Tobramycin
Dosing in kidney impairment
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.
This dosing regimen is suggested only as a guide. The serum levels of tobramycin should be measured directly during treatment due to a wide interpatient variability. 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 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.
| For Patient Weighing | Usual Dose for Serious Infections | Maximum Dose for Life- Threatening Infections (Reduce as soon as possible) | |||
| 1 mg/kg q8h (Total, 3 mg/kg/day) | 1.66 mg/kg q8h (Total, 5 mg/kg/day) | ||||
| mg/dose | mL/dose* | mg/dose | mL/dose* | ||
| kg | lb | q8h | q8h | ||
| 120 | 264 | 120 mg | 3 mL | 200 mg | 5 mL |
| 115 | 253 | 115 mg | 2.9 mL | 191 mg | 4.75 mL |
| 110 | 242 | 110 mg | 2.75 mL | 183 mg | 4.5 mL |
| 105 | 231 | 105 mg | 2.6 mL | 175 mg | 4.4 mL |
| 100 | 220 | 100 mg | 2.5 mL | 166 mg | 4.2 mL |
| 95 | 209 | 95 mg | 2.4 mL | 158 mg | 4 mL |
| 90 | 198 | 90 mg | 2.25 mL | 150 mg | 3.75 mL |
| 85 | 187 | 85 mg | 2.1 mL | 141 mg | 3.5 mL |
| 80 | 176 | 80 mg | 2 mL | 133 mg | 3.3 mL |
| 75 | 165 | 75 mg | 1.9 mL | 125 mg | 3.1 mL |
| 70 | 154 | 70 mg | 1.75 mL | 116 mg | 2.9 mL |
| 65 | 143 | 65 mg | 1.6 mL | 108 mg | 2.7 mL |
| 60 | 132 | 60 mg | 1.5 mL | 100 mg | 2.5 mL |
| 55 | 121 | 55 mg | 1.4 mL | 91 mg | 2.25 mL |
| 50 | 110 | 50 mg | 1.25 mL | 83 mg | 2.1 mL |
| 45 | 99 | 45 mg | 1.1 mL | 75 mg | 1.9 mL |
| 40 | 88 | 40 mg | 1 mL | 66 mg | 1.6 mL |
| * Applicable to all product forms except Tobramycin Injection, USP, 10 mg/mL (Pediatric). | |||||
Preparation and administration
Intravenous Administration 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 pediatric patients, 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 mcg/mL (see WARNINGS box). Tobramycin Injection, USP 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. graphic reduced dosage nomogram