Pharmacoepidemiological approach to the predisposing factors for highly active antiretroviral therapy failure in an HIV-positive cohort from Cordoba City (Argentina) 1995–2005

Highly active antiretroviral therapy (HAART) restores immunity avoids resistance and delays disease progression. Nonetheless adverse medicament reactions (AMRs) and therapeutic failure (TF) are still deleterious events. Consequently their predisposing factors should be evaluated. Data from 181 men and 28 women of an Argentinean cohort (1995-2005) were collected and analysed by logistic regression studying 63 schemes (15 active principles). The AMRs were the main cause of scheme change followed by TF and medicament simplification without influence of age and sex. Twenty-nine schemes exhibited TF at least once. Compared with zidovudine-lamivudine-nevirapine (success: >75%) the following schemes fail more frequently (P or= 3 protease inhibitors (11-fold). Inadequate patient adherence preceded failure (>95%) but not successful treatments with a strong AMR-TF association (P < 0.005). Although some schemes had inherently increased TF low adherence drug toxicity and TF were critically interrelated interfering with HAART goals.