Lactic acidosis in an HIV-infected patient receiving highly active antiretroviral therapy

Background: A 51-year-old man with HIV infection on highly active antiretroviral therapy presented with abdominal pain and exertional dyspnea. Physical examination revealed increased respiration and cachexia. Laboratory tests showed a lactic acid concentration elevated to 6.4 mM. Investigation: Physical examination, blood chemistry, arterial blood gas, urine analysis, chest X-ray, and ultrasound of liver. Diagnosis: Nucleoside reverse transcriptase inhibitor (NRTI)-induced lactic acidosis, hepatitis and chemical pancreatitis. Proximal renal tubular acidosis with Fanconi's syndrome, secondary to treatment with tenofovir. Management: The patient was supported on intravenous and oral bicarbonate, riboflavin and phosphorus supplementation. Highly active antiretroviral therapy was discontinued. The patient's lactate level decreased about 2 weeks after discharge.