Think Goldilocks for UTI
Michelle Lin · Emergency Medicine News · 2025
For how many days do you prescribe nitrofurantoin (Macrobid) in uncomplicated UTI? The Goldilocks principle applies: Three days is too short. Seven days is unnecessarily too long. Five days is just right! Do you know about WikiGuidelines? They are an international, not-for-profit collaborative that generates evidence-based guidelines for infectious diseases. They are a little different from other organizations with guidelines because they only provide recommendations if there are high-quality studies available. They don't require experts to come to a consensus and make a recommendation on low-evidence topics. They seem transparent and admit uncertainty if there is not enough evidence. They published guidelines on UTI in JAMA this year. (JAMA Netw Open. 2024;7[11]:e2444495; https://tinyurl.com/yc7nf72w), reporting that there is no evidence that a seven-day course of Macrobid was better than a five-day one. In the era of antibiotic stewardship to minimize antibiotic resistance, five days is the ideal duration with 79%-92% efficacy. On the other spectrum, three days (for which the NICE guidelines still advocate) is too short, with only 61%-70% efficacy. DR. LIN is the founder, CEO, and editor-in-chief of Academic Life in Emergency Medicine (https://www.ALiEM.com) and a professor of emergency medicine at the University of California San Francisco with interests in health professions education and digital scholarship. Follow her on Instagram @MichelleLinMD and on X @M_Lin. Read her past columns at http://tinyurl.com/EMN-Lin. Share this article on X and Facebook. Access the links in EMN by reading this on our website: www.EM-News.com. Comments? Write to us at [email protected].