; D044966:Anti-Retroviral Agents; D048588:Benzoxazines; D003521:Cyclopropanes; D063065:Organophosphonates; D019259:Lamivudine; D015215:Zidovudine; D019829:Nevirapine; D000068698:Tenofovir; D018119:Stavudine; D000225:Adenine; C098320:efavirenz