Title: Observation for the development of metformin associated lactic acidosis after an acute metformin overdose<br/>Author: Hong Kim<br/><a href='http://umem.org/profiles/faculty/526/'>[Click to email author]</a><hr/><p>
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Metformin is one of the most commonly prescribed oral hypoglycemic agents. Metformin associated lactic acidosis (MALA) is uncommon but potentially life-threatening complication of metformin overdose. </p>
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Lactic acidosis occurs due to inhibition of mitochondrial glycerophosphate dehydrogenase, resulting in decreased conversion of lactic acid to pyruvate.</p>
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A small retrospective study (using Illinois Poison Center data) attempted to characterize the development of MALA after an acute overdose.</p>
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<strong>MALA was defined as </strong></p>
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Lactate: > 5 mmol/L</li>
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Acidemia: (HCO<sub>3</sub>< 20 mmol/L or pH < 7.35)</li>
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<strong>Results</strong></p>
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40 cases of MALA identified between Jan. 2001 to Dec. 2014</p>
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Meadian age: 41 year</li>
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Female: 55%</li>
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Acute on chronic ingestion: 62.5%</li>
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Hypoglycemia: 3 (7.5%)</li>
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Time to development of MALA (n=30)</p>
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<=6 hours: 18 (60%)</li>
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6-12 hours: 9 (30%)</li>
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>12 hours: 3 (10%)</li>
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Unknown: 10</li>
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Death: 1 (2.5%)</p>
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<strong>Conclusion</strong></p>
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The majority of MALA developed within 6 hours. However, delayed onset of MALA can occur, up to 12 hours post ingestion.</li>
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Minimum of 12 hour of observation is recommended after an acute metformin overdose.</li>
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<fieldset><legend>References</legend>
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<span style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-size: 16px; font-family: Calibri, Helvetica, sans-serif;">Jillian Theobald, Jamie Schneider, Navneet Cheema & Carol DesLauriers (2019) "Time to development of metformin-associated lactic acidosis," Clinical Toxicology, DOI: 10.1080/15563650.2019.1686514</span></p>
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