Antibiotic-Resistant Bacteria Induced by Your Family Doctor?

Your doctor may prescribe an antibiotic for a urinary tract or respiratory infection, and you recover and forget all about it.  But it seems that there may be a long-lasting hangover from a short course of treatment – some antibiotic resistant organisms.  This is according to a report in the British Medical Journal.   

University of Bristol researchers in the UK analyzed data from 24 studies that looked for an association between antibiotic use in family practice and subsequent resistance in individual patients.  In 5 of the studies, which included 14,000 patients treated for urinary infections, the odds of an individual patient having a resistant pathological organism two months later was 2.5-times that of a person who wasn’t given the antibiotic; at 12 months, there was still a slight risk – 1.33-times increased odds.

Seven of the studies involving 2600 patients with respiratory infections treated with an antibiotic.  The odds of having resistant bacteria 2 and 12 months after the antibiotic were 2.4-times that of someone who didn’t receive an antibiotic - for both periods.  Across the total range of studies there was evidence for a dose-response for development of resistance with two antibiotics commonly prescribed, amoxicillin and trimethoprim. 

The authors of the study point out that resistance is not confined to the original pathogenic organism, but can be transferred from invading bacteria to ‘commensal’ organisms, i.e. natural bacteria that live on and in a healthy person.  This makes their final recommendation particularly important: “The fewest number of antibiotics should be prescribed for the shortest period possible."