Using antibiotics safely: what everyone should know

Antibiotics treat bacteria, not viruses

Antibiotics work against bacteria. They do nothing against viruses, which cause most coughs, colds, sore throats, sinus problems and flu. This is why a doctor may not prescribe an antibiotic for these — it would not help, and would expose you to side effects for no benefit. Many everyday infections settle on their own with rest, fluids and simple remedies. When an antibiotic is prescribed, it is because a bacterial infection is likely or confirmed, such as some chest, urine, skin or dental infections. If you are unsure whether your illness is viral or bacterial, your pharmacist or GP can advise — but pressing for an antibiotic "just in case" is rarely the right answer.

Antibiotic resistance and stewardship

Every time antibiotics are used, bacteria get a chance to adapt and become resistant — meaning the medicine no longer kills them. This is antimicrobial resistance, and it is one of the biggest threats to modern medicine: routine operations and infections become harder to treat. "Antibiotic stewardship" simply means using these medicines only when genuinely needed, choosing the right one, and taking it exactly as advised. You play a part too: do not take antibiotics left over from before, do not share them, and do not request them for viral illnesses. Protecting antibiotics now keeps them working when you, or someone you love, really needs them later.

Take and finish as advised

Take antibiotics exactly as instructed — at even intervals through the day and, where directed, with or without food, since some are absorbed better one way. Complete the course your prescriber recommends rather than stopping the moment you feel better; advice on length is increasingly tailored, so follow what you are told for your infection. If you forget a dose, take it when you remember unless it is nearly time for the next one — never double up. If symptoms worsen, fail to improve, or you feel much more unwell, seek advice rather than simply continuing, as the chosen antibiotic may not be the right one or further assessment may be needed.

Allergies, side effects and interactions

Tell any prescriber if you have had a reaction to penicillins such as amoxicillin — a true penicillin allergy can cause rash, swelling or breathing difficulty and means alternatives are needed. Common, usually mild side effects include diarrhoea, feeling sick and thrush, because antibiotics disturb the body's normal bacteria. Occasionally this allows a gut infection called Clostridioides difficile (C. diff) to flourish, causing severe, watery diarrhoea that needs urgent attention. Doxycycline and other tetracyclines can make skin burn more easily in sunlight (photosensitivity), so use sun protection. Macrolides such as clarithromycin can interact with statins and with warfarin, among others, so always share your full medicine list. Report any severe rash, swelling or breathlessness immediately.