Podcast 530: Anion Gap Acidosis + Metformin Toxicity

<p><strong>Contributor: Don Stader, MD</strong></p> <p><strong>Educational Pearls:</strong></p> <ul> <li style="font-weight: 400;"><span style="font-weight: 400;">The common causes of anion gap metabolic acidosis include (MUDPILES)</span></li> <li style="list-style: none; display: inline"> <ul> <li style="font-weight: 400;"><span style= "font-weight: 400;">Metformin, Methanol </span></li> <li style="font-weight: 400;"><span style= "font-weight: 400;">Uremia </span></li> <li style="font-weight: 400;"><span style= "font-weight: 400;">DKA</span></li> <li style="font-weight: 400;"><span style= "font-weight: 400;">Paraldehyde </span></li> <li style="font-weight: 400;"><span style= "font-weight: 400;">INH/Iron </span></li> <li style="font-weight: 400;"><span style= "font-weight: 400;">Lactate</span></li> <li style="font-weight: 400;"><span style= "font-weight: 400;">Ethylene Glycol </span></li> <li style="font-weight: 400;"><span style= "font-weight: 400;">Salicylate </span></li> </ul> </li> <li style="font-weight: 400;"><span style= "font-weight: 400;">Metformin is a very common drug used to treat type 2 diabetes, however in the right setting, it can cause a profound lactic acidosis. There is a very high mortality rate. </span></li> <li style="font-weight: 400;"><span style= "font-weight: 400;">Treatment of metformin toxicity includes fluids, bicarb, and dialysis </span></li> <li style="font-weight: 400;"><span style="font-weight: 400;">Most commonly, metformin toxicity is in the setting of kidney injury or overdose. </span></li> <li style="font-weight: 400;"><span style= "font-weight: 400;">Always consider acidosis in those with tachypnea! </span></li> </ul> <p><strong>References</strong></p> <p><span style="font-weight: 400;">Re-evaluation of a biguanide, metformin: mechanism of action and tolerability. Sirtori CR, Pasik C Pharmacol Res. 1994;30(3):187. </span></p> <p><span style="font-weight: 400;">Bicarbonate haemodialysis as a treatment of metformin overdose.Heaney D, Majid A, Junor B. Nephrol Dial Transplant. 19