Co-amoxiclav

How it works

Amoxicillin inhibits bacterial cell-wall synthesis while clavulanic acid protects it from beta-lactamase enzymes, broadening cover to include many resistant Gram-negative and anaerobic organisms.

Prescribing in practice

• Avoid in patients with penicillin allergy, and note co-amoxiclav carries a higher risk of cholestatic jaundice and hepatitis than amoxicillin alone, particularly with prolonged courses.
• Maternal use around the time of very preterm delivery has been associated with neonatal necrotising enterocolitis, so it is generally avoided for preterm prelabour rupture of membranes.
• Adjust dosing in significant renal impairment and review the need for continued treatment regularly.

Monitoring

Routine monitoring is not required for short courses, but check liver function with prolonged treatment and review clinical and microbiological response.

Counselling the patient

• Take with food to reduce stomach upset.
• Report yellowing of the skin or eyes, dark urine or severe diarrhoea.
• Complete the prescribed course and seek urgent help for any allergic reaction.

Evidence & guidelines

Co-amoxiclav is a standard broad-spectrum option for mixed infections; its avoidance in preterm prelabour rupture of membranes follows the ORACLE trial findings on neonatal necrotising enterocolitis.