Effect of prescribed minimum benefits on the prevalence of possible drug-drug interactions of antiretroviral agents in a section of the private health care sector in South Africa: a 2 year comparative study

摘要

Objective The aim of this study was to determine the impact of prescribed minimum benefits (PMBs) after implementation, on the prevalence of possible drug-drug interactions (DDIs) between antiretrovirals (ARVs) themselves and other drugs on prescriptions claimed in a section of the private health care sector in South Africa.Setting A section of the private health care sector in South Africa.Method A comparative, retrospective drug-utilisation study was performed using 2004 and 2005 data from a medicine claims database. Possible DDIs found were classified according to Tatro (2005). Key findings The data consisted of 43 482 ARV prescriptions claimed during 2004 and 51 613 for 2005. A total of 5 305 882 and 3 606 992 medicine items were claimed during 2004 and 2005 respectively, of which 1.92% were ARVs for 2004 and 3.38% for 2005. Of 18 035 DDIs identified, 83.89% were between ARVs and other medications, and 16.11% were between ARVs themselves for 2004. Of 25 130 DDIs identified for 2005, 92.59% were between ARVs and other medications, and 7.41% were between ARVs themselves.Conclusions The decrease in DDIs between ARVs alone for 2005 as compared to 2004 could indicate a possible impact of PMBs on HIV/AIDS, as a chronic disease in which management programmes were introduced to ensure the appropriateness and effectiveness of drugs in HIV/AIDS. It is therefore recommended that further investigations be done on the management of the most important DDIs between ARVs alone and other drugs prescribed on the same prescription.