Title: Frequency of adverse effects after administration of physostigmine<br/>Author: Hong Kim<br/><a href='http://umem.org/profiles/faculty/526/'>[Click to email author]</a><hr/><p>
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Physostigmine is a cholinergic agent that can be administered to reverse delirium associated with anticholinergic toxicity. However, it is infrequenly used since the reports of cardiac arrest in patients with TCA overdose.</p>
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A recently published study reviewed 161 articles – involving 2299 patients – to determine the adverse effects and their frequency after the administration of physostigmine. </p>
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Findings</p>
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Adverse effects were observed in 415 patients (18.1%)</p>
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In patients with anticholinergic overdose: 7.7%</li>
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In patients with non-anticholinergic agent overdose: 20.6%</li>
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Specific adverse effects</p>
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Hypersalivation: 206 (9%) </li>
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Nausea/vomiting: 96 (4.2%)</li>
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Seizure: 14 (0.61%)</li>
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Symptomatic bradycardia: 8 (0.35%) – including 3 with bradyasystolic arrest</li>
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Asymptomatic bradycardia: 4 (0.17%)</li>
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Ventricular fibrillation: 1 (0.04%) patient had a history of coronary artery disease</li>
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Cardiac arrest: 4 (0.17%)</li>
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Death: 5 (0.22%)</li>
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Of 394 TCA overdose, adverse effects occurred in 14 patients (3.6%)</p>
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<strong>Conclusion</strong></p>
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Adverse effects from physostigmine occurs infrequently. </li>
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However, inappropriate dosing or use of physostigmine can result in cholinergic toxicity.</li>
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For isolated anticholinergic toxicity (e.g. antihistamine overdose): physostigmine dosing: 0.5 mg (dilute in 5 – 10 mL normal saline) IV over 2 -5 minutes. May repeat every 5-10 minute to max dose total of 2 mg. (patient needs to be on cardiac monitor with atropine at bedside) </li>
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Therapeutic goal: reversal of delirium</li>
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Avoid physostigmine in the presence of QRS widening (cardiac Na-channel blockade) and patients with history of underlying coronary artery disease.</li>
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<fieldset><legend>References</legend>
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Arens AM et al. Adverse effects of physostigmine. J Med Toxciol. <span style="font-family: arial, helvetica, clean, sans-serif; font-size: 11.99899959564209px;"> Feb 11. doi: 10.1007/s13181-019-00697-z. [Epub ahead of print] Review.</span></p>
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