{"id":1133,"date":"2010-10-22T11:40:58","date_gmt":"2010-10-22T15:40:58","guid":{"rendered":"http:\/\/blogs.nejm.org\/?p=1133"},"modified":"2026-01-17T05:37:46","modified_gmt":"2026-01-17T10:37:46","slug":"how-to-figure-out-the-length-of-antibiotic-therapy","status":"publish","type":"post","link":"https:\/\/blogs.nejm.org\/hiv-id-observations\/index.php\/how-to-figure-out-the-length-of-antibiotic-therapy\/2010\/10\/22\/","title":{"rendered":"How to Figure Out the Length of Antibiotic Therapy"},"content":{"rendered":"<p><img loading=\"lazy\" decoding=\"async\" class=\"alignright size-full wp-image-1134\" title=\"keys to the kingdom\" src=\"http:\/\/blogs.nejm.org\/hiv-id-observations\/wp-content\/uploads\/sites\/2\/2010\/10\/keys-to-the-kingdom1.jpg\" alt=\"keys to the kingdom\" width=\"296\" height=\"271\" \/>One thing we ID doctors know &#8212; that other clinicians\u00a0simply don&#8217;t &#8212; is how long to treat a patient with antibiotics.<\/p>\n<p>I was reminded of this special power by these recent events:<\/p>\n<ul>\n<li>An excellent fellow from the hospital&#8217;s Critical Care program rotated through our division recently. When asked about what she wanted learn from the elective, the first thing she said was figuring out &#8212; finally &#8212; how long an antibiotic course should be.<\/li>\n<li>We received a consultation on an unfortunate case that had been hospitalized since approximately the time of the Gerald Ford administration. You know the type &#8212; multiple surgeries gone bad, several GI anastomotic leaks, innumerable tubes and drains, abundant highly-resistant bacteria and yeast cultured from each drain. The question: <em>&#8220;How long should we treat the acinetobacter?&#8221;<\/em><\/li>\n<li>This <a href=\"http:\/\/www.nytimes.com\/2010\/10\/17\/opinion\/17gilbert.html?_r=1&amp;scp=1&amp;sq=numbers+antibiotic&amp;st=nyt\" target=\"_blank\" rel=\"noopener\">great article<\/a> in the New York Times by Harvard &#8220;<a href=\"http:\/\/www.amazon.com\/Stumbling-Happiness-Daniel-Gilbert\/dp\/1400042666\" target=\"_blank\" rel=\"noopener\">Happiness<\/a>&#8221; Professor Daniel Gilbert, who relays being given a 7-day course of antibiotics by a doctor.\u00a0 <em>&#8220;I understood why I needed to complete the full course, of course. What I didn\u2019t understand was why a full course took precisely seven days. Why not six, eight or nine and a half? Did the number seven correspond to some biological fact about the human digestive tract or the life cycle of bacteria?&#8221;<\/em><\/li>\n<\/ul>\n<p>The answer, Dr. Gilbert, is that this is highly-specialized knowledge, rarefied information that only 100% Board-Certified, USDA-inspected Infectious Diseases Doctors know. And since I&#8217;m concerned that your article might give readers the wrong impression about our scientific credibility, I&#8217;ll now divulge what we&#8217;ve learned, and how to apply it.<\/p>\n<p>To figure out how long antibiotics need to be given, use the following\u00a0rules:<\/p>\n<ol>\n<li>Choose a multiple of 5 (fingers of the hand) or 7 (days of the week).<\/li>\n<li>Is it an outpatient problem that is relatively mild? If so, choose something less than 10 days. After application of our multiples rule, this should be 5 or 7 days.<\/li>\n<li>Is it <em>really<\/em> mild, so much so that antibiotics probably aren&#8217;t needed at all but clinician or patient are insistent?\u00a0 Break the 5\/7 rule and go with 3 days. Ditto uncomplicated cystitis in young women.<\/li>\n<li>Is it a serious problem that occurs in the hospital or could end up leading to hospitalization?\u00a0\u00a0With the exception of community-acquired pneumonia (5 or 7 days), 10 days is the minimum.<\/li>\n<li>Patient not doing better at the end of some course of therapy?\u00a0 Extend treatment, again using a multiple of 5 or 7 days.<\/li>\n<li>Does the infection involve a bone or a heart valve? Four weeks (28 days) at least, often 6 weeks (42 days). Note that 5 weeks (35 days) is not an option &#8212; here the 5&#8217;s and 7&#8217;s cancel each other out, and chaos ensues.<\/li>\n<li>The following lengths of therapy are inherently weird, and should generally be avoided:\u00a0 2, 4, 6, 8, 9, 11, 12, 13 days.\u00a0 Also, <a href=\"http:\/\/blogs.nejm.org\/hiv-id-observations\/wp-content\/uploads\/sites\/2\/2010\/10\/math-pi-decimal-matrix.jpg\" target=\"_blank\" rel=\"noopener\">3.14159265<\/a> days.<\/li>\n<\/ol>\n<p>In this highly data-driven exercise, it is important also to note the <em>number<\/em> of rules &#8212; <em>seven<\/em>, as in days of the week.<\/p>\n<p>That did not occur by chance.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>One thing we ID doctors know &#8212; that other clinicians\u00a0simply don&#8217;t &#8212; is how long to treat a patient with antibiotics. I was reminded of this special power by these recent events: An excellent fellow from the hospital&#8217;s Critical Care program rotated through our division recently. When asked about what she wanted learn from the [&hellip;]<\/p>\n","protected":false},"author":6,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5,8],"tags":[72,498],"class_list":["post-1133","post","type-post","status-publish","format-standard","hentry","category-infectious-diseases","category-patient-care","tag-antibiotics","tag-infectious-diseases"],"post_mailing_queue_ids":[],"_links":{"self":[{"href":"https:\/\/blogs.nejm.org\/hiv-id-observations\/index.php\/wp-json\/wp\/v2\/posts\/1133","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blogs.nejm.org\/hiv-id-observations\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blogs.nejm.org\/hiv-id-observations\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.nejm.org\/hiv-id-observations\/index.php\/wp-json\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.nejm.org\/hiv-id-observations\/index.php\/wp-json\/wp\/v2\/comments?post=1133"}],"version-history":[{"count":0,"href":"https:\/\/blogs.nejm.org\/hiv-id-observations\/index.php\/wp-json\/wp\/v2\/posts\/1133\/revisions"}],"wp:attachment":[{"href":"https:\/\/blogs.nejm.org\/hiv-id-observations\/index.php\/wp-json\/wp\/v2\/media?parent=1133"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.nejm.org\/hiv-id-observations\/index.php\/wp-json\/wp\/v2\/categories?post=1133"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.nejm.org\/hiv-id-observations\/index.php\/wp-json\/wp\/v2\/tags?post=1133"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}