Flagyl Injection Dosage
Generic name: METRONIDAZOLE 500mg in 100mL
Dosage form: injection, solution
- Flagyl tablet, film coated
- Flagyl 375 Capsules capsule
- Flagyl ER tablet, film coated, extended release
Medically reviewed by Drugs.com. Last updated on Jul 27, 2020.
In elderly patients the pharmacokinetics of metronidazole may be altered and therefore monitoring of serum levels may be necessary to adjust the metronidazole dosage accordingly.
Treatment of Anaerobic Infections
The recommended dosage schedule for adults is:
|Loading Dose||15 mg/kg infused over one hour (approximately 1 g for a 70-kg adult).|
|Maintenance Dose||7.5 mg/kg infused over one hour every six hours (approximately 500 mg for a 70-kg adult). The first maintenance dose should be instituted six hours following the initiation of the loading dose.|
Parenteral therapy may be changed to oral metronidazole when conditions warrant, based upon the severity of the disease and the response of the patient to Metronidazole Injection, USP RTU treatment. The usual adult oral dosage is 7.5 mg/kg every six hours.
A maximum of 4 g should not be exceeded during a 24-hour period.
Patients with severe hepatic disease metabolize metronidazole slowly, with resultant accumulation of metronidazole and its metabolites in the plasma. Accordingly, for such patients, doses below those usually recommended should be administered cautiously. Close monitoring of plasma metronidazole levels3 and toxicity is recommended.
In patients receiving Metronidazole Injection, USP RTU in whom gastric secretions are continuously removed by nasogastric aspiration, sufficient metronidazole may be removed in the aspirate to cause a reduction in serum levels.
The dose of Metronidazole Injection, USP RTU should not be specifically reduced in anuric patients since accumulated metabolites may be rapidly removed by dialysis.
The usual duration of therapy is 7 to 10 days; however, infections of the bone and joint, lower respiratory tract and endocardium may require longer treatment.
For surgical prophylactic use, to prevent postoperative infection in contaminated or potentially contaminated colorectal surgery, the recommended dosage schedule for adults is:
- 15 mg/kg infused over 30 to 60 minutes and completed approximately one hour before surgery; followed by
- 7.5 mg/kg infused over 30 to 60 minutes at 6 and 12 hours after the initial dose.
It is important that (1) administration of the initial preoperative dose be completed approximately one hour before surgery so that adequate drug levels are present in the serum and tissues at the time of initial incision, and (2) Metronidazole Injection, USP RTU be administered, if necessary, at 6-hour intervals to maintain effective drug levels. Prophylactic use of Metronidazole Injection, USP RTU should be limited to the day of surgery only, following the above guidelines.
Caution: Metronidazole Injection, USP RTU is to be administered by slow intravenous drip infusion only, either as a continuous or intermittent infusion. Additives should not be introduced into Metronidazole Injection, USP RTU. If used with a primary intravenous fluid system, the primary solution should be discontinued during metronidazole infusion. DO NOT USE EQUIPMENT CONTAINING ALUMINUM (e.g., NEEDLES, CANNULAE) THAT WOULD COME IN CONTACT WITH THE DRUG SOLUTION.
Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit.
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.
Frequently Asked Questions
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More about Flagyl IV (metronidazole)
- Side Effects
- During Pregnancy or Breastfeeding
- Drug Interactions
- 2 Reviews
- Drug class: amebicides
- FDA Alerts (3)
Other brands: Flagyl ER