Judicious Use of Antibiotics and Antibiotic Resistance

Why "Judicious Use" Matters

Antibiotics are powerful, often life-saving medicines, but their benefit depends heavily on being used correctly. "Judicious use" of antibiotics means taking them only when genuinely needed -- for confirmed or strongly suspected bacterial infections, never for viral illnesses such as the common cold or most cases of flu, against which antibiotics have no effect whatsoever -- and, when prescribed, taking the full course exactly as directed by a doctor, at the correct dose and for the full duration, rather than stopping as soon as symptoms improve.

Why Completing the Full Course Is Important

It is tempting to stop taking an antibiotic once you start feeling better, but doing so is one of the most common and consequential misuses of these drugs. Symptoms typically improve well before every targeted bacterium in the body has actually been killed; the bacteria that are eliminated first tend to be the most susceptible ones, while a smaller number of relatively more resistant bacteria may survive longer. If the antibiotic course is stopped early, these surviving, comparatively resistant bacteria are left alive, free to multiply and potentially cause a relapse of the infection -- one that may now be harder to treat, since the surviving population is enriched for resistance. Completing the full prescribed course ensures the antibiotic has enough sustained exposure to eliminate the bacterial population as completely as possible, minimising the chance that a resistant remnant survives.

What Is Antibiotic Resistance?

Antibiotic resistance is the ability of a bacterium to survive exposure to an antibiotic that would normally kill it or stop its growth. Resistance arises through natural genetic variation and selection: within any large bacterial population, random mutations occasionally produce individual bacteria that happen to carry some trait -- an altered target protein, an enzyme capable of breaking down the antibiotic, a pump that expels the drug from the cell -- that lets them survive exposure to a particular antibiotic. Under normal circumstances, such resistant individuals are rare and offer no particular advantage. But whenever a population of bacteria is exposed to an antibiotic, the susceptible majority is killed off while any resistant individuals survive and are free to multiply, unopposed by competition from their now-eliminated susceptible relatives. Over repeated rounds of antibiotic exposure, this selective pressure can allow resistant strains to become dominant within a bacterial population.

How Overuse and Misuse Accelerate Resistance …