Amoxicillin is the standard first-line antibiotic for most middle ear infections in both children and adults. It works against the most common bacteria responsible for ear infections, has relatively few side effects, and is inexpensive. But the specific antibiotic your doctor chooses depends on the type of ear infection, your age, allergy history, and whether you’ve taken antibiotics recently.
Amoxicillin for Middle Ear Infections
For children, the recommended dose of amoxicillin is high: 80 to 90 mg per kg of body weight per day, split into two doses. This higher dosing helps overcome bacteria that have developed partial resistance to the drug. About 2 in 5 infections caused by the most common ear infection bacterium now show resistance to at least one antibiotic, according to CDC data, which is why standard lower doses are no longer preferred.
For adults, the approach is slightly different. Because middle ear infections are less common in adults and carry a higher risk of complications, doctors typically treat all adult cases with antibiotics rather than waiting to see if symptoms resolve. The preferred first-line choice for adults is actually amoxicillin-clavulanate (the combination sold as Augmentin) at 875 mg twice daily, since adult infections are more likely to involve resistant bacteria.
When Amoxicillin Isn’t Enough
Your doctor will likely skip straight amoxicillin and prescribe amoxicillin-clavulanate in a few specific situations: if you or your child took amoxicillin within the past 30 days, if the ear infection came with pink eye (a pattern called otitis-conjunctivitis syndrome), or if symptoms haven’t improved after 48 to 72 hours on amoxicillin. The clavulanate component helps the amoxicillin work against bacteria that would otherwise break it down.
Children who start on amoxicillin and still have fever, pain, or ear drainage after two to three days should be re-examined. At that point, switching to high-dose amoxicillin-clavulanate is the standard next step.
Options for Penicillin Allergies
If you or your child has a mild or moderate penicillin allergy, several alternatives work well. These include cefdinir, cefuroxime, and cefpodoxime, all taken by mouth. An injectable option, ceftriaxone, can be given as a shot for up to three days when oral antibiotics aren’t practical, such as with a vomiting child.
For severe penicillin allergies (the kind that cause throat swelling or anaphylaxis), the options narrow. Levofloxacin, a fluoroquinolone, can be considered in children with serious allergies when other choices aren’t safe. Your doctor will weigh the risks carefully since fluoroquinolones carry their own side effect profile.
How Long the Antibiotic Course Lasts
Most children under two years old are prescribed a full 10-day course. Older children and adults sometimes receive a shorter 5 to 7-day course. The tradeoff is real: shorter courses cause fewer side effects, particularly digestive issues like diarrhea, but they also carry a higher failure rate. Studies comparing 3 to 5-day courses against 7 to 10-day courses found that shorter treatment led to roughly 57% more treatment failures at one month. For amoxicillin-clavulanate specifically, the failure rate was 82% higher with 5 days compared to 10.
This doesn’t mean a shorter course never makes sense. For children two and older with mild, one-sided infections, a shorter course may be appropriate. Your doctor will factor in age, severity, and history of recurrent infections.
What to Expect After Starting Treatment
Most children start feeling noticeably better within two to three days of starting antibiotics. Fever typically breaks within 48 hours. Ear pain should start improving by the second day and resolve by the third. If pain and fever persist beyond 72 hours, that’s a clear signal the current antibiotic isn’t working and a follow-up visit is needed.
Even after symptoms disappear, finishing the full prescribed course matters. Stopping early increases the chance of the infection returning, potentially with bacteria that are harder to treat the second time around.
When Antibiotics May Not Be Needed
Not every ear infection requires antibiotics right away. Many mild cases, especially in older children, resolve on their own. The CDC outlines specific criteria for a “watchful waiting” approach:
- Children 6 to 23 months old: observation is reasonable if only one ear is infected, pain is mild, temperature is below 102.2°F, and symptoms have lasted less than two days.
- Children 2 years and older: observation can be appropriate even with both ears infected, as long as pain is mild, fever is below 102.2°F, and symptoms are recent.
Watchful waiting means managing pain with over-the-counter pain relievers and rechecking within 48 to 72 hours. If symptoms worsen or don’t improve, antibiotics are started at that point. This approach helps avoid unnecessary antibiotic use, which contributes to growing resistance.
Adults are generally treated with antibiotics right away. Because ear infections are uncommon in adults, the limited research on safely withholding treatment means most doctors err on the side of prescribing.
Antibiotic Drops for Outer Ear Infections
Outer ear infections (swimmer’s ear) are a completely different condition from middle ear infections, and they’re treated with antibiotic ear drops rather than oral antibiotics. The infection sits in the ear canal rather than behind the eardrum, so topical treatment delivers medication directly where it’s needed.
The most commonly prescribed drops contain ciprofloxacin, often combined with a steroid like dexamethasone to reduce swelling and pain. Gentamicin drops are another option, particularly for infections caused by certain gram-negative bacteria. These drops are applied directly into the ear canal, typically for 7 to 10 days. Oral antibiotics are only added for outer ear infections if the infection has spread beyond the ear canal or if the patient has a weakened immune system.
Risks of Leaving an Infection Untreated
Most mild ear infections that go untreated will clear on their own, but bacterial infections that persist can spread. The most concerning complication is mastoiditis, an infection of the bone directly behind the ear. This happens when a middle ear infection spreads into the surrounding bone and can lead to serious problems including partial or complete hearing loss, facial paralysis, inner ear infection, and in rare cases, meningitis or sepsis. Mastoiditis typically requires hospitalization and sometimes surgery, which is why ear infections that aren’t improving deserve prompt medical attention.