Antimicrobials
Metronidazole

Metronidazole

Low
Excellent
See below under General Info

Spectrum of Activity

Dosing

General Information

Hospital Formulary Status Yes (PO solid, parenteral inj)

In-Hospital Cost will be updated

PharmaCare Formulary Status Yes (PO solid, parenteral inj, cream, gel, powder)

Special Authority None

PharmaCare Coverage 250mg PO - $0.0710/tab 500mg PO - $0.5917/cap Pfizer 500mg/0.1L liquid for inj - $0.187812/ml Baxter 500mg/0.1L liquid for inj - $0.0296/ml Powder (topical use) - $0.7500/g 1% cream - $0.7223/g 1% gel - $0.7291/g
0.75% vaginal gel - $0.3356/g 10% vaginal cream - $0.2763/g

Outpatient Cost 250mg PO - $0.07-0.23/tab 500mg PO - $0.59-0.69/cap Pfizer 500mg/0.1L liquid for inj - $0.19-0.21/ml Baxter 500mg/0.1L liquid for inj - $0.03-0.04/ml Powder (topical use) - $0.43-0.47/g 1% cream - $0.72-0.79/g 1% gel - $0.73-0.80/g 0.75% vaginal gel - $0.34-0.37/g 10% vaginal cream - $0.28-0.30/g

Suspected or confirmed anaerobic infections including:

  •  Intra-abdominal
  •  Biliary
  •  Central nervous system
  •  Clostridium difficile
  •  Giardia
  •  Pelvic infections

Also used in:

  •  Crohns disease
  •  Bacterial vaginosis
  •  Hepatic encephalopathy

With prolonged therapy (>6wks) or if symptoms develop assess for peripheral/optic neuropathy

Gastrointestinal (PO and IV)

  •  common sx: metallic taste, nausea, vomiting, diarrhea, anorexia, abdominal cramping and constipation
  •  uncommon sx: furry tongue, glossitis and stomatitis (associated with candidal overgrowth)

Neurotoxicity (mainly with IV)

  •  sx: seizures, peripheral neuropathy, dizziness, vertigo, ataxia, confusion, encephalopathy, irritability, weakness, insomnia, headache and tremors
  •  can occur at high cumulative doses of >40g
  •  may be visualized on MRI (bilateral symmetric T2 hyperintense lesions)
  •  lesions and sx may resolve within 3–7 days of discontinuation

Allergic reactions (PO and IV)

  •  sx: urticaria, erythematous rash, SOB, edema, flushing, bronchospasm and serum sickness
  •  can occur within 60 mins of the first dose
  •  possible treatment: methylprednisolone and diphenhydramine
  •  sx may resolve within 5 days

Genitourinary (PO, IV and PV)

  •  common sx: transient darkening of the urine (deep red-brown color) and vaginitis (PV)
  •  uncommon sx: dysuria, cystitis, incontinence, vaginal Candida overgrowth and decreased libido

Disulfiram-like reactions (PO, IV and PV)

  •  can occur when administered systemically or vaginally to patients drinking ethanol
  •  sx: flushing, sweating, headache, tachycardia, palpitations, nausea, vomiting, dyspnea, skin pallor and acidosis
  •  may be caused by an increase in intracolonic acetaldehyde concentrations and metronidazole's impact on intestinal flora, with conversion to alcohol dehydrogenase-containing anaerobes
  •  avoid alcohol ingestion during metronidazole therapy and for at least 48 hours after discontinuation

Other

  •  joint pain
  •  thrombophlebitis
  •  reversible neutropenia
  •  thrombocytopenia
  •  pancreatitis
  •  hepatitis
  •  QT interval prolongation

Ethanol - Disulfiram-like reaction

Increases levels of:

  •  Cyclosporine
  •  Lithium
  •  Warfarin
  •  Phenobarbital
  •  Phenytoin

Antimicrobial class: Nitroimidazole

Pregnancy category: B

Bacterial, protozoal and ameobic DNA is fragmented by reactive nitroso-imidazole radicals

Average serum half life: 10.0 hr

Biliary penetration: Therapeutic

CSF penetration: Therapeutic

Lung penetration: Therapeutic

Urine penetration: Poor