Lactic acidosis secondary to metformin toxicity :a case report

Haddad Hemmat El; Manal Abufarha; Nermine Zawilla; Ahmed Fayed; Mohamed Magdy; Randa Salam; Mohamed Mahmoud; Noha Tarek; Salma Mohamed; Tasneem Halaby; Sara Asal; Ahmed Atef; Alla Abdallah; Ayat Magdi

doi:10.1530/endoabs.110.EP984

JOINT237

Introduction: Metformin is an oral antidiabetic drug in the biguanide class. It is the first-line drug of choice for the treatment of type 2 diabetes. The most common symptoms following overdose appear to include vomiting, diarrhea, abdominal pain, tachycardia, drowsiness, and, rarely, hypoglycemia. The major potentially life-threatening complication of Metformin overdose is metabolic acidosis. We report a case of fatal Metformin toxicity following an acute intentional Metformin intoxication.

Case report: 18 years old female presented to the emergency department three hours after a suicide attempt with 30 grams of metformin, severely agitated, confused. With severe abdominal pain associated with persistent vomiting Examination Pulse: 120/minute, BP: 80/60mmHg, Temprature was 37.0°C. and respiratory rate of 28. cardio-respiratory system was normal; her abdomen was soft and non-tender. Arterial blood gas analysis on admission showed a profound lactic acidosis:pH 6.8 (7.38 to 7.42); pCO2 :27 (35-45Mmhg), pO2:99 bicarbonate 4.2 (22-28 mmol/L)and lactate >15 (<1 mmol/l)Blood test results at presentation HB: 11.2g, platelet 131 (150-450) Creatinine 1.8mg (0.74 to 1.35) family members took her to toxicology emergency unit where gastric lavage was done, oral charcoal and intravenous fluids were given. During her ICU stay Day 1 The patient had severe lactic acidosis, for which she received sodium bicarbonate (200 ml) infusion. She was resuscitated by intra-venous fluids (Ringer acetate) and put on noradrenaline with no response so adrenaline was added Day 2 Lactic acidosis was persistent and severe so she received one hemodialysis session after nephrology consultation. Day 3 The patient was off adrenaline but withdrawl of nor-adrenaline failed so dobutamine infusion was added supported by the data detected in echocardiography EF 20%, akinetic whole septum, hypokinetic other whole segments sparing apical segments (apical segments contract better than basal segments). Day 4 The patient developed one attack of convulsions generalized tonic seizures followed by post-ictal confusion. Neurology consultation revealed unremarkable MRI with diffusion and EEG levetiracetam 500 was given twice daily Day 5 The patient was off nor-adrenaline then off dobutamine with intact peripheral pulsations and normal blood pressure echocardiography was normal. EF 60%.

Conclusions: metformin overdose, diagnosis and timely intervention in the form of hemodialysis for metabolic acidosis, coupled with sufficient hemodynamic resuscitation. Hence, emergency clinicians and toxicologists must maintain a high level of suspicion for drug poisoning in any patient presenting with marked metabolic acidosis or displaying symptoms related to the gastrointestinal and respiratory systems.

Endocrine Abstracts

EP984