Co-amoxiclav 875/

Co-amoxiclav is the generic name for the combination of amoxicillin and clavulanic acid, identical in composition to the branded product Augmentin. It is one of the most prescribed antibiotics in primary and secondary care, extending amoxicillin's spectrum to cover beta-lactamase-producing bacteria.

Why clavulanic acid matters

Many common pathogens, including Staphylococcus aureus, Haemophilus influenzae, Moraxella catarrhalis, and some Enterobacteriaceae, produce beta-lactamase enzymes that destroy amoxicillin's beta-lactam ring. Clavulanic acid acts as a suicide inhibitor of these enzymes, binding irreversibly to them and protecting the amoxicillin molecule. This restores effectiveness against resistant strains without needing to use a broader-spectrum antibiotic.

Clinical applications

Co-amoxiclav is prescribed for lower respiratory tract infections, acute otitis media, sinusitis, urinary tract infections, cellulitis, animal and human bites, dental abscesses, and intra-abdominal infections. It is often the empirical choice when beta-lactamase-producing organisms are suspected.

How to Take Co-amoxiclav

Take co-amoxiclav at the start of a meal to reduce gastrointestinal side effects and to improve absorption of the clavulanic acid component. Space doses evenly throughout the day and complete the full prescribed course, even if you feel better before it ends.

The 625 mg (amoxicillin 500 mg / clavulanic acid 125 mg) tablets are taken three times daily. The 1 g (amoxicillin 875 mg / clavulanic acid 125 mg) tablets are taken twice daily. The twice-daily option delivers less total clavulanic acid per day and tends to cause less diarrhoea for many people.

Completing the Course

Stopping early risks the infection recurring and can contribute to antibiotic resistance. If you miss a dose, take it as soon as you remember and continue. Do not double up doses.

625 mg (500/125) three times daily, or 1 g (875/125) twice daily. Duration: five to seven days for most infections. Dose reduction in renal impairment.

Common Side Effects

• Diarrhoea (more common with co-amoxiclav than with amoxicillin alone, due to the clavulanic acid)
• Nausea and vomiting
• Skin rash
• Vaginal thrush (candida overgrowth)

Cholestatic Jaundice

A recognised but uncommon side effect of co-amoxiclav is cholestatic jaundice (disrupted bile flow). It can appear during treatment or up to six weeks after finishing the course. It is more common in older patients and with prolonged use. Tell your doctor immediately if you develop yellowing of the skin or eyes, dark urine, very pale stools, or persistent upper abdominal pain. This side effect is specific to co-amoxiclav rather than plain amoxicillin.

Monitor for hepatic reactions, particularly with courses exceeding fourteen days. The risk of cholestatic hepatitis is higher with co-amoxiclav than with amoxicillin alone, and the clavulanic acid component is believed to be responsible.

Glandular fever

As with amoxicillin, a widespread rash is almost universal if co-amoxiclav is given to a patient with infectious mononucleosis. This is not a true penicillin allergy.

Contraindicated in penicillin allergy, history of co-amoxiclav-associated jaundice or hepatic dysfunction, and known hypersensitivity to clavulanic acid.