Amoxicillin/Clavulanate: Price, Dosage & Where to Buy

Amoxicillin/clavulanate is an antibiotic combination containing the penicillin-class antibacterial amoxicillin and a beta-lactamase inhibitor, clavulanate, used for bacterial infections such as those affecting the ear, nose and throat. It requires a prescription in the United Kingdom and is available as a generic medicine; the amoxicillin label describes treatment only for infections caused, or strongly suspected to be caused, by susceptible bacteria.

Amoxicillin is indicated for susceptible bacterial infections of the ear, nose and throat, urinary and genital tract, skin and underlying tissues, and lower respiratory tract in adults and children. The amoxicillin label limits these indications to specified susceptible bacteria that do not produce beta-lactamase. In adults, it also describes amoxicillin alongside lansoprazole, with or without clarithromycin, for Helicobacter pylori infection associated with duodenal ulcer disease.

Eliminating this bacterium reduces the risk of the ulcer returning. These indications are described for amoxicillin alone and should not be interpreted as a complete list of approved uses for every amoxicillin/clavulanate product.

Amoxicillin belongs to the penicillin family of antibiotics. It interferes with the construction of the protective cell wall that bacteria need to maintain their structure, leading to the death of susceptible bacteria. Some bacteria produce enzymes called beta-lactamases that can break down certain penicillin antibiotics.

Clavulanate inhibits some of these enzymes, helping protect amoxicillin from being broken down. This combination does not overcome every form of bacterial resistance, so its activity depends on the bacteria involved.

The label lists powder for oral suspension containing 200 mg/5 mL amoxicillin with 28.5 mg/5 mL clavulanate, and 400 mg/5 mL amoxicillin with 57 mg/5 mL clavulanate. The detailed dosing schedules described below relate to amoxicillin alone, rather than establishing a dosing schedule for the combination suspension. The label lists amoxicillin adult regimens of 500 mg every 12 hours or 250 mg every 8 hours for mild or moderate ear, nose, throat, skin or genitourinary infections.

The label lists amoxicillin regimens of 875 mg every 12 hours or 500 mg every 8 hours for severe infections and lower respiratory tract infections. The label lists an upper amoxicillin dose of 30 mg/kg/day divided every 12 hours for infants aged 3 months or younger.

Severe kidney impairment requires adjustment of amoxicillin dosing. The appropriate combination-product regimen needs confirmation against its own prescription and label.

A missed antibiotic dose can interrupt the prescribed treatment schedule. General pharmacy guidance is to resume the prescribed schedule when remembered, unless the next dose is nearly due, and to avoid doubling doses. A pharmacist can clarify the appropriate timing for the particular prescription and formulation.

Animal studies of amoxicillin found no evidence of harm to the fetus, but adequate, well-controlled studies in pregnant women are lacking. The label states that amoxicillin should be used during pregnancy only if clearly needed.

Penicillins pass into human milk, and amoxicillin may sensitise breastfed infants, so caution is advised. These statements concern amoxicillin; pregnancy and breastfeeding use of the combination should be discussed with a doctor or pharmacist.

The label specifies storage of unreconstituted powder for oral suspension at 20° to 25°C in a tight container. For the amoxicillin suspension described in the label, the bottle should remain tightly closed; refrigeration is preferable but not required, and unused suspension must be discarded after 14 days.