Antibiotics for common infections
Which antibiotics US clinical guidelines recommend for each common infection — the first-line options, penicillin-allergy alternatives, and, just as important, when an infection usually doesn’t need antibiotics at all. Prescription-only; not medical advice.
- Urinary tract infection (UTI)3 first-line →
A bladder UTI (cystitis) is a bacterial infection that usually needs a short course of antibiotics. The best choice depends on local resistance and your history; a clinician typically prescribes one of the first-line agents below.
- Strep throat (streptococcal pharyngitis)2 first-line →
Strep throat is a bacterial infection (group A strep) confirmed by a rapid test or culture — a sore throat alone is often viral and doesn't need antibiotics. When strep is confirmed, penicillin-class antibiotics are first-line.
- Sinus infection (sinusitis)2 first-line →
Most sinus infections are viral and get better on their own — antibiotics only help the minority that are bacterial (typically symptoms lasting 10+ days without improvement, or that worsen after initial improvement). Watchful waiting is a reasonable first step.
- Ear infection (acute otitis media)2 first-line →
Many ear infections improve on their own, so guidelines support a watchful-waiting option with pain control for some children. When an antibiotic is used, amoxicillin is first-line for most.
- Tooth infection (dental abscess)2 first-line →
The real fix for a dental abscess is dental treatment — drainage or a root canal/extraction — not antibiotics. The ADA guideline reserves antibiotics for when definitive dental care isn't immediately available or there's spreading/systemic infection.
- Bacterial pink eye (bacterial conjunctivitis)3 first-line →
Pink eye is often viral or allergic and doesn't need antibiotics. Bacterial conjunctivitis is frequently self-limited too, but antibiotic eye drops can shorten it and are commonly prescribed — especially with thick discharge.
- Acute bronchitis (chest cold)usually none →
Acute bronchitis is almost always viral — and the honest answer is that antibiotics usually do NOT help and can cause harm. Guidelines from the CDC and American College of Physicians recommend against routine antibiotics.
General reference, not medical advice. Antibiotics are prescription-only; overuse drives resistance. The right treatment depends on the specific infection, local resistance, and your history — see a licensed clinician.