Adult Dosing
Anaerobic infections
- Loading dose: 15 mg/kg slow IV over 1 hr
- Maintenance dose: 7.5 mg/kg slow IV over 1 hr q6 hrs
- Max: 1 g/dose; 4 g/day
Perioperative prophylaxis
- 15 mg/kg slow IV 1 hr prior to surgery; then 7.5 mg/kg slow IV at 6 and 12 hrs after the initial dose
Note: Metronidazole injection should be administered by slow IV only, either as a continuous or intermittent infusion
Tetanus [Non-FDA Approved]
- 1 gm IV loading dose, followed by 500 mg q6 hrs
Pediatric Dosing
- Safety and effectiveness in pediatric patients have not been established
Tetanus [Non-FDA Approved]
- <7 days:
- <1.2 kg: 7.5 mg/kg/dose q48 hr
- 1.2-2 kg: 7.5 mg/kg/dose q24 hr
2 kg: 15 mg/kg/24 hr divided q12 hr
- 7 days:
- <1.2 kg: 7.5 mg/kg/dose q24 hr
- 1.2-2 kg: 15 mg/kg/24 hr divided q12 hr
- 2 kg: 30 mg/kg/24 hr divided q12 hr
- Infant/child:
- 30 mg/kg/24 hr divided q6 hr
- Max. dose: 4 g/24 hr
Cellulitis/Orbital cellulitis [Non-FDA Approved]
- <7 days:
- <1.2 kg: 7.5 mg/kg/dose q48 hr
- 1.2-2 kg: 7.5 mg/kg/dose q24 hr
- 2 kg: 15 mg/kg/24 hr divided q12 hr
- 7 days:
- <1.2 kg: 7.5 mg/kg/dose q24 hr
- 1.2-2 kg: 15 mg/kg/24 hr divided q12 hr
- 2 kg: 30 mg/kg/24 hr divided q12 hr
- Infant/child:
- 30 mg/kg/24 hr divided q6 hr
- Max. dose: 4 g/24 hr
- Metronidazole has been shown to be carcinogenic in mice and rats. Reserve use for approved conditions [US Black Box Warning]
- Convulsive seizures and peripheral neuropathy have been reported in patients treated with metronidazole; evaluate promptly if neurological signs develop and weigh risk/benefit ratio
- Mild leukopenia has been observed during administration of metronidazole
- Decrease infant exposure by withholding breastfeeding for 12-24 hrs after maternal single dose
- Monitor serum creatinine at baseline; WBC with differential count at baseline and after completion of therapy
Cautions: Use cautiously in
- Severe hepatic impairment
- Hx of blood dyscrasias
- Hx of seizures or neurologic problems
- Patients receiving corticosteroids
Pregnancy Category:B
Breastfeeding: Metronidazole is excreted in breastmilk. With maternal intravenous and oral therapy, breastfed infants receive metronidazole in doses that are less than those used to treat infections in infants. Candidal infections and diarrhea have been reported in breastfed infants. Oral and rectal colonization might be more common in infants exposed to metronidazole. This information is based upon LactMed database (available at http://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?LACT last accessed 11 February 2011). Due to the potential for serious adverse reactions in nursing infants, manufacturer recommends discontinuation of nursing or discontinuation of drug, taking into account the importance of the drug to the mother.
