Antibiotic

An antibiotic is a medicine that kills bacteria or inhibits their growth and is used to prevent or treat certain bacterial infections.

Antibiotics act on structures or processes that bacteria need to survive or reproduce. Different antibiotics work against different groups of bacteria, so the appropriate choice depends on factors such as the suspected or confirmed infection, bacterial susceptibility, the site of infection, and the person’s circumstances.

Antibiotics do not treat viral infections such as the common cold or influenza. Unnecessary or inappropriate antibiotic use can contribute to antimicrobial resistance.

QUICK FACT

Antibiotics do not work against viruses. Taking an antibiotic for a viral infection does not make the virus susceptible to the medicine.

COMMONLY CONFUSED WITH

Antimicrobial: Antimicrobial is the broader term. Antibiotics are antimicrobials that act against bacteria.

SEE ALSO

Clinical & Educational Context

Discussed in Health Articles & Guides

Explore how "Antibiotic" is covered across our evidence-based editorial guides:

2 Articles
Unstraight Lines

Kill Me a Little, Kill It More

Antibiotics, for example, can target features of bacteria that human cells do not possess.
The Hard Parts of Medicine

Polypharmacy: What Really Happens When You Take Multiple Medicines

Antibiotics provide a useful example.