Antibiotics treat certain bacterial infections and do not treat viral infections such as colds. A qualified prescriber should decide when they are needed. Do not use this overview to select an antibiotic or dose. Do not take leftover antibiotics, use another person’s supply or share a prescription. Ask what the medicine is for and follow the individual instructions. Contact the treating team about problems rather than selecting a different dose or duration from a chatbot. Check other medicines and allergies with a professional. This article cannot choose an antibiotic for fever, cough or suspected infection.