(METRONIDAZOLE BP 0.5% 10/V)

COMPOSITION:

Metrodine® Intravenous Infusion contains 500mg metronidazole in 100ml solution.

CLINICAL PHARMACOLOGY:

Metronidazole has antiprotozoal and antibacterial actions and is effective against Trichomonas Vaginalis and other protozoa including Entamoeba histolytica and Gardia lambila and against anaerobic bacteria.

Widely distributed in therapeutic levels to all body fluids (including abscesses). Levels are directly proportional to dose given. Onset of action is prompt and last about 8 hours. Crosses placental and blood–brain barriers. Excreted in urine, some in faeces. Secreted in breast milk.

INDICATIONS:

  • The prevention of post-operative infections due to anaerobic bacteria, particularly species of Bacteroides and anaerobic Streptococci.
  • The treatment of septicaemia, bacteraemia, Peritonitis, brain abscess, necrotising pneumonia, Osteomyelitis, Pueperal Sepsis, Pelvic abscess, Pelvic Cellulitis and post-operative wound infections from which Pathogenic Anaerobes have been isolated.

CONTRAINDICATIONS:

Hypersensitivity to metronidazole or Nitroimidazole derivatives; first trimester of pregnancy.

INTERACTIONS:

  • Patients should be advised to avoid alcohol, alcohol containing preparations for at least 3days after taking any dose of Metronidazole because of the possibility of a dissulfiram – like (antabuse effect) reaction.
  • Patients receiving Phenobarbitone metabolise Metronidazole at a much greater rate than normal, reducing the half – life to approximately 3 hours.
  • Bactericidal action of Metronidazole may be negated by bacteriostatic antibiotics (e.g. Chloramphenicol, Erythromycin and tetracyclines).
  • Cimetidine may increase Metronidazole serum levels.
  • Metronidazole may decrease metabolism and increase anticoagulant effects of warfarin.
  • Metronidazole may increase Lithium levels and cause toxicity.

WARNINGS/PRECAUTIONS:

  • In patients undergoing Haemodialysis, Metronidazole and Metabolites are efficiently removed during an eight hour period of dialysis. Metronidazole should therefore be re-administered immediately after haemodialysis.
  • Metronidazole should be used with caution in patients with active disease of the Central Nervous System.
  • Metronidazole infusion may be diluted with appropriate volumes of normal saline, dextrose–saline, dextrose 5%w/v or Potassium Chloride Infusions (20 and 40mmol/litre).

PREGNANCY AND LACTATION:

There is inadequate evidence of the safety of Metronidazole in pregnancy. Metronidazole should not therefore be given during pregnancy or during lactation unless the Physician considers it essential; In these circumstances the short, high-dosage regimens are not recommended.

ADVERSE REACTIONS: Serious adverse reactions occur rarely with standard recommended regimes.

During intensive and/or prolonged Metronidazole therapy a few instances of peripheral neuropathy or transient epileptiform seizures have been reported. In most cases neuropathy disappeared after treatment was stopped or when dosage was reduced.

Drowsiness, dizziness, headaches, ataxia, skin rashes,Pruritus, inco-ordination of movement, darkening of urine (due to Metronidazole Metabolite) Myalgia and arthralgia have been reported but very rarely.

SYMPTOMS OF OVERDOSE AND ANTIDOTE:

Treatment will be symptomatic and supportive.

Discontinue Metronidazole with onset of seizures or signs of peripheral neuropathy (e.g. numbness or paresthesia of an extremity; benefit/risk of therapy must be considered with onset of convulsions or peripheral neuropathy. Rapidly removed by hemodialysis. Treat anaphy laxis and resuscitate as necessary.

DOSAGE AND ADMINISRATION

Adult Dose:

Anaerobic Infections: Begin with an initial loading dose of 15mg/kg of body weight. Follow with 7.5mg/kg (up to g/dose) in 6 hours and every 6 hours thereafter for 7 to 10 days or longer if indicated.

Do not exceed 4g in 24 hours.

Complicated Intra-abdominal infections: 50mg every 6 hours given in combination with ciprofloxacin 400mg every 12 hours.

Prevent Post operative Infection in contaminated or potentially contaminated colorectal surgery: 15mg/kg infused over 30 to 60 minutes and completed 1 hour before surgery. Follow with 7.5mg/kg in 6 hours and in 12 hours. If Bacteroides Fragilis is the suspected or confirmed organism, an alternate regimen is to give a 1,500mg dose at the beginning of Surgery to ensure adequate metronidazole levels.

Amebiasis: 500 to 750mg every 8 hours for 5 to 10 days.

Paediatric Dose:

Safety for use in infants and children not established, but is used for anaerobic infections.

Anaerobic Infections: Children and Infants more than 7 days of age: An initial loading dose of 15mg/kg. Follow with 7.5mg/kg every 6 or 8 hours.

Preterm Infants: An initial loading dose of 15mg/kg. 48 hours after loading dose begin 7.5mg/kg every 12 hours.

Term Infants: Same as preterm except begin maintenance dose (7.5mg/kg) 24 hours after loading dose.

Dose Adjustment:

Reduce dose in hepatic disease and in the elderly. Increase intervals in neonates.

List of excipients:

Metrodine Infusion also contains Sodium Chloride 0.9% and water for Injection.

Presentation: Metrodine® Infusion is available as 0.5%w/v Metronidazole in 100ml bag.

Storage: Store at room temperature.