Dosage

The proportions of the two constituents are expressed as x/y where x and y are the strengths in milligrams of amoxicillin and clavulanic acid respectively. However, the branded products indicate their strengths as the quantity of amoxicillin, hence co-amoxiclav 250/125 ≡ Augmentin 250 and contains 250 mg of amoxicillin with 125 mg of clavulanic acid.[1][2]

Standard adult dosages for respiratory tract, urinary, abdominal, and dental infections as well as animal bites is co-amoxiclav 250/125 (one tablet Augmentin 250) taken every 8 hours, which may be doubled in severe infections (as a single tablet of co-amoxiclav 500/125 ≡ Augmentin 500, but not as two co-amoxiclav 250/125 tablets which would double the maximum recommended dose of clavulanic acid). In the US, Augmentin XR (co-amoxiclav 1000/62.5) is marketed for use in community acquired pneumonia with two tablets taken twice a day (giving 4000 mg total daily dose of amoxicillin).

From the prescribing information for Augmentin,[2] the usual adult dose is one 500-mg tablet of Augmentin every 12 hours or one 250-mg tablet of Augmentin every 8 hours. For more severe infections and infections of the respiratory tract, the dose should be one 875-mg tablet of Augmentin every 12 hours or one 500-mg tablet of Augmentin every 8 hours.

Dosages for children are also given three times a day using suspensions containing co-amoxiclav 250/62 in each 5 mL (Augmentin '250/62 SF') for those between the ages of 6–12 years and co-amoxiclav 125/31 (Augmentin '125/31 SF') for those between the ages of 1–6 years. A more concentrated solution, co-amoxiclav 400/57 (Augmentin '400/57 SF'), may be administered more conveniently just twice daily to children from as young as 2 months of age; quantities are based on body weight with 2.5 mL from the age of 2 years and 5 mL after the age of 6 years.

An intravenous preparation of Co-amoxiclav has been available in the UK since 1985,[3] but there is no parenteral preparation available in the US: the nearest equivalent is ampicillin-sulbactam.