Linezolid-Induced Lactic Acidosis: A Potentially Preventable Life-Threatening Complication

Linezolid, an antibiotic commonly used for multi-drug-resistant (MDR) bacterial infections, inhibits bacterial protein synthesis and growth and is widely used for treating methicillin-resistant Staphylococcus Aureus (MRSA). Common side effects include nausea, diarrhoea, neuropathies, and bone marrow suppression. Rarely, linezolid can lead to a potentially fatal side effect of lactic acidosis (LA), the most common cause of high anion gaps metabolic acidosis (HAGMA). This report presents a case of an elderly female, who was brought to the emergency department (ED) with drowsiness as the only symptom, with severe LA found on blood work-up secondary to prolonged linezolid usage. Here, we provide an overview of the presentation and recognition of this rare adverse effect in this patient. Treating physicians should remain vigilant while prescribing such medications for longer duration with frequent monitoring for this preventable life-threatening complication.