Antibiotics Are Not for Colds and Flu: How to Use Them Right
November 1, 2026 · 3 min read
Antibiotics kill bacteria and do nothing against the viruses behind colds and flu. Using them when they are not needed only adds side effects and helps resistant germs spread.
Plenty of people come to the pharmacy with a bad cold or a cough with green phlegm and ask straight away for antibiotics. That is understandable, because antibiotics used to be handed out for complaints like these. We now know most of them are caused by viruses, and antibiotics do not work against viruses.
Complaints that do not need antibiotics
The U.S. Centers for Disease Control and Prevention (CDC) says antibiotics do not cure:
- colds and runny noses, even when the mucus is thick, yellow or green
- most sore throats, except strep throat
- flu
- most cases of bronchitis
A 2013 Cochrane review also found no benefit from antibiotics for the common cold, in children or adults. What it did find was more side effects.
Side effects people underestimate
Antibiotics can cause rashes, dizziness, nausea, diarrhoea and yeast infections. More seriously, they can lead to a severe gut infection with Clostridioides difficile and to life threatening allergic reactions. The CDC notes that in children, side effects from antibiotics are the most common cause of emergency visits related to medicines.
Germs that resist medicine
Every time antibiotics are used, the toughest bacteria get a chance to survive and multiply. Over time, bacteria appear that no longer respond to treatment. WHO names the misuse and overuse of antimicrobials as what drives drug resistant germs.
The effect is already real. A global analysis in The Lancet estimated that in 2019 bacterial antimicrobial resistance directly caused 1.27 million deaths and was linked to 4.95 million deaths worldwide.
If your doctor prescribes an antibiotic
Antibiotics remain vital for bacterial infections. When a doctor prescribes one:
- take it exactly as written on the prescription, including the times and how many days
- do not keep leftovers for next time
- do not give your antibiotics to anyone else, even if their complaint looks the same
The CDC explains why keeping leftovers is risky: the wrong medicine for the next illness can delay the right treatment.
At Coapotek we only dispense antibiotics with a doctor's prescription. If you are not sure whether a complaint needs a doctor, our pharmacists can help you judge and suggest something to ease cold and flu symptoms.
Sources
- Centers for Disease Control and Prevention. Healthy Habits: Antibiotic Do's and Don'ts.
- Kenealy T, Arroll B. Antibiotics for the common cold and acute purulent rhinitis. Cochrane Database of Systematic Reviews, 2013.
- World Health Organization. Antimicrobial resistance, fact sheet.
- Antimicrobial Resistance Collaborators. Global burden of bacterial antimicrobial resistance in 2019: a systematic analysis. The Lancet, 2022, volume 399, pages 629 to 655.