Amoxicillin is one of the most prescribed antibiotics in the US, and it turns up after very different visits: a child’s ear check, a sinus appointment, an urgent dental visit. The label and the main US guidelines show where it is a first choice, where it is one option among several, and where no antibiotic helps at all.
Maybe your dentist handed you a prescription for a swollen tooth. Maybe your doctor wrote one for a sinus infection that would not quit, or for a chest infection that turned out to be pneumonia. Either way, you are holding the same small bottle and wondering whether it really fits the problem you have.
The short answer: amoxicillin works against several common bacteria that cause ear, sinus, throat, chest and dental infections. It does nothing against viruses, and for some of these conditions the guidelines say most people do not need an antibiotic in the first place.
The FDA label lists infections of the ear, nose and throat, the lower respiratory tract, the genitourinary tract and the skin caused by susceptible bacteria, plus H. pylori combination therapy in adults. CDC calls amoxicillin first-line for strep throat, children’s ear infections and bacterial sinusitis. The 2019 pneumonia guideline gives it a strong recommendation for healthy adult outpatients. For acute bronchitis and most dental pain, guidelines advise against antibiotics.
Infection by infection: where amoxicillin fits
| Infection | Is amoxicillin used? | What the guidance says | When an antibiotic is usually not needed |
|---|---|---|---|
| Middle ear infection (children) | Yes, first-line | CDC: first-line for children who have not had amoxicillin in the past 30 days | Mild cases may qualify for watchful waiting, depending on age and whether one or both ears are affected |
| Sinus infection | Yes, first-line when bacterial | CDC: amoxicillin or amoxicillin/clavulanate first-line; IDSA 2012 prefers amoxicillin/clavulanate for adults | 90-98% of cases are viral; watchful waiting for uncomplicated cases with reliable follow-up |
| Sore throat (strep) | Yes, first-line | CDC: amoxicillin and penicillin remain first-line for group A strep | Negative rapid strep test; most adult sore throats are not strep |
| Acute bronchitis (chest cold) | No | CDC: routine antibiotic treatment is not recommended, regardless of cough duration | Almost always; the visit focuses on ruling out pneumonia |
| Pneumonia (healthy adult outpatient) | Yes, a leading option | ATS/IDSA 2019: amoxicillin, strong recommendation; doxycycline and, in some areas, a macrolide as alternatives | Not applicable once pneumonia is diagnosed; people with chronic illnesses get different regimens |
| Tooth infection | Sometimes | ADA 2019: amoxicillin or penicillin V potassium when an antibiotic is indicated | Most dental pain and intraoral swelling, when the dentist can treat the tooth itself |
| H. pylori with duodenal ulcer | Yes, in combination | Label: with clarithromycin plus lansoprazole, or with lansoprazole alone | Amoxicillin is not used alone for this |
| Early Lyme disease (rash) | Yes, one option | CDC lists doxycycline, amoxicillin or cefuroxime | Not applicable; treatment is recommended when diagnosed |
The table is a map, not a prescription. The same diagnosis can be handled differently because of age, allergies, recent antibiotic use, pregnancy, local resistance patterns and what the clinician found on examination.
What the label actually approves
The current amoxicillin tablet label on DailyMed groups its uses by body site rather than by diagnosis. It lists infections of the ear, nose and throat; the genitourinary tract; the skin and skin structure; and the lower respiratory tract, each caused by susceptible strains of named bacteria such as Streptococcus species, Streptococcus pneumoniae, Haemophilus influenzae or E. coli. Every one of those lines carries the qualifier “ONLY beta-lactamase-negative” isolates, meaning bacteria that do not make the enzyme that breaks amoxicillin down.
That qualifier explains why some people get amoxicillin/clavulanate (Augmentin) instead. Clavulanate blocks beta-lactamase, so the combination covers more bacteria. When your prescription says plain amoxicillin, the prescriber judged that the likely germs are ones amoxicillin can handle on its own.
The label also tells prescribers to use the drug only for infections “proven or strongly suspected to be caused by bacteria,” and to consider culture results when they exist.
Ear infections
Ear infections in children are where amoxicillin is best known. CDC’s pediatric outpatient guidance says amoxicillin “remains first-line therapy for children who have not received amoxicillin within the past 30 days.”
The same page sets a high bar for the diagnosis. It calls for moderate or severe bulging of the eardrum, or new drainage from the ear that is not due to an outer-ear infection, and it advises against diagnosing a middle ear infection without fluid behind the eardrum. For milder cases, watchful waiting based on shared decision-making may be appropriate, depending on the child’s age and whether one or both ears are involved. So a parent who leaves without a prescription has not been short-changed; the pediatrician may be following that guidance.
Sinus infections
Sinus infections are where amoxicillin is most often handed out for something it cannot fix. CDC’s adult outpatient guidance states that 90-98% of rhinosinusitis cases are viral. It describes bacterial sinusitis as symptoms that are severe for more than 3-4 days (such as fever of 102 F or higher with pus-like nasal discharge or facial pain), persistent for more than 10 days without improvement, or worsening after a cold had started to get better.
When those criteria are met, CDC names amoxicillin or amoxicillin/clavulanate as first-line therapy, doxycycline or a respiratory fluoroquinolone for people with penicillin allergy, and it does not recommend macrolides such as azithromycin because of high pneumococcal resistance. For uncomplicated cases with reliable follow-up, it encourages watchful waiting.
The IDSA 2012 sinusitis guideline goes a step further for adults, recommending amoxicillin/clavulanate rather than amoxicillin alone (a weak recommendation based on low-quality evidence). Our page on sinus infection symptoms and when antibiotics help covers the timeline, and our guide to doxycycline for a sinus infection or pneumonia explains the allergy alternative.
Sore throat and strep
CDC says group A strep causes only 5-10% of adult sore throats. Adults who meet two or more Centor criteria (fever, tonsil exudate, tender neck glands, no cough) should get a rapid strep test, and antibiotics are not recommended when that test is negative. When strep is confirmed, “amoxicillin and penicillin remain first-line therapy.” The label adds that at least 10 days of treatment is recommended for Streptococcus pyogenes infections to prevent acute rheumatic fever; the length of your own course is set by your prescriber.
We cover strep treatment and penicillin allergy labels in detail in Is Amoxil a penicillin?, so we will not repeat it here.
Chest colds and bronchitis
A lingering cough after a cold is the classic case where amoxicillin is requested and not needed. CDC states that “routine treatment of uncomplicated acute bronchitis with antibiotics is not recommended, regardless of cough duration.” The clinician’s job at that visit is to rule out pneumonia, which CDC notes is rare in otherwise healthy adults with normal vital signs.
If you were told you have bronchitis and you were still given amoxicillin, it is fair to ask what the clinician saw that pointed to a bacterial infection.
Pneumonia
Pneumonia is different. The 2019 ATS/IDSA community-acquired pneumonia guideline (Metlay et al., American Journal of Respiratory and Critical Care Medicine, October 2019) lists amoxicillin for healthy outpatient adults without comorbidities as a strong recommendation based on moderate-quality evidence. Doxycycline is a conditional option, and a macrolide is an option only where pneumococcal resistance to macrolides is below 25%.
The panel chose amoxicillin “despite presumed lack of coverage of this antibiotic for atypical organisms,” such as Mycoplasma, citing its track record in pneumonia. For adults with chronic heart, lung, liver or kidney disease, diabetes, alcoholism, cancer or no spleen, the guideline moves to combinations (amoxicillin/clavulanate or a cephalosporin plus a macrolide or doxycycline) or a respiratory fluoroquinolone alone. Plain amoxicillin is therefore mainly a pneumonia drug for otherwise healthy adults treated at home.
Tooth infections
Dental prescriptions surprise people in both directions: some expect an antibiotic and do not get one, others get one without being told why. The American Dental Association’s 2019 guideline (Lockhart et al., JADA, November 2019), summarized in a CDC chairside sheet for dentists, states that antibiotics “are not needed for the urgent management of most dental pain and intraoral swelling” from pulp and root-tip infections in healthy adults. The fix is definitive dental treatment, such as drainage, a root canal or an extraction, plus over-the-counter pain relievers if needed.
The guideline does recommend antibiotics for a dead tooth with a localized abscess when there are systemic signs, such as fever or feeling unwell. If definitive treatment is not immediately available, it also supports antibiotics for a localized abscess without systemic signs, together with urgent referral. When an antibiotic is used, the sheet lists amoxicillin or penicillin V potassium, a follow-up check after 3 days, and a referral for urgent care if the condition worsens, a deep space infection develops or sepsis is suspected.
H. pylori, Lyme disease and other label uses
For adults with H. pylori infection and a current or recent duodenal ulcer, the amoxicillin label lists two combinations: triple therapy with clarithromycin and lansoprazole, and dual therapy with lansoprazole for people who cannot take clarithromycin or whose infection may be resistant to it. Amoxicillin is never the whole treatment here.
For early Lyme disease with the typical expanding rash, CDC’s erythema migrans treatment page lists doxycycline, amoxicillin or cefuroxime as oral options for adults and children, and notes that treatment may need adjusting for age, medical history and pregnancy.
Urinary and skin infections appear on the label as well, but only for susceptible strains, and many urinary isolates are not. A urine culture usually decides whether amoxicillin is a sensible choice.
Get prompt care for signs of a serious allergic reaction; the label warns that serious and occasionally fatal reactions have occurred with penicillins, including oral amoxicillin. Call the prescriber about diarrhea, especially watery or bloody stools, because the label lists C. difficile-associated diarrhea, from mild to fatal colitis. For a dental infection, the ADA guidance calls for urgent referral if swelling worsens, a deep space infection develops or sepsis is suspected. If you are not improving on schedule, our guide on when amoxicillin should start working explains when to recheck the diagnosis.
What amoxicillin cannot treat
The label is blunt: antibacterial drugs, including amoxicillin, “do not treat viral infections (e.g., the common cold).” That rules out colds, flu, most sore throats, most sinus congestion in the first week and nearly all acute bronchitis. CDC’s pediatric guidance says the same for children: for the common cold and nonspecific upper respiratory infections, “do not prescribe antibiotics.”
It also cannot reach bacteria that produce beta-lactamase without the help of clavulanate, and it does not cover the atypical germs that sometimes cause pneumonia, which is why combinations and alternatives exist. One more specific limit: the label says a high percentage of people with infectious mononucleosis who receive amoxicillin develop a rash, and that it should not be given to people with mono. A sore throat that turns out to be mono is one reason a clinician may test before prescribing.
If the bottle in your hand does not seem to match what you were told, ask two questions at the pharmacy or the next visit: what infection is this treating, and what would make the prescriber change course? Those answers tell you more than any general list.
Sources
- DailyMed: Amoxicillin tablets label
- CDC: Outpatient clinical care for adults
- CDC: Outpatient clinical care for pediatric populations
- Chow et al., IDSA guideline for acute bacterial rhinosinusitis, Clin Infect Dis 2012
- Metlay et al., ATS/IDSA community-acquired pneumonia guideline, 2019
- CDC: Dentists, treating patients with dental pain and swelling (ADA 2019 guideline summary)
- CDC: Clinical treatment of erythema migrans rash
Evidence checked November 2, 2026. General information only; the choice and length of any antibiotic course belong to your prescriber or dentist.