Symptoms of lactic acidosis from metformin
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Symptoms of Lactic Acidosis from Metformin
Introduction to Metformin-Associated Lactic Acidosis (MALA)
Metformin is a widely used medication for managing type 2 diabetes mellitus. While it is generally considered safe, it can, in rare cases, lead to a serious condition known as metformin-associated lactic acidosis (MALA). This condition is characterized by elevated blood lactate levels and acidaemia, and it can be life-threatening if not promptly treated .
Gastrointestinal Symptoms
One of the most common and early signs of MALA is gastrointestinal distress. Patients often present with symptoms such as nausea, vomiting, abdominal pain, and diarrhea . These symptoms are frequently reported and can serve as initial indicators of the condition. In a study of patients admitted to an intensive care unit with MALA, all patients exhibited gastrointestinal symptoms, with many also showing signs of dehydration.
Fatigue and Weakness
Fatigue and generalized weakness are also common symptoms associated with MALA. These symptoms can be attributed to the body's inability to effectively utilize energy due to the impaired mitochondrial function caused by metformin . In one case report, a patient presented with significant fatigue and weakness following an overdose of metformin.
Metabolic Acidosis and Renal Dysfunction
Severe metabolic acidosis is a hallmark of MALA. Patients typically exhibit a low arterial pH, high anion gap, and elevated lactate levels . Acute renal dysfunction is also frequently observed, as evidenced by elevated serum creatinine levels . These metabolic disturbances are critical diagnostic markers and often necessitate urgent medical intervention, including hemodialysis .
Hemodynamic Instability
In severe cases, MALA can lead to hemodynamic instability, requiring vasopressor support and mechanical ventilation . This is often due to the combined effects of severe acidosis, dehydration, and renal failure. In a study, 13 out of 17 patients with MALA required invasive mechanical ventilation, and many needed dialysis and vasopressor support.
Conclusion
Metformin-associated lactic acidosis is a rare but serious complication of metformin therapy. The condition is characterized by gastrointestinal symptoms, fatigue, metabolic acidosis, renal dysfunction, and hemodynamic instability. Early recognition and prompt treatment are crucial for improving patient outcomes. Given the high morbidity and mortality associated with MALA, healthcare providers should maintain a high index of suspicion, especially in patients presenting with the aforementioned symptoms and a history of metformin use.
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