One of the most well-known concepts in medicine, to both doctors and patients, is that you must absolutely finish a course of antibiotics. The thinking goes that if you don’t eradicate every last bacterium causing your illness, the survivors can develop resistance and wreak further havoc.
This concern was voiced by the venerated Alexander Fleming himself — discoverer of penicillin, the first true antibiotic — which is part of why the idea is so enduring. Toward the end of his 1945 Nobel Prize acceptance speech, Fleming warned that “there is the danger that the ignorant man may easily underdose himself and by exposing his microbes to nonlethal quantities of the drug make them resistant.”
This proclamation is only half true. If humanity truly wants to slow the spread of antibiotic resistance, we need to also look at the overprescription of antibiotics.
Recently, a group of British health professionals penned a compelling analysis in The BMJ, advocating for shorter antibiotics courses — even going so far as to say that maybe patients should stop taking antibiotics once they feel better.
As the list of antibiotic resistant bacteria grows, so have the extraordinary efforts to prevent the spread of infection. Science correspondent Miles O’Brien and economics correspondent Paul Solman team up for a report.
That’s because Fleming only described one version of resistance: Where bad bugs get worse by surviving an “underdosing” of antibiotics. Researchers call that “target selection.”
But there’s a flip side: Overusing antibiotics can cause usually nice bugs, with which we coexist, to gain resistance. The germs jump at the opportunity to take over ecological niches, like the gut of a patient on antibiotics. This form of resistance is called “collateral selection.”
The BMJ analysis, led by infectious disease specialist Martin Llewelyn, proposes that “most of the bacterial species now posing the greatest problems do not develop resistance through target selection” and that “collateral selection is the predominant driver of the important forms of antibiotic resistance affecting patients today.”
In other words, overdosing…