Standard: 500 mg IV/PO q8 - 12h
(metronidazole is 100% bioavailable - use oral metronidazole in all patients with a functioning GI system that are able to tolerate oral medications)
Clostridium difficile and central nervous system infections: 500 mg PO/IV q8h
500 mg po BID x 7 days
Preferred: (use this dose in HIV positive patients)Alternative:500 mg po BID x 7 days2 g po x 1 dose
500 mg po TID x 48 hours (in combination with cephalexin 500 mg po TID)
Infuse over 60 minutes
Age 0-4 WkLoading dose 15 mg/kg IV, then 7.5 mg/kg/dose IV Q48H
Age 0-7 DaysAge >7 DaysLoading dose 15 mg/kg IV, then 7.5 mg/kg/dose IV Q24HLoading dose 15 mg/kg IV, then 7.5 mg/kg/dose IV Q12H
Age 0-7 DaysAge > 7 DaysLoading dose 15 mg/kg IV, then 7.5 mg/kg/dose IV Q12H15 mg/kg/dose IV Q12H
15 mg/kg/dose IV Q12H
IV, PO
5 mg/mL
Supplied by pharmacy
5 mg/mL = 24H (after first use)
Room Temperature
Consider dose reduction with severe hepatic impairment (Child-Pugh C)
Reduce dose in liver impairment
Suspected or confirmed anaerobic infections including intra-abdominal, biliary, central nervous system, Clostridium difficile, Giardia and pelvic infections.
Also used in Crohns disease, bacterial vaginosis, trichomoniasis, and hepatic encephalopathy
Used in combination therapy with a beta-lactam for chorioamniotitis and endometritis.
Pregnancy:
Metronidazole crosses the placenta. Studies have not shown an increased risk of congenital anomalies or other adverse events to the fetus following maternal use during pregnancy
Because metronidazole was carcinogenic in some animal species, concern has been raised whether metronidazole should be used during pregnancy, however, available studies have not shown an increased risk of cancer following human exposure or infant cancer following metronidazole exposure during pregnancy
Metronidazole is considered compatible during pregnancy
Breastfeeding:
The relative infant dose (RID) of metronidazole has been reported as high as 24%
Both metronidazole and its active metabolite are detectable in infant serum after exposure via breastmilk, however, exposure via breasmilk is significantly lower compared to neonates that are given therapeutic doses of metronidazole
There are some case reports of infant diarrhea via breastmilk exposure
Metronidazole is considered compatible with breastfeeding and holding breastfeeding following metronidazole doses (including the 2 g dose) is not necessary
Monitor the infant for signs of gastrointestinal intolerance.
With prolonged therapy (> 6 wks) or if symptoms develop assess for peripheral/optic neuropathy
GI symptoms common - especially nausea/vomiting and metallic taste
Peripheral/optic neuropathy with extended therapy
Disulfiram-like reaction with alcohol (severe vomiting)
Rare neurotoxicity including aseptic meningitis and encephalopathy
Luekopenia, neutropenia
Ethanol - disulfiram like reaction
Increases levels of cyclosporine, lithium, warfarin, and phenobarbital and phenytoin
