Background Antiretroviral therapy (ART) has markedly decreased the morbidity and mortality due to HIV. However, toxicity, comorbidity and treatment failure, among others, may result in frequent initial ART regimen change.

Purpose To identify and analyse the changes in ART and the reasons for it in HIV patients over two years of follow-up in our hospital.

Materials and Methods We retrospectively reviewed all patients who attended the outpatients pharmaceutical care unit who received ART during a two-year period (2010–2011)

For each patient whose ART was changed we created a database of pharmaceutical care and recorded and analysed the following data: previous and new treatment, reason for treatment change, viral load, CD4 cell count, resistance profile and differential cost of change.

Results The table below summarises the total of patients reviewed

The most frequent reason for change was adverse reaction to treatment 15 patients (38.4%); the most common were dyslipidaemia (5 cases) and neuropsychiatric disorders (4 cases); the other reasons were simplification of antiretroviral therapy 10 patients (25.6%), treatment failure 4 patients (10.2%), resistance to treatment 4 patients (10.2%) and other causes 6 patients (15.4%) (noncompliance, interactions, cardiovascular risk and unknown).The most common treatment regimens preceding the change were tenofovir/emtricitabine (TDF/FTC) + lopinavir/ritonavir (LPV/r) and tenofovir/emtricitabine/efavirenz (TDF/FTC/EFV) (6 and 5 patients respectively), after the change tenofovir/emtricitabine (TDF/FTC) + darunavir/ritonavir (DRV/r) 600/100 mg was the most usual regimen (7 patients).

The average monthly differences in cost per patient after a change of antiretroviral treatment were 125.5 and 99.0 euros in 2010 and 2011 respectively.

Conclusions The identification and description of the changes in ART can act as a support tool in the overall monitoring of HIV patients.

It should be noted that adverse effects and desire to simplify ART contribute greatly to the reasons for change.

No conflict of interest.