IV Dilution &
Medication Reference

TOBRAMYCIN

Usual Diluents

Standard Dilutions [Amount of drug] [Infusion volume] [Infusion rate]

[> 40 mg] [100 ml] [30-60 min]

Stability / Miscellaneous

Reconstituted powder for injection: After reconstitution, the solution should be kept in a refrigerator and used within 96 hours. If kept at room temperature, the solution must be used within 24 hours.

Label: Refrigerate.

DOSAGE AND ADMINISTRATION
Tobramycin injection may be given intramuscularly or intravenously. Recommended dosages are the same for both routes. The patient's pretreatment body weight should be obtained for calculation of correct dosage. It is desirable to measure both peak and trough serum concentrations (see package insert for WARNINGS box and PRECAUTIONS).

Administration for Patients with Normal Renal Function
Adults with Serious Infections: 3 mg/kg/day in 3 equal doses every 8 hours (see Table 1).

Adults with Life-Threatening Infections: Up to 5 mg/kg/day may be administered in 3 or 4 equal doses (see Table 1). The dosage should be reduced to 3 mg/kg/day as soon as clinically indicated. To prevent increased toxicity due to excessive blood levels, dosage should not exceed 5 mg/kg/day unless serum levels are monitored.
TABLE 1: DOSAGE SCHEDULE GUIDE FOR TOBRAMYCIN SULFATE IN ADULTS WITH NORMAL RENAL FUNCTION (Dosage at 8-Hour Intervals)

Children: 6 to 7.5 mg/kg/day in 3 or 4 equally divided doses (2 to 2.5 mg/kg every 8 hours or 1.5 to 1.89 mg/kg every 6 hours).

It is desirable to limit treatment to a short term. The usual duration of treatment is 7 to 10 days. A longer course of therapy may be necessary in difficult and complicated infections. In such cases, monitoring of renal, auditory, and vestibular functions is advised, because neurotoxicity is more likely to occur when treatment is extended longer than ten days.

Administration for Patients with Impaired Renal Function
Whenever possible, serum tobramycin concentrations should be monitored during therapy.

Following a loading dose of 1 mg/kg, subsequent dosage in these patients must be adjusted, either with reduced doses administered at 8-hour intervals or with normal doses given at prolonged intervals. Both of these methods are suggested as guides to be used when serum levels of tobramycin cannot be measured directly. They are based on either the creatinine clearance level or the serum creatinine of the patient, because these values correlate with the half-life of tobramycin. The dosage schedules derived from either method should be used in conjunction with careful clinical and laboratory observations of the patient and should be modified as necessary. Neither method should be used when dialysis is being performed.

Reduced dosage at 8-hour intervals

When the creatinine clearance rate is 70 mL or less per minute or when the serum creatinine value is known, the amount of the reduced dose can be determined by multiplying the normal dose from Table 1 by the percent of normal dose from the accompanying nomogram.

An alternate rough guide for determining reduced dosage at 8-hour intervals (for patients whose steady-state serum creatinine values are known) is to divide the normally recommended dose by the patient's serum creatinine.

Normal dosage at prolonged intervals

If the creatinine clearance rate is not available and the patient's condition is stable, a dosage frequency in hours for the dosage given in Table 1 can be determined by multiplying the patient's serum creatinine by 6.

Alternatively: Dosing interval in renal impairment: I.M., I.V.:
Conventional dosing:
Clcr 60 mL/minute: Administer every 8 hours
Clcr 40-60 mL/minute: Administer every 12 hours
Clcr 20-40 mL/minute: Administer every 24 hours
Clcr 10-20 mL/minute: Administer every 48 hours
Clcr<10 mL/minute: Administer every 72 hours

High-dose therapy: Interval may be extended (eg, every 48 hours) in patients with moderate renal impairment (Clcr 30-59 mL/minute) and/or adjusted based on serum level determinations.

Hemodialysis: Dialyzable; 30% removal of aminoglycosides occurs during 4 hours of HD - administer dose after dialysis and follow levels

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Dosage in Obese Patients
The appropriate dose may be calculated by using the patient's estimated lean body weight plus 40% of the excess as the basic weight on which to figure mg/kg.

Intramuscular Administration
Tobramycin sulfate may be administered by withdrawing the appropriate dose directly from a vial or by using a prefilled disposable syringe.

Intravenous Administration
Must dilute for IV use. For intravenous administration, the usual volume of diluent (0.9% Sodium Chloride Injection or 5% Dextrose Injection) is 50 to 100 mL for adult doses. For children, the volume of diluent should be proportionately less than for adults. The diluted solution usually should be infused over a period of 20 to 60 minutes. Infusion periods of less than 20 minutes are not recommended, because peak serum levels may exceed 12 µg/mL.

Tobramycin sulfate should not be physically premixed with other drugs but should be administered separately according to the recommended dose and route.

Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration whenever solution and container permit.

HOW SUPPLIED
Tobramycin injection is available as:
40 mg/mL
2 mL vials packed in 25s NDC 0003-2725-10
30 mL Multi Dose Vials (80 mg/2mL) individually packed NDC 0003-2725-30

Storage
Store at controlled room temperature 15°-30° C (59°-86° F).

APOTHECON®
Manufactured by
Bristol-Myers Squibb Company
Princeton, NJ 08543 USA
Distributed by
Geneva Pharmaceuticals, Inc.
Dayton, NJ 08810 USA

1135942
Revised September 2001

Source: [package insert]