SHM Converge Scientific Abstract ePoster Gallery-Metformin-Associated Lactic Acidosis: A Serious Complication of a Common Drug

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This case describes a 76-year-old man with type 2 diabetes who developed metformin-associated lactic acidosis (MALA) after an acute kidney injury. He presented with abdominal pain, nausea, vomiting, poor oral intake, and constipation. Initial labs showed severe high anion gap metabolic acidosis, markedly elevated lactate, low bicarbonate, acute renal dysfunction, and hypoglycemia. His urinalysis suggested a urinary tract infection, and imaging showed significant stool burden but no hydronephrosis or hydroureter. Foley catheter placement returned 600 mL of urine.<br /><br />Because he was hemodynamically stable with little evidence of hypoperfusion, type A lactic acidosis was considered less likely. Type D lactic acidosis was also ruled out due to no history of bowel resection or short bowel syndrome. In the setting of continued metformin use with reduced renal clearance from AKI, type B lactic acidosis—specifically MALA—was the most likely diagnosis.<br /><br />Treatment included stopping metformin, giving IV fluids and bicarbonate, correcting hypoglycemia with oral glucose, treating the UTI with ceftriaxone, and starting a bowel regimen. His symptoms and laboratory abnormalities improved over the hospital course, including normalization of lactate, creatinine, bicarbonate, and anion gap.<br /><br />The report emphasizes that metformin is renally cleared and can increase lactate by inhibiting mitochondrial respiration, making patients with kidney dysfunction vulnerable to toxic accumulation. Clinicians should suspect MALA in patients taking metformin who present with severe lactic acidosis, acidemia, low bicarbonate, and renal impairment. Prompt recognition, medication review, and discontinuation of metformin are essential, and severe cases may require advanced support such as dialysis or extracorporeal therapies.

Asset Subtitle

Kanika Malani

Meta Tag

Author List Arkadiy Finn, Kanika Malani

Category Clinical Vignettes

Concept Metformin-Associated Lactic Acidosis

Concept Metformin

Concept Lactic Acidosis

Concept Renal Dysfunction

Concept Mitochondrial Respiration

Distinguished Non-Finalist

Presenter Organization Warren Alpert Medical School of Brown University

Presenting Author Kanika Malani

Track Adult

Keywords

metformin-associated lactic acidosis

MALA

acute kidney injury

type 2 diabetes

high anion gap metabolic acidosis

lactic acidosis

renal impairment

metformin toxicity

hypoglycemia

urinary tract infection

Metformin-Associated Lactic Acidosis

Metformin

Lactic Acidosis

Renal Dysfunction

Mitochondrial Respiration