Mitochondrial AZT metabolism.

AZT remains an important drug to combat HIV infection in combination with other nucleoside analogs. However, long-term treatment with nucleoside analogs can result in mitochondrial toxicity, which can be fatal in some forms. We review the metabolic pathway for AZT transport and phosphorylation within mitochondria and its interaction with the mitochondrial DNA polymerase, Pol-gamma. Suggested mechanisms for the mitochondrial toxicity of AZT related to this metabolism are discussed. Finally we review recent evidence that the HIV virus itself is involved in the toxicity of AZT.