Type B lactic acidosis in an AIDS patient treated with zidovudine

Human immunodeficiency virus type 1 (HIV 1) infection has been shown to cause myopathy. Zidovudine, a nucleoside analogue, has also been shown to cause myopathy in HIV-infected patients. Dalakas et al., were unable to distinguish the myopathy associated with HIV infection from the toxic mitochondrial myopathy caused by zidovudine. In a recent report, Chattha et al., described seven patients with Acquired Immunodeficiency Syndrome (AIDS) who developed type B lactic acidosis. Four of these patients were treated with zidovudine. A 100% mortality over a period of 15 months was observed. Zidovudine disrupts the mitochondrial deoxyribonucleic acid (DNA) that encodes for the respiratory chains, inhibiting the transport of lactate into the mitochondria. This may cause the accumulation of lactate in the cytoplasm, producing a severe metabolic acidosis. We present an AIDS patient with servere type B lactic acidosis which could have been associated with, or precipitated by, zidovudine.