Metformin-Associated Lactic Acidosis (MALA): When a Common Drug Turns Catastrophic.

Metformin, a first-line agent in the treatment of type 2 diabetes mellitus, is widely favored for its efficacy and safety profile; however, under conditions of impaired renal function, it can lead to metformin-associated lactic acidosis (MALA), a rare but life-threatening complication. The diagnosis requires careful exclusion of other causes of lactic acidosis, such as sepsis or hypoperfusion, which can mimic MALA. We present a case of an 88-year-old female with type 2 diabetes and chronic kidney disease (CKD) stage III who developed severe lactic acidosis and encephalopathy in the setting of acute kidney injury and recent infection. The patient's condition rapidly deteriorated despite broad-spectrum antibiotics and hemodynamic support. Emergent dialysis resulted in significant clinical and biochemical improvement, supporting a diagnosis of MALA. This case emphasizes the importance of early recognition of MALA, particularly in vulnerable populations with evolving renal dysfunction. We present the pathophysiology, diagnostic approach, and management strategies for MALA. The timely initiation of renal replacement therapy remains critical for reversing metabolic derangements and improving outcomes.