All medical professionals have likely dealt with the aftermath of the media’s picking up a provocative article or concept and popularizing it, often with an unintended change in the original message. Usually I cringe when I hear these, knowing that I will be facing questions about the mixed message that was sent. After all, how many times have we almost cured cancer? However, this time, I was happy to see a focus on the undetermined importance of fixed antibiotic durations, commonly presented under the guise of “maybe you can stop antibiotics when you feel better” or something similar.
This wave of consumer stories was stimulated by an interesting hybrid review/commentary written in the BMJ
at the end of July 2017 by Llewelyn and colleagues.1
Titled “The Antibiotic Course Has Had Its Day,” the article challenged the notion that completing antibiotic courses after symptom resolution has any benefit. The authors were right to do so. The notion of fixed-duration antibiotic courses is not supported in the literature, something that can probably be discerned by the relationships between antibiotic durations and numbers of convenience. Even more intriguing is the lack of an evidence base for the most common reasons cited for the mantra to “take all your medicine even if you feel better.” Two common rationales for this exist.
The first is that treatment failure is more likely with shorter courses of antibiotics. Although this is true for some chronic infections like tuberculosis, repeated studies of various acute bacterial infections generally show that shorter courses are as effective as more traditional courses of therapy. This has been shown with hospital-acquired and community-acquired pneumonia (CAP), pyelonephritis, pharyngitis, skin and skin structure infections, and intra-abdominal infections.1
Notably, a recent study of otitis media in young children showed higher failure with a short course, though this is a singular study in a non-severe infection.2
Most interesting to me is a study of CAP that compared treatment using daptomycin (which is inactivated by pulmonary surfactant) with ceftriaxone.3
The study found the drugs to be equivalent if patients in the daptomycin group received <24 hours of antibiotics (such as 1 dose of levofloxacin or ceftriaxone) before they were randomized. Because patients taking daptomycin essentially received placebo after they were randomized, the length of time we need to treat patients with CAP needs to be further investigated.