Abstract:Lipodystrophy complications, including lipoatrophy (pathological fat loss) and metabolic complications, have emerged as important long-term toxicities associated with antiretroviral therapy in the current era. The wealth of data that has accumulated over the past 6 years has now clarified the contribution of specific antiretroviral drugs to the risk of these clinical endpoints, with evidence that lipoatrophy is strongly associated with the choice of nucleoside reverse transcriptase inhibitor therapy (specifically, stavudine and to a lesser extent zidovudine). The aetiological basis of metabolic complications of antiretroviral therapy has proven to be complex, in that the risk appears to be modulated by a number of lifestyle factors that have made the metabolic syndrome highly prevalent in the general population, with additional contributions from HIV disease status itself, as well as from individual drugs within the HIV protease inhibitor class. The currently licensed non-nucleoside reverse transcriptase inhibitor (NNRTI) drugs, efavirenz and nevirapine, have been proven to have a favourable safety profile in terms of lipodystrophy complications. However, it must be noted that NNRTI drugs also have individual toxicity profiles that must be accounted for when considering and/or monitoring their use in the treatment of HIV infection.
Full Text:This review will focus specifically on the topic of non-nucleoside reverse transcriptase inhibitor (NNRTI) therapy and its possible association with lipodystrophy complications in patients with HIV. Given the multifactorial nature of the HIV lipodystrophy syndrome, which encompasses a number of complications including lipoatrophy and visceral and/or localised fat accumulation, as well as metabolic complications, it is gratifying to be able to provide a simple negative answer to the question under review here. In short, NNRTI drugs do not contribute to the risk of any component of lipodystrophy--indeed, nevirapine and efavirenz have emerged as having unexpected beneficial effects on lipid profiles, so that they may have a role in the management of metabolic complications that have arisen in the presence of other antiretroviral drugs.However, it remains important to consider the factors that do contribute to the various manifestations of HIV lipodystrophy in order to understand the potential benefits that may be expected with NNRTI therapy. For example, the concept of 'switching' from HIV protease inhibitors (PIs) to NNRTI drugs has been advocated for some time as a potential remedy for lipodystrophy complications. Here, we will examine the evidence suggesting that this strategy may be a rational approach to managing metabolic complications, particularly the atherogenic lipid profile characterised by reduced high-density lipoprotein (HDL)-cholesterol levels, but that lipoatrophy is unlikely to improve in this scenario.
Non-Nucleoside Reverse Transcriptase Inhibitor (NNRTI) Therapy and LipoatrophyEnormous progress has been made in understanding the 'lipodystrophy syndr...