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: Kidney disease or reduced kidney function may cause this medication to build up in the body, causing side effects. If you have kidney disease, discuss with your doctor how this medication may affect your medical condition, how your 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. Talk to your doctor if you have any concerns.
Pregnancy: This medication is generally considered safe in pregnancy. If you are pregnant, discuss with your doctor this risks and benefits of taking this medication. 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.