Antibiotics: When They Work, When They Don't, and Why It Matters

Antibiotics only treat bacterial infections. They are useless against viruses (colds, flu, most sore throats, bronchitis, COVID-19, RSV).

When Antibiotics Work

• Strep throat (GAS)
• Bacterial pneumonia
• UTIs (most)
• Skin infections (cellulitis, abscesses)
• Sepsis, meningitis, bacterial STIs

When They Don't

• Viral URIs (cold, flu, COVID)
• Viral bronchitis/bronchiolitis
• Most sinusitis (viral >10 days before bacterial considered)
• Most sore throats (viral)

Risks of Misuse

• Resistance: Surviving bacteria pass resistance genes—global crisis.
• Microbiome Disruption: C. diff colitis, yeast infections, long-term metabolic/immune effects.
• Side Effects: GI upset, allergy, drug interactions, QT prolongation (macrolides/fluoroquinolones).
• False Security: Delays correct diagnosis/treatment.

Right Approach

Clinician diagnosis → targeted antibiotic if bacterial → narrow spectrum, shortest effective duration. Patient: don't demand; don't save leftovers; don't share.