Coamoxiclav

Co-amoxiclav, also called amoxicillin–clavulanic acid, is a fixed-dose antibiotic that pairs amoxicillin with clavulanic acid, a beta-lactamase inhibitor. The clavulanic acid protects amoxicillin from inactivation by beta-lactamase enzymes produced by certain bacteria, extending the drug’s spectrum to beta-lactamase–producing strains. It is available in oral formulations (for example, 500 mg amoxicillin with 125 mg clavulanic acid, and 875 mg/125 mg) and in intravenous form for hospital use.

Indications include infections where beta-lactamase–producing organisms are suspected or where amoxicillin alone may be ineffective. Common uses are acute otitis media, sinusitis, community-acquired pneumonia, bronchitis with bacterial involvement, skin and soft tissue infections, urinary tract infections, and some dental and intra-abdominal infections. Dosing is determined by infection type, patient age, and renal function.

Mechanism and pharmacokinetics: amoxicillin inhibits bacterial cell wall synthesis; clavulanic acid inhibits beta-lactamases, restoring activity against resistant organisms. The combination is well absorbed when taken by mouth; peak concentrations are achieved within a couple of hours, and the drug is mainly excreted by the kidneys. Dosing intervals commonly range from 8 to 12 hours, depending on the formulation and severity of infection.

Adverse effects are usually mild and include diarrhea, nausea, vomiting, and skin rashes. Serious allergic reactions are rare but possible. Clostridioides difficile infection can occur with broad-spectrum antibiotics. Drug interactions may occur with anticoagulants, methotrexate, and, in some cases, hormonal contraceptives. It should be used with caution in patients with a history of penicillin allergy and in those with significant liver disease.

Contraindications include known hypersensitivity to penicillins or to any component of the product. Pregnancy and lactation: generally considered acceptable when clearly indicated, but use should follow clinical judgment and guidelines. Antibiotic stewardship recommends reserving co-amoxiclav for infections where its broader spectrum is needed to reduce resistance risk.