Co Maug is a prescription antibiotic containing amoxicillin with clavulanic acid. It comes as Co Maug 1 g tablets and Co Maug ES 600, a high-strength paediatric suspension. It treats chest, sinus, ear, urinary, skin and dental infections, particularly where plain amoxicillin would fail.
What is Co Maug?
Co Maug is Schedule 4 — prescription-only:
| Product | Contains |
|---|---|
| Co Maug 1 g | Amoxicillin 875 mg + clavulanic acid 125 mg tablet |
| Co Maug ES 600 | Amoxicillin 600 mg/5 ml + clavulanic acid 42.9 mg/5 ml suspension |
This combination is generally known as co-amoxiclav, and equivalents include Augmentin, Ranclav and Myclav.
Only one of the two ingredients is an antibiotic. Amoxicillin kills bacteria by preventing them building their cell walls. Clavulanic acid has almost no antibacterial activity of its own — its job is to block beta-lactamase, the bacterial enzyme that destroys penicillins before they can work. It acts as a shield, restoring amoxicillin’s effectiveness against otherwise resistant bacteria.
The “ES” suspension deserves particular attention, because it is not simply a stronger version of the ordinary one.
ES stands for “extra strength”, and the important detail is the ratio. Standard paediatric co-amoxiclav suspensions run at roughly 4:1 or 7:1 amoxicillin to clavulanic acid. ES 600 runs at 14:1 — far more amoxicillin for the same clavulanic acid.
That ratio exists for a specific clinical reason. Some ear infections, particularly resistant Streptococcus pneumoniae, need high-dose amoxicillin to be cleared. Simply giving more of a standard suspension would also deliver more clavulanic acid, which causes the diarrhoea — often enough to make the course intolerable in a small child. ES delivers the high amoxicillin dose while keeping clavulanic acid low.
The practical consequence: ES and standard suspensions are not interchangeable millilitre for millilitre. If your child’s prescription changes between them, the volume will change too. Follow the new instructions rather than the old ones, and ask the pharmacist to confirm the amount.
What is Co Maug commonly used for?
A doctor may prescribe it for:
- Middle ear infections, particularly recurrent or resistant ones — the main use for the ES suspension.
- Chest infections, including some pneumonia and infective exacerbations of COPD.
- Sinusitis, where symptoms are persistent, severe or worsening after initial improvement.
- Urinary tract infections.
- Skin and soft-tissue infections, including infected animal and human bites.
- Dental infections and abscesses, alongside dental treatment.
- Bone and joint infections, in some cases.
It has no effect on viruses. Colds, flu, most sore throats and most coughs are viral, and an antibiotic will not shorten them.
How Co Maug fits into this medicine category
| Group | Examples | Typical role |
|---|---|---|
| Penicillins | Amoxicillin, flucloxacillin | Common first-line choices |
| Penicillin + inhibitor | Co-amoxiclav (Co Maug) | Where beta-lactamase resistance is likely |
| Cephalosporins | Cefalexin | Skin, throat, urinary infections |
| Macrolides | Azithromycin | Chest infections, penicillin allergy |
| Fluoroquinolones | Ciprofloxacin | Urinary, gut and bone infections; reserved |
| Nitroimidazoles | Metronidazole | Anaerobic and some parasitic infections |
See the antibiotics and antimicrobials hub.
What to check before using Co Maug
Tell your doctor about any penicillin allergy before you start. This is the most important check, because Co Maug is a penicillin and the reaction can be severe. Describe what actually happened during the previous reaction.
Take it with food or at the start of a meal. This meaningfully reduces the stomach upset and diarrhoea caused by the clavulanic acid, and improves absorption.
Complete the full course.
For the suspension:
- Shake the bottle well before every dose.
- Use the measuring device supplied — never a kitchen spoon, which is neither accurate nor consistent.
- Check the storage instructions. Most reconstituted suspensions must be refrigerated and discarded after a set number of days.
- Confirm the volume if switching between ES and standard products.
Tell your doctor or pharmacist if you or your child:
- Have had any reaction to a penicillin or cephalosporin.
- Have had jaundice or liver problems on co-amoxiclav before. This is a specific contraindication.
- Have liver or kidney disease.
- Have glandular fever, where amoxicillin commonly causes a widespread rash.
- Take warfarin, methotrexate or allopurinol.
- Are pregnant or breastfeeding.
- Use the combined oral contraceptive pill.
Possible cautions and when to ask a pharmacist or doctor
The most common effects are diarrhoea, nausea, stomach upset and thrush. Diarrhoea is notably more common than with plain amoxicillin because of the clavulanic acid — though the ES formulation’s lower ratio is designed to reduce exactly this.
Stop and seek medical attention urgently if you or your child develop:
- Swelling of the face, lips, tongue or throat, difficulty breathing, or a widespread hives-like rash — a serious allergic reaction. Call emergency services.
- Any rash, which should be assessed rather than ignored.
- Blistering or peeling skin, or sores in the mouth or eyes.
- Severe, watery or bloody diarrhoea, during or in the weeks after the course. This may indicate a C. difficile infection, and anti-diarrhoeal medicines should not be used in that situation.
- Yellowing of the eyes or skin, dark urine or pale stools — a possible liver reaction, which can appear up to several weeks after finishing.
- Unusual bruising or bleeding.
- Much less urine than usual.
For a child, seek advice promptly if: they are not improving after two to three days, are refusing fluids, are unusually drowsy or floppy, develop a high fever, or have a rash that does not fade when pressed with a glass.
Contact your doctor if symptoms worsen at any point — the organism may not be susceptible.
Related medicine guides
- Browse Antibiotics, Antifungals & Antimicrobials guides
- Read: Azrotrin used for
- Read: Metronidazole used for
Frequently asked questions
What are Co Maug tablets used for? Bacterial infections of the chest, sinuses, ears, urinary tract, skin and teeth, particularly where resistance to plain amoxicillin is likely.
What is Co Maug 1 g used for? The tablet containing amoxicillin 875 mg with clavulanic acid 125 mg — a common adult strength for the infections above.
What is Co Maug ES 600? A high-strength paediatric suspension with a higher amoxicillin-to-clavulanic-acid ratio, used mainly for resistant ear infections in children.
Why does the ES version have a different ratio? It delivers a high amoxicillin dose without a matching increase in clavulanic acid, which is what causes diarrhoea — making a high-dose course tolerable in children.
Can I swap between ES and ordinary suspension? Not by volume. They are different concentrations and ratios. Follow the new instructions and confirm the amount with a pharmacist.
Will it help flu or a cold? No. Those are viral, and antibiotics have no effect on them.
Why does it upset the stomach? Mostly the clavulanic acid. Giving it with food or at the start of a meal reduces this considerably.
Can we stop when the child feels better? No. Finish the prescribed course unless your doctor tells you otherwise.