Zoxil is amoxicillin, a penicillin antibiotic. It comes as 250 mg and 500 mg capsules and as a suspension for children, and it treats bacterial infections of the chest, ear, throat, sinuses, urinary tract, skin and teeth. It does nothing for colds or flu, which are viral.
What is Zoxil?
Zoxil contains amoxicillin. The South African Medicine Price Registry lists four presentations, all Schedule 4 (prescription-only):
| Product | Form | Strength |
|---|---|---|
| Zoxil 250 | Capsule | Amoxicillin 250 mg |
| Zoxil 500 | Capsule | Amoxicillin 500 mg |
| Zoxil S | Suspension | 125 mg per 5 ml |
| Zoxil SF | Suspension | 250 mg per 5 ml |
Amoxicillin is a broad-spectrum penicillin. It works by preventing bacteria from building their cell walls, so they cannot maintain their structure and break down. Because it kills bacteria rather than merely slowing them, and because it is absorbed well when swallowed, it is one of the most widely prescribed antibiotics in the world.
The “250” and “500” that people search for are simply the amount of amoxicillin per capsule. The two suspensions are the paediatric forms, dosed by a child’s weight — the SF version is double the concentration, so the two are not interchangeable spoon-for-spoon.
Other South African amoxicillin brands include Amoxil, Almox and Betamox. Being dispensed one instead of another is normal generic substitution.
What is Zoxil commonly used for?
Amoxicillin is prescribed for bacterial infections including:
- Chest infections — bronchitis and community-acquired pneumonia.
- Middle ear infection (otitis media), especially in children.
- Sinusitis where it has become bacterial and is not settling.
- Tonsillitis and throat infection caused by streptococcus.
- Urinary tract infections, depending on local resistance patterns.
- Dental infections and abscesses, alongside dental treatment.
- Skin and soft tissue infections.
- Helicobacter pylori eradication, as part of a combination with other medicines for stomach ulcers.
It is a common first choice in children because the suspension is palatable, dosing is well established, and it is generally well tolerated.
It will not help a cold, flu or most sore throats and coughs, which are caused by viruses. Taking an antibiotic for a viral illness gives you the side effects without any benefit, and contributes to resistance.
How Zoxil fits into this medicine category
| Group | Examples | Typical role |
|---|---|---|
| Aminopenicillins | Amoxicillin (Zoxil, Amoxil) | Broad first-line cover for common infections |
| Penicillin + inhibitor | Co-amoxiclav | Where bacteria produce enzymes that destroy plain amoxicillin |
| Narrow penicillins | Phenoxymethylpenicillin | Streptococcal throat infection specifically |
| Macrolides | Azithromycin, erythromycin | Alternative in penicillin allergy; atypical chest infections |
| Nitroimidazoles | Metronidazole | Anaerobic and dental infections, some parasites |
| Quinolones | Ciprofloxacin | Reserved for specific infections |
Zoxil sits at the top of that table — the workhorse. Where an infection does not respond, the usual next step is co-amoxiclav, which pairs the same amoxicillin with clavulanic acid to defeat bacterial resistance enzymes. See the antibiotics and antimicrobials hub.
What to check before using Zoxil
Penicillin allergy is the critical check. If you have ever reacted to penicillin, amoxicillin, ampicillin, co-amoxiclav or a cephalosporin, say so before the first dose. Reactions range from a rash to anaphylaxis, and a previous mild reaction does not guarantee the next will be mild.
Also tell your doctor or pharmacist if you:
- Have kidney disease — the dose may need adjusting.
- Have glandular fever (infectious mononucleosis). Amoxicillin very commonly causes a widespread rash in this situation. It is not usually a true allergy, but it is avoided for that reason.
- Take methotrexate or allopurinol.
- Take warfarin — antibiotics can affect anticoagulation control.
- Use the combined oral contraceptive pill and develop vomiting or diarrhoea during the course, which can reduce absorption.
- Are pregnant or breastfeeding. Amoxicillin is generally considered acceptable, but confirm with your clinician.
Finish the full course as prescribed, even once you feel better. Stopping early leaves the hardier bacteria behind. Capsules can be taken with or without food; suspensions should be shaken well and measured with the supplied device, not a kitchen spoon.
Possible cautions and when to ask a pharmacist or doctor
The most common side effects are nausea, diarrhoea and a mild rash. Mild diarrhoea is expected with broad-spectrum antibiotics because they disturb normal gut bacteria along with the target.
Two situations need prompt attention:
Signs of a serious allergic reaction — swelling of the face, lips or tongue, difficulty breathing, widespread hives, or a rash with blistering or peeling. Get emergency help immediately. Stop taking the medicine.
Severe, watery or bloody diarrhoea, especially with fever or abdominal cramps, during or in the weeks after a course. This may indicate a Clostridioides difficile infection and needs medical assessment rather than an anti-diarrhoeal from the shelf.
Thrush — oral or vaginal — is common after antibiotics and is easily treated.
Contact your doctor if the infection is not improving after two to three days, if fever climbs, if you become short of breath, or if new symptoms appear. Not improving may mean the bacteria are resistant to amoxicillin, or that the illness is not bacterial at all.
Related medicine guides
Frequently asked questions
What is Zoxil 500 mg used for? Bacterial infections of the chest, ear, sinuses, throat, urinary tract, skin and teeth. The 500 mg capsule is the usual adult strength; 250 mg is the lower one.
Is Zoxil an antibiotic? Yes — it is amoxicillin, a penicillin antibiotic.
Will Zoxil help flu or a cold? No. Those are viral infections and antibiotics have no effect on them.
What is the difference between Zoxil S and Zoxil SF? Both are suspensions for children. Zoxil S is 125 mg per 5 ml and Zoxil SF is 250 mg per 5 ml — double the strength. Use the exact product prescribed and the measuring device supplied.
Can I take it if I am allergic to penicillin? No. Amoxicillin is a penicillin. Tell your prescriber so an alternative such as a macrolide can be used.
Can I stop once I feel better? Finish the prescribed course unless your doctor tells you otherwise.