Amoxicillin is also sometimes used together with another antibiotic called clarithromycin (Biaxin) to treat stomach ulcers caused by Helicobacter pylori infection. This combination is sometimes used with a stomach acid reducer called lansoprazole (Prevacid).
Amoxicillin 500mg and 250mg are available as tablets or capsules and as an oral suspension. Many brands and forms of amoxicillin are available, and not all brands are listed on this leaflet.
Common amoxicillin side effects
Common amoxicillin side effects may include nausea, vomiting, diarrhea, or rash. These side effects affected more than 1% of patients in clinical trials.
Serious amoxicillin side effects
Get emergency medical help if you have signs of an allergic reaction to amoxicillin (hives, difficult breathing, swelling in your face or throat) or a severe skin reaction (fever, sore throat, burning eyes, skin pain, red or purple skin rash with blistering and peeling).
Call your doctor at once if you have:
- severe stomach pain; or
- diarrhea that is watery or bloody (even if it occurs months after your last dose).
Do not use this medication if you are allergic to amoxicillin or to any other penicillin antibiotic, such as ampicillin (Omnipen, Principen), dicloxacillin (Dycill, Dynapen), oxacillin (Bactocill), penicillin (Beepen-VK, Ledercillin VK, Pen-V, Pen-Vee K, Pfizerpen, V-Cillin K, Veetids), and others.
Before using amoxicillin, tell your doctor if you are allergic to cephalosporins such as Omnicef, Cefzil, Ceftin, Keflex, and others. Also, tell your doctor if you have asthma, liver or kidney disease, a bleeding or blood clotting disorder, mononucleosis (also called "mono"), or any type of allergy.
Amoxicillin can make birth control pills less effective. Ask your doctor about using a non-hormone method of birth control (such as a condom, diaphragm, or spermicide) to prevent pregnancy while taking this medicine. Take this medication for the full prescribed length of time. Your symptoms may improve before the infection is completely cleared. Amoxicillin will not treat a viral infection such as the common cold or flu. Do not share this medication with another person, even if they have the same symptoms you have.
Antibiotic medicines can cause diarrhea. This may happen while you are taking amoxicillin, or within a few months after you stop taking it. This may be a sign of a new infection. If you have diarrhea that is watery or bloody, stop taking this medicine and call your doctor. Do not use anti-diarrhea medicine unless your doctor tells you to.
There's an increased risk of side effects if you take 2 doses closer together than recommended. Accidentally taking 1 extra dose of your antibiotic is unlikely to cause you any serious harm. But it will increase your chances of getting side effects, such as pain in your stomach, diarrhoea, and feeling or being sick.