ART failure and strategies for switching ART regimens in Europe.

The introduction of combination antiretroviral therapy (cART) represents a major turning point in the response to the HIV/AIDS epidemic. WHO European Region Member States have made significant progress in scaling up access to such treatment. By mid-2007, cART was available in the public sector health services in every country of the Region except Turkmenistan, with coverage estimated as very high (more than 75% of those in need of treatment) in at least 38 out of 53 Member States (1). Though countries in eastern Europe and central Asia1 have initiated the delivery of standardized first-line antiretroviral therapy (ART), as recommended by WHO, several key issues in the clinical management of patients remained unresolved as there has been no consensus among experts on a number of issues including: how virological failure to cART is defined; what HIV-RNA threshold level constitutes virological failure; what constitutes an early or late switch when cART no longer completely suppresses viral replication and what impact each has on the spread of drug-resistant (DR) HIV; when is the optimal time to switch to ART in case of a lack of complete viral suppression; and what role resistance testing of HIV has in determining when to switch and which treatment regime to switch to. WHO’s public health approach to cART is first and foremost to extend life, and then to have one evidence-based global standard for using cART. This consists of one first-line cART regimen. If this fails, one second-line cART regimen is employed (then salvage cART if available); utilisation of three orally available drug classes; simplicity of drug combinations (including fixed-dose combinations); straightforward recommendations for switch timing and toxicity substitutions; consideration of the Letter to the Editor ART FAILURE AND STRATEGIES FOR SWITCHING ART REGIMENS IN EUROPE