metronidazole benzoate: clinical use

Prescribing considerations

• Confirm that the suspected organism and infection site are appropriate for metronidazole and follow applicable antimicrobial guidance.
• Review hepatic impairment, neurological disease, dialysis, pregnancy, breastfeeding and clinically important interacting medicines.
• Consider the suspension's sucrose, sorbitol, propylene glycol and parahydroxybenzoate content, particularly in young children and people with relevant metabolic disorders.
• Avoid unnecessarily prolonged exposure because neurological toxicity becomes more important with intensive or extended treatment.

Contraindications and cautions

• Hypersensitivity to metronidazole, another nitroimidazole, hydroxybenzoates or any formulation excipient.
• Hereditary fructose intolerance because the selected formulation contains sorbitol.
• Fructose intolerance, glucose-galactose malabsorption or sucrase-isomaltase insufficiency because the selected formulation contains sucrose.

Monitoring

• For extended treatment, undertake clinical review and consider leucocyte monitoring; assess promptly for peripheral or central neurological toxicity.
• Advanced hepatic impairment may substantially reduce clearance; monitor clinically and review exposure.
• In Cockayne syndrome, use only after careful benefit-risk assessment when no alternative is available, with liver-function monitoring before, during and after treatment.
• Apply interaction-specific monitoring, including coagulation with warfarin, lithium and renal indices, or calcineurin-inhibitor levels and creatinine.

Clinical pharmacology

Metronidazole is readily absorbed orally, distributes widely—including into cerebrospinal fluid and breast milk—and undergoes mainly hepatic metabolism. Reduction of its nitro group in susceptible anaerobic organisms produces reactive intermediates that disrupt DNA structure and synthesis.

Formulation and product differences

• The selected product is an oral suspension containing metronidazole benzoate equivalent to metronidazole.
• It is sweetened and lemon-orange flavoured and contains sucrose, sorbitol, propylene glycol and methyl parahydroxybenzoate.
• Shake well before administration and use an oral dosing device for accurate measurement.
• Store in the original package protected from light and discard unused suspension 14 days after opening.

Oral suspension

Route: Oral

Strengths: 200 mg/5 mL