Title: Cephalosporin Side Chains and Allergies<br/>Author: Ellen Lemkin<br/><a href='http://umem.org/profiles/faculty/182/'>[Click to email author]</a><hr/><p>
When patients with severe allergies to penicillin (urticarial, bronchospasm, anaphylaxis, angioedema) are excluded, the cross reactivity to cephalosporins is <u>very low (approximately 0.1%)</u></p>
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The reaction is related to structures in the<strong> side chain</strong>, not the cyclical structure as thought in the past.</p>
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There are several cephalosporins with <strong>IDENTICAL side chains </strong>that should not be given to patients with allergies to specific penicillins, namely:</p>
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Penicillin: do not give cefoxitin</li>
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Ampicillin: do not give cefaclor or cephalexin</li>
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Amoxicillin: do not give cefadroxil or cefprozil</li>
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<i style="margin: 0px; padding: 0px; color: rgb(0, 0, 0); font-family: Verdana, Arial, Helvetica, sans-serif; line-height: 16px;"><b style="margin: 0px; padding: 0px;">The Medical Letter on Drugs and Therapeutics</b></i><span style="color: rgb(0, 0, 0); font-family: Verdana, Arial, Helvetica, sans-serif; line-height: 16px;"> • December 24, 2012 (</span><a href="http://secure.medicalletter.org/TML-issue-1406" style="margin: 0px; padding: 0px; color: rgb(162, 79, 95); font-family: Verdana, Arial, Helvetica, sans-serif; line-height: 16px;">Issue 1406</a><span style="color: rgb(0, 0, 0); font-family: Verdana, Arial, Helvetica, sans-serif; line-height: 16px;">) p. 101. </span></p>
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