Amoxicillin — Antibiotic Medication Guide | KiwiMeds
✅ Reviewed by a Registered Pharmacist NZ | Last updated: May 2026 | This information is for educational purposes only and does not replace advice from your doctor or pharmacist.
What is amoxicillin?
Amoxicillin is a penicillin-type antibiotic and one of the most commonly prescribed medicines in New Zealand. It is used to treat a wide range of bacterial infections. Generic amoxicillin is funded by Pharmac. Brand names include Alphamox and Ibiamox.
What is it used for? (NZ context)
Amoxicillin is used for chest infections (including community-acquired pneumonia), ear infections (otitis media), throat infections (tonsillitis, strep throat), urinary tract infections (UTIs), skin infections, and dental infections. It is a first-choice antibiotic for many common infections in NZ.
How does it work?
Amoxicillin kills bacteria by disrupting the construction of their cell walls. It belongs to the beta-lactam class of antibiotics and is effective against a wide range of bacteria (broad-spectrum). It does not work against viruses — this is why antibiotics are not prescribed for colds and flu.
How to take it
Always take amoxicillin exactly as directed by your doctor or pharmacist. Do not stop or change your dose without medical advice.
Common side effects
- Diarrhoea — very common
- Nausea and stomach upset
- Skin rash — mild rashes can occur; severe rashes need immediate attention
- Thrush (oral or vaginal Candida infection) — antibiotics can disrupt normal bacteria, allowing yeast to overgrow
- Headache
Serious side effects to watch for
Severe allergic reactions (anaphylaxis) can occur with penicillin antibiotics. Signs include: difficulty breathing, throat swelling, severe rash, rapid heart rate, collapse. This is a medical emergency — call 111 immediately. If you have had a severe reaction to penicillin before, always tell every healthcare provider.
Important drug interactions
- Warfarin — amoxicillin can enhance its blood-thinning effect; monitor INR closely
- Oral contraceptives — evidence is limited but some people are counselled to use additional contraception during a course; discuss with your pharmacist
- Methotrexate — amoxicillin may increase its levels
- Probenecid — may increase amoxicillin levels in the blood
NZ-specific information
Pharmac funding: Amoxicillin is fully funded. Available as capsules (250mg, 500mg), tablets, and liquid suspension. Completing the course: Always complete the full course of antibiotics even if you feel better — stopping early can allow surviving bacteria to develop resistance. Antibiotic resistance: New Zealand is working hard to combat antibiotic resistance; only take antibiotics when prescribed by a doctor.
Frequently asked questions
I’m allergic to penicillin — can I take amoxicillin? No. Amoxicillin IS a penicillin. If you have had a penicillin allergy, tell your prescriber and alternative antibiotics can be used. Can I drink alcohol while taking amoxicillin? Amoxicillin does not interact severely with alcohol, but alcohol can impair your immune system’s recovery. Moderate drinking is generally acceptable.
Related medications
Ibuprofen (pain/inflammation) | Paracetamol (pain relief) | Omeprazole (stomach protection)
Always talk to your pharmacist or doctor for personalised advice. This information is general and educational — it does not replace a consultation with your healthcare provider.
References & Further Information
The following New Zealand and international resources were used to inform this page: