Building the best regimen for highly treatment-experienced patients

The use of highly active antiretroviral therapy (HAART) has dramatically reduced the mortality and morbidity associated with HIV infection. However, drug resistance remains the most important reason for virological failure and rapidly limits treatment options. Virus resistant to all three major antiretroviral drug classes is now reported even in primary seroconverters. In this article, the options for the management of highly treatment-experienced patients with multiple drug resistance are considered. Options discussed include whether to continue failing therapy, stop treatment in the hope of the virus reverting to wild type, the role of resistance testing in this setting, the impact of reduced viral fitness and the use of mega- and giga-HAART.