Amoxicillin is the best first-line antibiotic for a middle ear infection, the most common type. It’s effective, inexpensive, and well-tolerated, which is why the CDC and the American Academy of Pediatrics both recommend it as the go-to choice. But “best” depends on the type of ear infection you’re dealing with, whether you’ve taken antibiotics recently, and in some cases, whether you need antibiotics at all.
Middle Ear Infections: Amoxicillin First
A middle ear infection (acute otitis media) is the kind most people picture: fluid and pressure behind the eardrum, often following a cold. It’s extremely common in children but happens in adults too. Amoxicillin remains first-line therapy for anyone who hasn’t taken it within the past 30 days. It works well against the bacteria most likely to cause these infections, and it causes fewer side effects than broader-spectrum alternatives.
If you or your child took amoxicillin within the last 30 days, a combination version called amoxicillin-clavulanate is typically recommended instead. The added ingredient helps overcome bacteria that may have developed resistance to plain amoxicillin. This combination is also preferred when a child has pink eye alongside the ear infection or a history of recurring ear infections that didn’t respond to amoxicillin alone.
Some Ear Infections Don’t Need Antibiotics
Not every middle ear infection requires an antibiotic right away. For children six months and older with a single-ear infection and no severe symptoms, a “watch and wait” approach is a legitimate option. For kids two and older, observation without antibiotics is also reasonable even with a bilateral (both ears) infection, as long as symptoms aren’t severe. The key condition: there needs to be a plan to follow up within 48 to 72 hours if things aren’t improving.
Severe symptoms change the calculus. If a child looks very ill, has ear pain lasting more than 48 hours, or has had a fever of 102.2°F or higher in the past two days, antibiotics should start right away. The same applies when reliable follow-up can’t be guaranteed.
How Long the Course Lasts
The length of antibiotic treatment depends on age and severity. Children under two years old are prescribed a 10-day course regardless of how severe the infection appears. The same goes for severe infections at any age, or for children with underlying medical conditions, craniofacial differences, or a perforated eardrum. Kids two and older with a mild to moderate infection typically need only a 5-day course. Adults generally follow a similar 5-to-10 day range based on severity.
What Happens if Amoxicillin Doesn’t Work
Amoxicillin failure is defined as symptoms like ear pain, irritability, poor sleep, or fever that persist after at least 48 to 72 hours of treatment, combined with continued signs of infection on exam. This doesn’t mean the antibiotic was the wrong choice initially. It means the specific bacteria involved may need something stronger.
The next step is usually switching to amoxicillin-clavulanate at a higher dose. If that also fails, a short course of an injectable antibiotic (ceftriaxone, given as a shot over three days) is the typical backup. These escalations are uncommon, but they’re well-established in guidelines so your doctor will have a clear plan if the first round doesn’t resolve things.
Outer Ear Infections Are Treated Differently
Swimmer’s ear (otitis externa) is an infection of the ear canal rather than behind the eardrum, and it calls for a completely different approach. The first-line treatment is antibiotic ear drops, not oral antibiotics. No single drop formulation has been shown to be clinically superior to another. The choice comes down to cost, how often you need to use them daily, and whether the eardrum is intact.
Common options include:
- Ciprofloxacin-dexamethasone drops: Used twice daily. Safe even if the eardrum is perforated.
- Ofloxacin drops: Used once or twice daily. Also safe with a perforated eardrum.
- Ciprofloxacin-hydrocortisone drops: Used twice daily.
- Neomycin-polymyxin-hydrocortisone drops: Used three to four times daily. Should not be used if there’s any chance the eardrum has a hole in it, as the ingredients can damage hearing.
- Acetic acid drops: Used four to six times daily. The least expensive option and effective for mild cases.
Regardless of which drops are used, 65% to 90% of patients see their symptoms resolve within seven to ten days. The steroid component in most of these formulations helps reduce swelling and pain alongside the antibiotic.
One important safety note: if there’s a perforation or suspected perforation of the eardrum, certain drops containing aminoglycosides or alcohol should be avoided because they can be toxic to the inner ear. Quinolone-based drops (the ciprofloxacin and ofloxacin formulations) are the only topical agents FDA-approved for use when the eardrum isn’t intact.
Choosing Between Oral and Topical Antibiotics
The distinction matters because the wrong type of treatment won’t help much. A middle ear infection sits behind the eardrum where drops can’t reach, so it requires oral antibiotics (or in some cases, watchful waiting). An outer ear infection sits in the canal where drops work directly on the infected tissue, making them far more effective than pills for that location. If you’re unsure which type you’re dealing with, the key difference in symptoms is that outer ear infections cause pain when you tug on the outer ear or press on the small flap in front of the ear canal, while middle ear infections typically don’t.