In this drug factsheet:
What side effects are possible with this medication?
Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent. The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.
The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.
Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.
- abdominal pain (mild)
- diarrhea (mild)
- loss of appetite
- sore mouth
- swollen tongue or black "hairy" tongue
Although most of these side effects listed below don't happen very often, they could lead to serious problems if you do not check with your doctor or seek medical attention.
Check with your doctor as soon as possible if any of the following side effects occur:
- abdominal pain (severe)
- any new infection
- shortness of breath
- skin rash, hives, or itching
- symptoms of liver damage (e.g., yellow skin or eyes, abdominal pain, dark urine, clay-coloured stools, loss of appetite)
- unusual tiredness or weakness
Stop taking the medication and seek immediate medical attention if any of the following occur:
- convulsions (seizures)
- diarrhea (watery and severe), which may also be bloody
- symptoms of a serious allergic reaction (e.g., swelling of the face or throat, difficulty breathing, wheezing, or itchy skin rash)
Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.
Are there any other precautions or warnings for this medication?
Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.
Allergy: Amoxicillin is a penicillin and should not be used by anyone with a penicillin allergy or an allergy to the class of medications called cephalosporins. People who have allergies in general should watch carefully for any reaction to amoxicillin when starting a new prescription. In rare cases, some people may develop a serious allergic reaction to this medication. Signs of an allergic reaction include a severe rash, hives, swollen face or throat, or difficulty breathing. If these occur, seek immediate medical attention.
Birth control: Penicillins may decrease the effectiveness of birth control pills. Some doctors recommend adding another method of birth control for the rest of the cycle when penicillin is taken.
Diarrhea: This medication is associated a serious infection called Clostridium difficile-associated diarrhea, caused by the bacteria C. difficile. This can occur even after your last dose of this medication. If you have severe diarrhea (with or without fever or blood) after taking amoxicillin, get medical attention as soon as possible.
Kidney disease: People with kidney disease should discuss with their doctor how this medication may affect their medical condition, how their medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.
Medical conditions: When amoxicillin is used by a person who has mononucleosis, acute lymphocytic leukemia (a type of cancer that affects white blood cells), or cytomegalovirus infection (a viral infection), a widespread rash may occur. Talk to your doctor if you have any concerns.
Overgrowth of organisms: Treatment with any penicillin may allow normal fungus or types of bacteria not killed by the antibiotic to overgrow, causing unwanted infections such as yeast infections, which may cause vaginal itching and irritation. Women may prevent yeast infections by eating yogurt daily while taking this antibiotic. Talk to your doctor if you have any concerns.
Pregnancy: This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.
Breast-feeding: This medication passes into breast milk. If you are a breast-feeding mother and are taking amoxicillin, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.
What other drugs could interact with this medication?
There may be an interaction between amoxicillin and any of the following:
- BCG vaccine
- birth control pills
- fusidic acid
- tetracyclines (e.g., minocycline, doxycycline)
- typhoid vaccine
If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:
- stop taking one of the medications,
- change one of the medications to another,
- change how you are taking one or both of the medications, or
- leave everything as is.
An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.
Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.