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Using antibiotics wisely
Audience: patients-public, students-learners ยท Review state: published
What antibiotics do and do not do
Antibiotics are medicines that kill bacteria or stop them from multiplying. They are one of the most important groups of medicines ever developed, and they have turned many once-deadly infections into treatable ones.
Antibiotics work only against bacteria. They do nothing against viruses, which cause colds, most sore throats, flu, and most chest infections. Taking an antibiotic for a viral illness does not speed recovery, does not prevent others from catching the virus, and still exposes the person to side effects.
Different antibiotics work against different bacteria. The choice of drug, dose, and length of treatment depends on the infection, its severity, and sometimes on laboratory testing that identifies the specific bacterium and which drugs can kill it.
Why antibiotic resistance matters
Bacteria evolve. When bacteria are exposed to an antibiotic, the most susceptible ones die first, and any that happen to carry resistance traits survive and multiply. Over time and across many exposures, resistant strains become more common.
This is antibiotic resistance: infections that were once easy to cure become harder, sometimes impossible, to treat with available drugs. Resistance is driven mainly by antibiotic use - every course creates selective pressure - and especially by unnecessary use, wrong drug choice, and incomplete courses.
Resistance is a shared problem. Resistant bacteria spread between people, in hospitals, in communities, through food, and across borders. How antibiotics are used by each person affects how well they work for everyone else in the future.
Using them well
Antibiotics should be taken only when a clinician judges that a bacterial infection is likely, and then exactly as prescribed: the right dose, at the right times, for the full course. Stopping early because symptoms improve can leave the hardiest bacteria alive.
Some uses are never appropriate: taking leftovers from an earlier illness, using antibiotics prescribed for someone else, or pressuring a clinician for antibiotics for a viral illness. Good self-care for viral infections - rest, fluids, and symptom relief - is usually all that is needed while the immune system clears the virus.
Preventing infections in the first place reduces the need for antibiotics at all: vaccination, hand washing, safe food handling, and other basic measures all lower the burden of infection and, with it, the selective pressure that breeds resistance.
Common questions
Feeling better quickly after starting an antibiotic is common, but the course should still be finished as prescribed. If side effects occur - rash, severe diarrhea, or signs of an allergic reaction - medical advice should be sought promptly rather than simply stopping.
Missing a dose is usually handled by taking it when remembered, unless it is nearly time for the next one; doubling up is generally not advised. The instructions that come with the specific medicine and the prescriber's advice take precedence over general guidance.
Antibiotics are powerful and generally safe when used correctly, but they can interact with other medicines and are unsuitable for some people. A clinician or pharmacist should know about other medicines, allergies, pregnancy, and long-term conditions before an antibiotic is started.
Limitations
General educational overview, not medical advice and not guidance on any specific antibiotic, infection, or person. Whether an antibiotic is needed, which one, and for how long are decisions for the treating clinician, who has the examination findings, test results, and local resistance patterns this article does not.