Amoxicillin for ear infection: Dosage, uses, and side effects

In this article:

• Is amoxicillin good for ear infections?
• What is an ear infection?
• Ear infection causes
• Ear infection symptoms
• How ear infections are diagnosed
• Dosage for ear infections
• How long does amoxicillin take to work for ear infections?
• Side effects of amoxicillin
• Do you need antibiotics for an ear infection?
• Alternatives to amoxicillin for an ear infection

In this article

• Is amoxicillin good for ear infections?
• What is an ear infection?
• Ear infection causes
• Ear infection symptoms
• How ear infections are diagnosed
• Dosage for ear infections
• How long does amoxicillin take to work for ear infections?
• Side effects of amoxicillin
• Do you need antibiotics for an ear infection?
• Alternatives to amoxicillin for an ear infection

Amoxicillin is commonly prescribed for ear infections, especially in children and adults without penicillin allergies. It’s considered the first-line treatment for most uncomplicated ear infections caused by susceptible bacteria. Read on to learn more about amoxicillin and how it’s used for ear infections, including dosage, possible side effects, and alternatives your healthcare provider may consider.

Is amoxicillin good for ear infections?

Yes. Amoxicillin is typically the antibiotic of choice for bacterial infections in people who aren’t allergic to penicillin. It works well in children with ear infections because it can penetrate middle ear fluid and is effective against the bacteria that commonly cause ear infections. 

However, antibiotics like amoxicillin won’t treat ear infections that are caused by a virus. Your healthcare provider will take into account factors like your timeline of illness, symptoms, and other in-office investigations to determine whether amoxicillin can help with your symptoms or not. 

What is an ear infection?

An ear infection (acute otitis media) is an infection that occurs in the middle ear. The infection may be caused by bacteria or viruses. It is most common in young children and often occurs after an upper respiratory tract infection. 

Ear infection causes

Ear infections can be caused by viruses, bacteria, or both. Typically, an ear infection follows an upper respiratory infection (URI). “That initial URI is typically a cold or virus. This could be caused by any number of viruses, such as influenza, coronavirus, rhinovirus, or adenovirus. The swelling of the nasopharynx from this infection can block the eustachian tube drainage, resulting in the middle ear collecting bacteria,” Dr. Marcellino explains.

The most common bacteria that cause ear infections are Streptococcus pneumoniae (S. pneumoniae), Haemophilus influenzae (H. influenzae), and Moraxella catarrhalis, according to StatPearls.

Factors that can increase the risk of ear infections include:

• Weakened immune systems due to human immunodeficiency virus (HIV), diabetes, or other conditions
• Allergies
• Family history of recurrent ear infections in parents or siblings
• Younger age
• Upper respiratory tract infections
• Exposure to smoke or substances that irritate the airways
• Viral infections from respiratory syncytial virus (RSV), influenza virus, parainfluenza virus, rhinovirus, and adenovirus

Ear infection symptoms

Symptoms of an ear infection can differ slightly between adults and children. “An active infection will come with pain, pressure, and decreased hearing. In small children, we sometimes only see general fussiness, but in adults, they can usually pinpoint the problem as ear-related,” Dr. Djalilian shares.

In children, symptoms of an ear infection include:

• Low-grade fever
• Pulling or tugging at the ears
• Irritability
• Restless or disturbed sleep 
• Poor appetite 
• Vomiting 
• Diarrhea

In adults, ear infection symptoms may include:

• Ear pain
• Fever
• Irritability 
• Decreased or muffled hearing

In some cases, ear infections can cause tears (perforations or rupture) in the eardrum (tympanic membrane). This can feel like a sudden relief of pressure, and the patient might notice fluid coming out of the ear. 

Ear infection diagnosis

To diagnose an ear infection, healthcare providers may also use an otoscope to look into your ear canal. “We diagnose ear infections by using an otoscope (think small, handheld microscope, with a light attached) to examine the eardrum and the middle ear space,” explains AJ Marcellino, MD, board-certified ear, nose, and throat (ENT) specialist and Medical Director of Radiant Medical Aesthetics in Greensboro, North Carolina. 

“For young children, it can sometimes be tricky because if a child is crying, the eardrum can also appear red and irritated,” says Hamid Djalilian, MD, Professor of Otolaryngology, Neurosurgery, and Biomedical Engineering at the University of California, Irvine, and the chief medical adviser at NeuroMed Tinnitus Care. “Another tough situation is when there’s some fluid behind the eardrum, but it doesn’t look infected (called serous otitis media). In these cases, antibiotics are not called for, so it’s a balance between the physical exam and clinical judgment,” he says.

Amoxicillin for ear infection dosage

The dosage of amoxicillin will depend on the severity of your infection, age, and weight. In children who weigh 40 kilograms or less, the dosage can range from 20 to 40 mg of amoxicillin per kilogram body weight per day in divided doses every 8 hours. Children who weigh above 40 kg usually take the adult dose. In adults, amoxicillin dosages can range from 250 mg three times daily to 875 mg twice daily. 

Your healthcare professional may adjust your prescription based on your health history, your immune system function, weight, and age. 

Whatever your healthcare provider recommends, it’s important to follow your dosing instructions exactly and finish your course of antibiotics. Missing doses or stopping antibiotics early may lead to resistant infections that require stronger alternative antibiotics. 

How long does amoxicillin take to work for ear infections?

Antibiotics can offer a lot of relief for people with ear infections. “Most people feel meaningful relief within one to two days of starting treatment, although the ear can feel ‘blocked’ while waiting for the now sterile fluid to clear,” Dr. Djalilian explains.

Those who have recurrent ear infections or have recently taken amoxicillin may be prescribed a combination antibiotic, amoxicillin-clavulanate, that may better treat certain types of bacterial infections. Amoxicillin clavulanate works better for ear infections caused by bacteria H. influenzae and M. catarrhalis. 

Amoxicillin for ear infection side effects and risks

There are side effects that may occur from taking amoxicillin. The most common side effects are digestive system-related symptoms, but there are other serious risks of side effects to keep in mind.

Common side effects of amoxicillin include:

• Diarrhea
• Rash
• Vomiting
• Nausea
• Allergic reactions, e.g., anaphylactic reactions
• Yeast infection
• Clostridiodes difficile (C. diff) infection and diarrhea

C. diff-associated diarrhea is more likely in hospital or healthcare settings, and is a potentially serious infection that can develop when someone uses antibiotics. C. diff infections can cause severe diarrhea, abdominal pain, dehydration, and inflammation in the gut, which may require more treatment or hospitalization. 

When infections aren’t cleared by the right treatment, antibiotic use can lead to treatment-resistant strains of bacteria. Repeated, unnecessary, or incorrect antibiotic use contributes to something called antibiotic resistance, which makes future infections harder to treat. For this reason, amoxicillin should only be used exactly as prescribed to reduce the risk of resistant infections that can cause further complications. 

Do you need antibiotics for an ear infection?

It’s common to receive a prescription for amoxicillin if your healthcare provider suspects an ear infection. Dr. Djalilian explains that, while antibiotic resistance is still a risk, studies suggest that roughly 85% of bacteria isolated from ear infections are susceptible to amoxicillin. “Many of the highly resistant strains that parents worry about are not the dominant drivers of routine ear infections,” he explains.

There are certain cases where clinicians may watch and wait before prescribing antibiotics, such as if your child has mild symptoms. These may include a lack of pus or fluid coming from the ear, no signs of a fever, or symptoms that have only lasted less than two days. However, severe symptoms may warrant antibiotic use. These may include:

• Fever with a temperature of 102.2°F or higher
• Pus, discharge, or fluid coming from the ear
• Hearing loss
• Symptoms lasting more than two to three days

Healthcare professionals can help determine whether or not a child needs antibiotics. Therefore, it is a good idea to consult your healthcare provider if your child has symptoms of an ear infection. 

Though there are no specific studies for adults with ear infections, antibiotics may be recommended in order to prevent complications. Untreated or unmanaged ear infections can lead to further infections in the inner ear, jaw, and brain. 

Alternatives to amoxicillin for an ear infection

Amoxicillin is the first-choice antibiotic for ear infections, but there are other options available that healthcare providers may consider:

• Azithromycin or cefdinir may be considered for people allergic to penicillin
• Augmentin (amoxicillin-clavulanate), a combination antibiotic, may be given if amoxicillin doesn’t improve symptoms within 48 to 72 hours or if amoxicillin has been taken recently.
• Ceftriaxone may be given as an injection for children who are vomiting.
• Non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen or acetaminophen (Tylenol) may be given for pain management

“In more stubborn or recurrent cases, a short course of a cephalosporin can also be effective,” Dr. Djalilian says.

Healthcare providers may consider inserting tubes in the eardrum to relieve severe or recurrent ear infections. Seeing a specialist, such as an otolaryngologist (ear, nose, throat (ENT) specialist), may be helpful to rule out other causes of ear infections.

The bottom line 

Amoxicillin is a commonly prescribed antibiotic, and it’s recommended as the first-choice treatment for ear infections. Amoxicillin is expected to improve symptoms of ear infections within two to three days. However, there are certain patients for whom amoxicillin may not be recommended, including people who are allergic to penicillin or children who have mild symptoms of an ear infection. 

Though antibiotics like amoxicillin are potent and effective treatments, it’s important to use them only when needed and exactly as directed to prevent antibiotic resistance. Talk to your healthcare professional if you have any questions about ear infection symptoms or treatment.