Amoxicillin Interactions

Amoxicillin can reduce the elimination of methotrexate from your body, which can increase your risk of developing side effects. If you are taking these medications together your doctor may want to increase your normal methotrexate monitoring (testing your blood, liver and kidneys). You should also report any side effects such as a sore throat to your doctor.

Certain blood thinners (anticoagulants), including warfarin, may interact with amoxicillin. This may increase your risk of bleeding, therefore it is important to let whoever monitors your blood thinner testing (INR) know you are taking it.

Allopurinol, a medication to treat gout, can interact with amoxicillin, causing an increased risk of developing a skin rash. You should speak to your doctor if this occurs.

Amoxicillin can reduce the effectiveness of the oral typhoid vaccine. It therefore should not be taken within three days (before or after) of the vaccine. Let your doctor know if you are taking amoxicillin and are due to have this vaccine.

If you suffer from vomiting and diarrhoea as a side effect of amoxicillin, be sure that you discuss it with your doctor. If you are unable to take your other regular medication, some issues may arise. One example would be the contraceptive pill, which can put you at risk of pregnancy if you are unable to take it or keep it down. There are many other important medications that can’t be missed and it is something to think carefully about or discuss with your doctor.

Medications to Be Cautious About:

1. Antacids

   • Antacids containing aluminium or magnesium hydroxide (e.g., Gaviscon, Rennie) may reduce the absorption of amoxicillin, potentially lowering its effectiveness.

2. NSAIDs (e.g., ibuprofen):

   • It is generally safe, but excessive use could increase the risk of kidney strain, especially if you are already dehydrated or have kidney concerns. Consult a healthcare provider if unsure.

3. Laxatives:

   • Some laxatives, especially those with magnesium (e.g., milk of magnesia), may also reduce amoxicillin absorption.

Amoxicillin is unlikely to interact with any other over-the-counter medicines, however you should speak with your pharmacist first before deciding to start taking any new over-the-counter medicines alongside amoxicillin.

There are some herbal medicines that can interact with amoxicillin such as acacia, chewing catha and bromelain. There's a limited number of studies on the safety of taking herbal medicines alongside prescribed medications, so generally it is best to avoid doing so.

Although alcohol does interact with some medications including antibiotics, this is not the case for amoxicillin. Alcohol in moderation can be taken usually without side effects. Amoxicillin can be taken either with food or on an empty stomach, however, taking it with food may be beneficial if the medicine is making you feel nauseous at all.