Metronidazole 0.75–0.8% Gel (Topical)

How it works

Within anaerobic bacteria its nitro group is reduced to reactive intermediates that damage microbial DNA, suppressing the anaerobes responsible for wound odour.

Prescribing in practice

• It controls odour and surface anaerobic colonisation but is not a substitute for systemic antibiotics in invasive wound infection or burns sepsis, which need parenteral treatment.
• Apply to clean wound beds and cover with a non-adherent dressing; the gel is for cutaneous use and should be kept away from the eyes.
• Systemic absorption from intact-bordered wounds is low, so the disulfiram-like alcohol reaction is far less likely than with oral therapy, but caution remains over large denuded areas.

Monitoring

Monitor wound odour, surface appearance and the periwound skin for irritation, escalating to systemic assessment if signs of spreading or invasive infection develop.

Counselling the patient

• This gel is mainly to reduce wound smell and surface germs, not to treat a deep infection.
• Report increasing redness, pain, fever or spreading around the wound promptly.
• Avoid getting the gel in the eyes and follow the dressing routine shown by the team.

Evidence & guidelines

Topical metronidazole for malodorous wounds is supported by palliative wound-care guidance and longstanding clinical practice rather than large burns-specific trials.