Abstract: TH-PO0385
Metformin in Focus: Systematic Review of Lactic Acidosis Risk and Outcomes, 2015-2025
Session Information
- Fluid, Electrolyte, and Acid-Base Disorders: Clinical - 1
November 06, 2025 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Fluid, Electrolytes, and Acid-Base Disorders
- 1102 Fluid, Electrolyte, and Acid-Base Disorders: Clinical
Authors
- Vasudev, Ishita, BronxCare Health System, New York, New York, United States
- Bhardwaj, Akinchan, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, PY, India
Background
Metformin is a first-line treatment for type 2 diabetes. Metformin-associated lactic acidosis (MALA) is a rare but life-threatening complication, defined by elevated lactate (>5 mmol/L) and metabolic acidosis (pH <7.35) in patients on metformin. Although its incidence is extremely low (only a few cases per 100,000 patient-years), MALA carries a high mortality risk and usually occurs in the presence of precipitating factors. We systematically reviewed human studies from 2015–2025 to characterize the incidence, risk factors, clinical features, management strategies, and outcomes of MALA.
Methods
We conducted a systematic review adhering to PRISMA guidelines, using PubMed, Google Scholar, Scopus and Embase (2015–2025) to identify human studies on MALA, excluding preprints and qualitatively synthesized the findings.
Results
MALA remains very rare; nearly all cases had a precipitating factor—most commonly renal impairment—and also liver dysfunction, alcohol use, dehydration, or acute illness (e.g., sepsis). Clinically, MALA typically presents with severe high–anion gap metabolic acidosis and markedly elevated lactate levels (often >10 mmol/L), accompanied by non-specific symptoms such as gastrointestinal distress, Kussmaul respirations, hypotension and altered mental status. Management focuses on prompt metformin cessation and intensive supportive care ; severe cases often require early hemodialysis to enhance drug and lactate clearance. Despite treatment, mortality is approximately 30–40% and poor prognosis correlates more with the severity of the underlying critical illness than with serum metformin levels.
Conclusion
MALA is an uncommon yet frequently fatal complication of metformin therapy. While the risk is extremely low, most cases occur in patients with identifiable risk factors (especially renal dysfunction, severe sepsis). Clinicians should remain vigilant for MALA in metformin users with unexplained lactic acidosis and initiate rapid treatment—including hemodialysis when indicated—to improve outcomes.