Clamentin is co-amoxiclav — amoxicillin combined with clavulanic acid. It treats bacterial infections that plain amoxicillin cannot, because the second ingredient disables the enzyme resistant bacteria use to destroy penicillins. It comes as tablets, paediatric suspensions and an injection.
What is Clamentin?
The South African Medicine Price Registry lists Clamentin across several forms, all Schedule 4:
| Product | Form | Contains |
|---|---|---|
| Clamentin 375 | Tablet | Amoxicillin 250 mg + clavulanic acid 125 mg |
| Clamentin | Tablet | Amoxicillin 875 mg + clavulanic acid 125 mg (the “1000”) |
| Clamentin S | Suspension | 125 mg + 31.25 mg per 5 ml |
| Clamentin SF | Suspension | 250 mg + 62.5 mg per 5 ml |
| Clamentin IV | Injection | Amoxicillin 1 g + clavulanic acid 200 mg |
The numbers on the pack are the total of both ingredients, which is why 250 + 125 is sold as “375” and 875 + 125 as “1000”.
Note that the clavulanic acid stays at 125 mg while the amoxicillin rises. That means two 375 mg tablets are not equivalent to one 1000 mg tablet — doubling up doubles the clavulanic acid, which mostly adds diarrhoea rather than antibacterial effect. Take the strength you were prescribed.
The two suspensions are not interchangeable either. Clamentin S is 125 mg per 5 ml; Clamentin SF is double that. Giving a spoonful of the wrong one halves or doubles a child’s dose. Check the label before every dose, particularly if a child has had a different bottle before.
How the combination works. Amoxicillin blocks bacteria from building their cell walls. Many bacteria defend themselves by producing beta-lactamase, an enzyme that destroys amoxicillin before it can act. Clavulanic acid has almost no antibacterial activity of its own — its job is to bind and disable that enzyme, leaving the amoxicillin free to work. It is a chemical bodyguard rather than a second antibiotic.
What is Clamentin commonly used for?
- Chest infections — bronchitis and pneumonia, particularly where amoxicillin has failed.
- Sinusitis that is not settling.
- Middle ear infection, especially recurrent or unresponsive cases in children.
- Urinary tract infections, including some kidney infections.
- Dental infections and abscesses, alongside dental treatment.
- Skin and soft tissue infections, including cellulitis and infected wounds.
- Animal and human bites. Co-amoxiclav is specifically preferred here, because bite wounds carry a mix of organisms it covers well.
- Bone, joint and intra-abdominal infections, usually starting intravenously.
- Preventing infection around some surgery.
It will not help colds, flu or most sore throats and coughs, which are viral.
Co-amoxiclav is deliberately a second-line choice in many settings. It is broader than amoxicillin, which means it kills more of your normal bacteria alongside the target and puts more pressure on resistance. Being prescribed it means someone judged that breadth necessary — not that your infection is trivial.
How Clamentin fits into this medicine category
| Group | Examples | Typical role |
|---|---|---|
| Penicillin + inhibitor | Co-amoxiclav (Clamentin) | Where beta-lactamase defeats plain amoxicillin |
| Aminopenicillins | Amoxicillin | Broad first-line cover |
| Penicillinase-resistant | Cloxacillin, flucloxacillin | Staphylococcal skin and soft tissue infection |
| Macrolides | Azithromycin (Azrotrin), erythromycin | Alternative in penicillin allergy; atypical pneumonia |
| Nitroimidazoles | Metronidazole | Anaerobic and dental infections |
| Cephalosporins | Cefuroxime, ceftriaxone | Alternative broad cover |
See the antibiotics and antimicrobials hub.
What to check before using Clamentin
Penicillin allergy is the critical check. If you have ever reacted to penicillin, amoxicillin, co-amoxiclav or a cephalosporin, say so before the first dose. A previous mild reaction does not guarantee the next will be mild.
Also tell your doctor or pharmacist if you:
- Have liver disease, or have had jaundice or a liver reaction with co-amoxiclav before. This matters more than with most antibiotics — liver injury is uncommon but is more frequently associated with co-amoxiclav than with plain amoxicillin, is more likely in older people and with longer courses, and can appear weeks after the course ends. A previous liver reaction to it usually rules out ever taking it again.
- Have kidney disease — the dose may need adjusting.
- Have glandular fever (infectious mononucleosis), where a widespread rash is very likely — relevant in teenagers with a sore throat.
- Take warfarin, methotrexate or allopurinol.
- Are pregnant or breastfeeding. Generally considered acceptable, but confirm.
- Use the combined oral contraceptive pill and develop vomiting or diarrhoea during the course.
Practical points:
- Take it at the start of a meal. This reduces stomach upset and improves absorption — more important with co-amoxiclav than plain amoxicillin, because the clavulanic acid is what irritates the gut.
- Shake suspensions well before every dose, and use the measuring device supplied — never a kitchen spoon.
- Keep suspensions refrigerated if the label says so, and note the discard date — usually seven to fourteen days after mixing.
- Space doses evenly and complete the full course.
- Do not substitute strengths.
Possible cautions and when to ask a pharmacist or doctor
The commonest effects are diarrhoea, nausea, vomiting and rash. Diarrhoea is notably more common with co-amoxiclav than with amoxicillin alone, and is caused by the clavulanic acid.
Get emergency help for:
- Swelling of the face, lips or tongue, difficulty breathing, widespread hives, or a rash with blistering or peeling — signs of a serious allergic reaction. Stop taking it.
- Severe, watery or bloody diarrhoea, especially with fever or cramping, during or in the weeks after the course — possible Clostridioides difficile infection, which needs assessment rather than an anti-diarrhoeal.
- Yellowing of the skin or eyes, dark urine, pale stools, itching, or persistent right-sided abdominal pain — possible liver injury. Seek advice even if the course finished weeks ago.
Contact your doctor if:
- The infection is not improving after two to three days, or is spreading.
- You develop fever, breathlessness, confusion, or feel markedly worse.
- Thrush develops afterwards — common after broad antibiotics and easily treated.
- A child is not improving, is drinking poorly, or is unusually drowsy.
- You have been bitten and the wound becomes red, swollen, hot or painful — bites need proper assessment, including tetanus and rabies considerations, not antibiotics alone.
Related medicine guides
Frequently asked questions
What is Clamentin 1000 mg used for? Bacterial infections of the chest, sinuses, ears, urinary tract, teeth, skin and bite wounds — particularly where plain amoxicillin has failed. It contains amoxicillin 875 mg with clavulanic acid 125 mg.
What is the difference between 375 and 1000? The amoxicillin component rises; the clavulanic acid stays at 125 mg. They are not interchangeable by combining smaller tablets.
What is the difference between Clamentin S and SF? Both are children’s suspensions. S is 125 mg per 5 ml, SF is 250 mg — double the strength. Check the label before every dose.
How is it different from amoxicillin? Clavulanic acid disables the enzyme many bacteria use to destroy amoxicillin, so the combination works where amoxicillin alone fails.
Why does it upset my stomach more? The clavulanic acid causes most of the diarrhoea and nausea. Taking it at the start of a meal helps.
Can I take it if I am allergic to penicillin? No. It contains amoxicillin, a penicillin. Tell your prescriber so an alternative can be used.
Should I worry about my liver? Liver injury is uncommon but more associated with co-amoxiclav than plain amoxicillin, and can appear weeks after the course. Report jaundice, dark urine or persistent itching even after finishing.
Will it treat flu? No. Flu is viral and antibiotics have no effect on it.