Indications
Clavulanic acid is not used on its own. It is combined with Amoxicillin (a penicillin antibiotic) to treat bacterial infections, including:
- Ear, sinus, throat and tonsil infections.
- Chest infections such as bronchitis and pneumonia.
- Urinary tract infections.
- Skin and soft tissue infections, including animal and human bites.
- Dental infections and abscesses.
- Bone, joint and abdominal infections, usually in hospital.
It does not work against viral infections such as colds and flu.
How It Works
Some bacteria make enzymes called beta-lactamases that destroy Amoxicillin. Clavulanic acid blocks these enzymes, protecting Amoxicillin so it can kill a wider range of bacteria by damaging their cell walls.
Dosage and Administration
- Adults, tablets: commonly one 625 mg tablet (500 mg Amoxicillin with 125 mg clavulanic acid) three times a day, or one 1 g tablet (875 mg with 125 mg) twice a day, usually for 5 to 7 days, or as prescribed.
- Children: liquid doses are based on body weight, as prescribed.
- Injections are given by a doctor or nurse in hospital.
- People with kidney disease may need a lower dose, as prescribed.
Take at the start of a meal to reduce stomach upset and help absorption. Finish the full course even if you feel better.
Interactions
- Warfarin and similar blood thinners: bleeding risk may rise; blood tests may be needed.
- Methotrexate: levels may rise, increasing side effects.
- Allopurinol: higher chance of skin rash.
- Probenecid increases Amoxicillin levels.
- Mycophenolate: levels may fall.
- Vomiting or diarrhoea may make the contraceptive pill less reliable; use extra protection if this happens.
Contraindications
- Allergy to penicillins, or a serious allergic reaction to cephalosporins or other beta-lactam antibiotics.
- Previous jaundice or liver problems caused by Amoxicillin with clavulanic acid.
Side Effects
Common: diarrhoea, nausea, vomiting, indigestion, thrush (mouth or vaginal yeast infection) and mild skin rash. Liver problems can occur, sometimes during or up to several weeks after treatment, and are more likely in older people and with longer courses. Get urgent medical help if you have swelling of the face, lips or throat, difficulty breathing, a widespread rash with blisters or peeling skin, yellow skin or eyes, dark urine or pale stools, or severe or bloody diarrhoea (which can happen even weeks after finishing).
Pregnancy and Lactation
It is used in pregnancy when a doctor decides it is needed; the doctor may choose another antibiotic in some situations near delivery. Small amounts pass into breast milk. It is generally considered compatible with breastfeeding, but watch the baby for diarrhoea, thrush or rash and tell the doctor.
Precautions and Warnings
Tell the doctor about any allergy, liver or kidney disease, or glandular fever (infectious mononucleosis), as a rash is more likely. Take only when prescribed, at the right dose and for the full course; this helps prevent antibiotic resistance. Drink plenty of fluids during treatment.
Overdose
An overdose mainly causes nausea, vomiting and diarrhoea. Very large doses, especially with kidney problems, can rarely cause crystals in the urine or fits. Seek medical help.
Therapeutic Class
Penicillin antibiotic combined with a beta-lactamase inhibitor.
Storage
Tablets: store below 25°C in a dry place, in the original pack to protect from moisture, and out of the reach of children. Dry powder for suspension: store below 25°C; once mixed with water, keep in the fridge at 2 to 8°C and use within 7 days, or as directed on the pack.
Prepared by the Oshud Alo team from standard drug references. For information only; always follow your doctor's advice.