Amoxicillin (Antibiotic Agent)

Amoxicillin is penicillin-type antibiotic. Amoxicillin binds to penicillin-binding proteins (PBPs) that certain bacterial cell walls. This binding prevents normal crosslinking and results in a weakened cell wall that ruptures and kills the bacteria. However, antibiotics have no effect on viral infections.

Know the basics

What is amoxicillin used for? 

• Upper and lower respiratory tract infections, including ear, nose and throat infections (e.g. acute otitis media)
• Gastrointestinal tract infections
• Genitourinary tract infections
• Skin and skin structure infections
• Bone infections (e.g. osteomyelitis)
• Gall bladder / Biliary tract infections
• Helicobacter pylori infections (in combination with other drugs)
• Lyme Disease
• Dental abscess (as an adjunct to surgical management)

How should I take amoxicillin?

Oral capsules should be taken by mouth without chewing or crushing it. The oral drops and suspension require reconstitution (mixing) with clean drinking water. It can be taken with or without food, followed by a glass of water.

How do I store amoxicillin?

This drug should be stored at room temperature (<30°C) and be protected from light and moisture. Do not freeze this product. Always check the label before using this product. For safety, keep out of the reach of children and pets.

There may be different brands of this drug that may have different storage needs. So, it is important to always check the product package for instructions on storage, or ask your pharmacist. For safety, you should keep all medicines away from children and pets.

You should not flush this product down the toilet or pour them into a drain unless instructed to do so. Additionally, it is important to properly discard this product when it is expired or no longer needed. Consult your pharmacist for more details about how to safely discard your product.

Know the precautions & warnings

What should I know before using amoxicillin?

Before using this drug, tell your doctor if you are/have:

• Pregnant or breastfeeding.
• Taking any other medicines. This includes any prescription, OTC, and herbal remedies.
• An allergy to any of the ingredients of this product.
• Any other illnesses, disorders, or medical conditions.

Is it safe to take amoxicillin during pregnancy or breast-feeding?

This drug is generally safe during pregnancy and breastfeeding. Please always consult with your doctor to weigh the potential benefits and risks before taking any medication.

This medication is pregnancy risk category B according to the US Food and Drug Administration (FDA).

FDA pregnancy risk category reference below:

• A=No risk
• B=No risk in some studies
• C=There may be some risk
• D=Positive evidence of risk
• X=Contraindicated
• N=Unknown

Know the side effects

What are the side effects of amoxicillin?

Like all drugs, this product may have side effects. If they occur, side effects are generally mild and resolve once treatment is finished or the dose is lowered. Some reported side effects include:

• Nausea, vomiting
• Diarrhea
• Black “hairy” tongue
• Colitis
• Mild allergic reaction
• Tooth discoloration

Rare, serious adverse reactions:

• Hepatitis
• Nephrotoxicity
• Blood abnormalities
• Anaphylactic reaction
• Convulsions

However, not everyone experiences these side effects. In addition, some people may experience other side effects. So, if you have any concerns about a side effect, please consult your doctor or pharmacist.

Know the interactions

What drugs may interact with amoxicillin?

This medication may interact with other drugs that you are currently taking, which can change how your drug works or increase your risk for serious side effects. 

To avoid any potential drug interactions, you should keep a list of all the drugs you are using (including prescription drugs, nonprescription drugs, and herbal products) and share it with your doctor and pharmacist. 

Drugs with known interactions:

• Allopurinol
• Anticoagulants
• Bacteriostatic agents
• Beta-lactamase inhibitors
• Digoxin
• Methotrexate
• Oral contraceptives
• Probenecid

If you experience an adverse drug interaction, inform your doctor immediately to reevaluate your treatment plan. Approaches include dose adjustment, drug substitution, or ending therapy.

Does food or alcohol interact with amoxicillin?

This drug may interact with food or alcohol by altering the way the drug works or increase the risk for serious side effects. Please discuss with your doctor or pharmacist any potential food or alcohol interactions before using this drug.

What health conditions may interact with amoxicillin?

This drug may interact with underlying conditions. This interaction may worsen your health condition or alter the way the drug works. Therefore, it is important to always let your doctor and pharmacist know all the health conditions you currently have, especially:

• Allergy to penicillin or cephalosporin antibiotics
• Viral infection
• Severe kidney disease
• Phenylketonuria (PKU)

Understand the dosage

The information provided is not a substitute for any medical advice. Therefore, you should always consult with your doctor or pharmacist before using any medication.

What is the dose for an adult?

Cutaneous Bacillus anthracis:

Take 500 mg three times a day.

Bacterial Endocarditis Prophylaxis:

Take 2 g given one hour prior to the procedure.

Chlamydia Infection:

Take 500 mg 3 times a day for 7 days in pregnant patients as an alternative to erythromycin in macrolide-sensitive individuals.

Urinary Tract Infection or cystitis:

Take 250 to 500 mg 3 times a day for 3 to 7 days; alternatively, 500 to 875 mg twice a day may be administered.

Helicobacter pylori infection:

Take 1 g two to three times a day for 14 days.

Otitis Media:

Take 250 to 500 mg 3 times a day for 10 to 14 days; alternatively, 500 to 875 mg twice a day may be administered.

Pneumonia:

Take 500 mg 3 times a day or 875 mg twice a day may be administered for 7 to 10 days if pneumococcal pneumonia is suspected.

Skin or Soft Tissue Infection:

Take 250 to 500 mg 3 times a day for 7 to 10 days; alternatively, 500 to 875 mg twice a day may be administered.

Upper Respiratory Tract Infection:

Take 250 to 500 mg 3 times a day for 7 to 10 days; alternatively, 500 to 875 mg twice a day may be administered.

Bronchitis:

Take 250 to 500 mg 3 times a day for 7 to 10 days; alternatively, 500 to 875 mg twice a day may be administered.

Tonsillitis/Pharyngitis:

• Immediate-release: Take 250 to 500 mg 3 times a day for 7 to 10 days; alternatively, 500 to 875 mg twice a day may be administered.
• Extended-release: Take 775 mg once a day within 1 hour after a meal for 10 days; for infections secondary to Streptococcus pyogenes.

What is the dose for a child?

Bacterial Endocarditis Prophylaxis:

Give 50 mg/kg as a single dose 1 hour prior to procedure.

Cutaneous Bacillus anthracis:

Give 80 mg/kg/day divided into equal doses administered every 8 hours. Maximum dose: 500 mg/dose.

Otitis Media

• Age 4 weeks to 3 months: Give 20 to 30 mg/kg/day in divided doses every 12 hours.
• 4 months to 12 years: Give 20 to 50 mg/kg/day in divided doses every 8 to 12 hours; acute otitis media due to highly resistant strains of Streptococcus pneumoniae may require doses of 80 to 90 mg/kg/day divided into 2 equal doses 12 hours apart.

Skin or Soft Tissue Infections

Urinary Tract Infection

• Age 4 weeks to 3 months: 20 to 30 mg/kg/day in divided doses every 12 hours.
• 4 months to 12 years: 20 to 50 mg/kg/day in divided doses every 8 to 12 hours; acute otitis media due to highly resistant strains of Streptococcus pneumoniae may require doses of 80 to 90 mg/kg/day divided into 2 equal doses 12 hours apart.

Pneumonia:

Give 40 to 50 mg/kg/day in divided doses every 8 hours.

Tonsillitis/Pharyngitis

• Age 4 weeks to 3 months: Give 20 to 30 mg/kg/day in divided doses every 12 hours.
• 4 months to 12 years: Give 20 to 50 mg/kg/day in divided doses every 8 to 12 hour.
• 12 years or older:
  • Immediate-release: Give 250 to 500 mg 3 times a day for 7 to 10 days; alternatively, 500 to 875 mg twice a day may be administered.
  • Extended-release: Give 775 mg once a day within 1 hour after a meal for 10 days; for infections secondary to S. pyogenes.

How is amoxicillin available?

Amoxicillin is available in the following dosage forms and strengths:

• Powder for oral drops 100 mg/mL
• Powder for oral suspension 125 mg/5 mL, 250 mg/ 5 mL
• Oral capsule 250 mg, 500 mg

What should I do in case of an emergency or overdose?

In case of an emergency or an overdose, call your local emergency services or go to the nearest emergency room.

What should I do if I miss a dose?

If you miss a dose of this drug, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and take your regular dose as scheduled. Do not take a double dose. Avoid missing doses to prevent bacterial resistance and treatment failure.