RECOMMENDED DOSAGE FOR THE TREATMENT OF ANAEROBIC BACTERIAL INFECTIONS
The recommended dosage schedule for
adults for the treatment of anaerobic infections is presented in Table 1:
Table 1: Recommended Dosage Schedule for the Treatment of Anaerobic Bacterial Infections in Adults
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 therapy when conditions warrant, based upon the severity of the disease and the response of the patient to treatment with Metronidazole Injection. The usual adult oral dosage is 7.5 mg/kg every six hours.
A maximum of 4 grams should not be exceeded during a 24-hour period.
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.
Recommended Dosage for the Treatment of Intra-Abdominal Infections in Pediatric Patients Less than 4 Months of Age:
The recommended dosage schedule for
pediatric patients less than 4 months of age for the treatment of intra-abdominal infections is described in Table 2 below.
These dosage schedules achieve drug exposures in pediatric patients similar to adults treated with Metronidazole Injection for this indication.
Table 2: Recommended Dosage Schedule for the Treatment of Intra-Abdominal Infections in Pediatric Patients Less than 4 months of Age
Post-menstrual age (Completed weeks) | Loading Dose (mg/kg) | Maintenance Dose* (mg/kg) | Dosing interval (hours) |
23 to <34 | 15 | 7.5 | 12 |
34 to 40 | 15 | 7.5 | 8 |
>40 to 48 | 15 | 7.5 | 6 |
*The first maintenance dose is given 24 hours after the start of the loading dose.
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 levels and toxicity is recommended.
1
In patients receiving Metronidazole Injection 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 should not be specifically reduced in anuric patients since accumulated metabolites may be rapidly removed by dialysis.
Dosage Considerations in Geriatric Patients
In elderly patients the pharmacokinetics of metronidazole may be altered and, therefore, monitoring of serum levels may be necessary to adjust the Metronidazole Injection dosage accordingly.
RECOMMENDED PROPHYLAXIS DOSAGE
For surgical prophylactic use, to prevent postoperative infection in contaminated or potentially contaminated colorectal surgery, the recommended dosage schedule for adults is:
a. 15 mg/kg infused over 30 to 60 minutes and completed approximately one hour before surgery, followed by:
b. 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 be administered, if necessary, at 6-hour intervals to maintain effective drug levels. Prophylactic use of Metronidazole Injection should be limited to the day of surgery only, following the above guidelines.
IMPORTANT PREPARATION AND ADMINISTRATION INSTRUCTIONS
Caution: Metronidazole Injection - is to be administered by slow intravenous drip infusion only, either as a continuous or intermittent infusion. IV admixtures containing metronidazole and other drugs should be avoided. Additives should not be introduced into this solution. 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.
Metronidazole Injection is a ready-to-use isotonic solution.
NO DILUTION OR BUFFERING IS REQUIRED. Do not refrigerate. Each container of Metronidazole Injection contains 13.5 mEq of sodium.
Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit. Do not use if cloudy or precipitated or if the seals are not intact.
Use sterile equipment. It is recommended that the intravenous administration apparatus be replaced at least once every 24 hours.