Symptomatic hyperlactataemia precipitated by the addition of tetracycline to combination antiretroviral therapy

Hyperlactataemia in the setting of combination antiretroviral therapy for HIV infection occurs on a spectrum ranging from common, asymptomatic laboratory abnormalities to rare, potentially life-threatening lactic acidosis. Some other medications, including the biguanides, tetracycline, and even linezolid, have rarely been reported to cause lactic acidosis. Recently, cases of lactic acidosis or hyperlactataemia have been reported in patients receiving combination antiretroviral therapy that have been precipitated by the addition of other medications - eg, metformin or ribavirin. We report a case of symptomatic hyperlactataemia in a patient on combination antiretroviral therapy that was likely precipitated by the addition of tetracycline and discuss the broader implications of other medications with the potential to cause hyperlactataemia in the setting of combination antiretroviral therapy.