Laboratory-Confirmed Metformin-Associated Lactic Acidosis

Area of Science:

• Internal Medicine
• Pharmacology
• Critical Care Medicine

Background:

• Metformin is a first-line oral hypoglycemic agent for type 2 diabetes.
• Metformin-associated lactic acidosis (MALA) is a rare but severe adverse effect.
• Accurate diagnosis can be challenging due to limited laboratory testing.

Observation:

• Three cases of MALA were prospectively identified and confirmed by laboratory testing.
• Patients presented with severe lactic acidosis and elevated metformin levels.
• All three patients required intensive care unit admission for supportive treatment.

Findings:

• Two out of three patients with MALA died despite intensive care and continuous venovenous hemodialysis (CVVHD).
• Elevated metformin levels were confirmed in all three cases, ranging from 3.9 to 48.7 mg/L.
• The severity of acidosis (pH 6.7-6.95) and lactate levels (14.8-27.6 mmol/L) indicated critical illness.

Implications:

• This case series underscores the critical importance of judicious metformin prescription, especially in patients with risk factors.
• Diagnostic challenges associated with MALA necessitate increased awareness and accessible laboratory confirmation methods.
• Inappropriate prescription in specific patient populations can lead to severe outcomes, emphasizing the need for careful patient selection and monitoring.