Metronidazole (Paediatric)

How it works

Within susceptible anaerobic bacteria and protozoa it is reduced to reactive intermediates that damage microbial DNA, leading to cell death.

Prescribing in practice

• The most important paediatric counselling point is that alcohol (including in liquid medicines and some mouthwashes) must be avoided during and shortly after treatment because of a disulfiram-like reaction.
• Prolonged or repeated courses carry a risk of peripheral and central neurotoxicity, so duration should be limited and the indication reviewed.
• Dose is weight-based and available by oral, intravenous and rectal routes; doses should be confirmed against a children's formulary, with caution in hepatic impairment.

Monitoring

Monitor for neurological symptoms (numbness, tingling, ataxia) and hepatic function on prolonged courses, alongside clinical response.

Counselling the patient

• Avoid all alcohol during the course and for a short period afterwards to prevent flushing, nausea and palpitations.
• Report any numbness, tingling, unsteadiness or persistent headache.
• Complete the full course as prescribed even if the child feels better.

Evidence & guidelines

Metronidazole is a long-established first-line agent for anaerobic and several protozoal infections, with its alcohol interaction and neurotoxicity risk well documented.