Metronidazole
BASICS: DOSAGE:
• Antimicrobial medicine • Oral: 400mg every 8 hours (t.d.s.) or
500mg every 8 hours (t.d.s.) for 7 days
• Prevention of post-operative infections
• IV infusion: 500mg every 8 hours for 7
• Treatment of septicaemia, cellulitis, wound
days, given over 20 minutes
infections etc.
• Surgical prophylaxis: 400-500mg to be ad-
• Tablets or solution for injection or IV
ministered 2 hours before surgery, then
infusion
400-500mg every 8 hours if required for
• POM
24 hours.
SIDE EFFECTS: INTERACTIONS:
• Dry mouth, myalgia, nausea, metallic taste • Disulfiram - acute psychosis + confusion
in mouth, vomiting, headache
• Phenobarbital + phenytoin - increased
metabolism
CONTRAINDICATIONS: • Anticoagulants - increases effect
• If topical cream used - avoid exposure to • Contraceptives - reduce effect
strong sunlight or UV light
• Hypersensitivity
PHARMACODYNAMICS: FETAL/BREASTFEEDING RISK:
• Antimicrobial agent acting on wide range • Avoid high dose regimes - 1st trimester
of anaerobic bacteria and protozoa use could lead to congenital
malformations e.g. limb defects
• Absorbed in the GI tract - peak plasma
concentration is 20 mins to 3 hours • Should only be given if essential as
insufficient evidence on safety in
• Excreted in the urine via the kidneys
pregnancy and lactation
• Excreted in breastmilk however amount
thought to be less than the therapeutic
dose for infant
BASICS: DOSAGE:
• Antimicrobial medicine • Oral: 400mg every 8 hours (t.d.s.) or
500mg every 8 hours (t.d.s.) for 7 days
• Prevention of post-operative infections
• IV infusion: 500mg every 8 hours for 7
• Treatment of septicaemia, cellulitis, wound
days, given over 20 minutes
infections etc.
• Surgical prophylaxis: 400-500mg to be ad-
• Tablets or solution for injection or IV
ministered 2 hours before surgery, then
infusion
400-500mg every 8 hours if required for
• POM
24 hours.
SIDE EFFECTS: INTERACTIONS:
• Dry mouth, myalgia, nausea, metallic taste • Disulfiram - acute psychosis + confusion
in mouth, vomiting, headache
• Phenobarbital + phenytoin - increased
metabolism
CONTRAINDICATIONS: • Anticoagulants - increases effect
• If topical cream used - avoid exposure to • Contraceptives - reduce effect
strong sunlight or UV light
• Hypersensitivity
PHARMACODYNAMICS: FETAL/BREASTFEEDING RISK:
• Antimicrobial agent acting on wide range • Avoid high dose regimes - 1st trimester
of anaerobic bacteria and protozoa use could lead to congenital
malformations e.g. limb defects
• Absorbed in the GI tract - peak plasma
concentration is 20 mins to 3 hours • Should only be given if essential as
insufficient evidence on safety in
• Excreted in the urine via the kidneys
pregnancy and lactation
• Excreted in breastmilk however amount
thought to be less than the therapeutic
dose for infant
