P-29 Metformin poisoning without lactic acidosis: Case report

Abstract

Abstract Introduction Metformin is the most widely used oral antidiabetic, which belongs to the biguanide pharmacological group. Metformin-associated lactic acidosis (MALA) is a rare event with an incidence of approximately 19 cases per 100,000 patient-years. The risk of developing lactic acidosis, when taking metformin is enhanced by several factors such as: age > 65 years; concomitant diseases that have the ability to induce hypoxemia (chronic renal failure, congestive heart failure, cardiogenic shock, severe lung disease, sepsis, advanced liver disease, history of lactic acidosis); an excessive alcohol consumption; an administration of iodinated contrast agents. Clinical Case A 46-year-old man was urgently admitted with the following symptoms: drowsiness, repeated vomiting, lethargy, dizziness. The symptoms started after he administered outpatient and at own initiative 50 tablets of metformin, each tablet contains a dose of 500 mg (total dose 25g). Concomitant pathologies: diagnosed with Type 2 Diabetes for 8 years; Toxic liver cirrhosis, compensated Child-Pugh A (recently diagnosed); hypertension; CKD G3aA2 KDIGO. The patient's condition at admission was assessed as extremely serious, Glasgow scale - 11 points, mild hypertension, tachycardia, tachypnea. The paraclinical investigations revealed the presence of metabolic acidosis, but with lactate <5 mmol/l; the progressive renal dysfunction with creatinine values in the first 24 hours up to 1184 µmol/l, urea – 24.5 mmol/l; a severe hypoglycemia - 1.68 mmol/l; a moderate cytolytic syndrome; a cholestatic syndrome, an inflammatory and hepatoprive syndrome; coagulation disorders; a pancreatic dysfunction. In the context of the evident increase of urea and creatinine, the decision was made to initiate the intermittent hemodialysis, a total of 14 sessions were required during hospitalization. The particularity of this case is represented by the absence of lactic acidosis, despite metformin intoxication with altered neurological status, acute renal failure, developed due to chronic kidney disease, liver cirrhosis of toxic etiology and severe hypoglycemia. Conclusion Metformin should be administered with caution in patients with multiple comorbidities. Metformin intoxication can induce lactic acidosis with an increased risk of serious, potentially fatal adverse events. It is essential to identify metformin intoxication as early as possible, with prompt initiation of renal replacement measures and dynamic monitoring of biochemical parameters.