[Incidence of adverse drug reactions in patients initiating or changing antiretroviral therapy]

Abstract

Background: In the Chilean AIDS Cohort, the 15.9% of the patients change the first scheme of HAART because of toxicity, which is also the cause of 47% suspensions of treatment occurred in the first months of therapy.

Aim: To analyze the incidence and causality of adverse drug reactions in patients initiating or changing antiretroviral therapy.

Materials and methods: 92 patients who started or changed antiretroviral treatment in a period from May to July 2011 were followed to detect adverse drug reactions.

Results: 75% (n: 69) of patients had at least one adverse event. From a total of 76 adverse drug reactions detected the most frequent ones were diarrhea (21.1%, n: 16) and hyperbilirubinemia (19.7% n: 15). 85.9% of the adverse events where grade depending on its seriousness, 34.1% had grade 1 toxicity, 32.9% grade 2, 9.4% grade 3 and only 3.5% grade 4. Only 22 patients (31.8%) required a treatment change. The most frequent causes for changing treatment were because of anaemia by AZT (45.4%, n: 10) and diarrhea associated with the use of LPV/r (27.3%, n: 6).

Conclusion: Knowing the real incidence rate of adverse drug reactions may help the health team giving proper management and monitoring of these reactions in the patient, in order to avoid an early change of HAART. Defining a multidisciplinary team which includes a pharmacist is essential for proper pharmacosurveillance.