Kanamycin dosage and administration

# Dosage and Administration
Kanamycin injection may be given intramuscularly or intravenously.  The patients pretreatment body weight should be obtained for calculation of the correct dosage.  The dosage of an aminoglycoside in obese patients should be based on an estimate of the lean body mass.  The status of renal function should be determined by measurement of serum creatinine concentration or calculation of the endogenous creatinine clearance rate.  The blood urea nitrogen (BUN) level is much less reliable for this purpose.  Renal function should be reassessed frequently during therapy.
It is desirable to measure both peak and trough serum concentrations intermittently during therapy since both concentrations are used to determine the adequacy and safety of the dose and to adjust the dosage during treatment.  Peak serum concentrations (30 to 90 minutes after injection) above 35 mcg per mL and trough concentrations (just prior to the next dose) above 10 mcg per mL should be avoided.

### Intramuscular Route
Inject deeply into the upper outer quadrant of the gluteal muscle.  The recommended dose for adults or children is 15 mg/kg/day in two equally divided dosages administered at equally divided intervals; i.e., 7.5 mg/kg q12h.  If continuously high blood levels are desired, the daily dose of 15 mg/kg may be given in equally divided doses every 6 or 8 hours.  Treatment of patients in the heavier weight classes, i.e., 100 kg, should not exceed 1.5 g/day.
In patients with impaired renal function, it is desirable to follow therapy by appropriate serum assays.  If this is not feasible, a suggested method is to reduce the frequency of administration in patients with renal dysfunction.  The interval between doses may be calculated with the following formula:
Serum creatinine (mg/100 mL) x 9 = Dosage Interval (in hours); e.g., if the serum creatinine is 2 mg, the recommended dose (7.5 mg/kg) should be administered every 18 hours.
Changes in creatinine concentration during therapy would, of course, necessitate changes in the dosage frequency.
It is desirable to limit the duration of treatment with kanamycin to short-term.  The usual duration of treatment is 7 to 10 days.  Total daily dose by all routes of administration should not exceed 1.5 g/day.  If longer therapy is required, measurement of kanamycin peak and trough serum concentrations is particularly important as a basis for determining the adequacy and safety of the dose.  These patients should be carefully monitored for changes in renal, auditory, and vestibular function.  Dosage should be adjusted as needed.  The risks of toxicity multiply as the length of treatment increases.
At the recommended dosage level, uncomplicated infections due to kanamycin-susceptible organisms should respond to therapy in 24 to 48 hours.  If definite clinical response does not occur within 3 to 5 days, therapy should be stopped and the antibiotic susceptibility pattern of the invading organism should be rechecked.  Failure of the infection to respond may be due to resistance of the organism or to the presence of septic foci requiring surgical drainage.

### Intravenous Administration
The dose should not exceed 15 mg/kg per day and must be administered slowly.  The solution for intravenous use is prepared by adding the contents of a 500 mg vial to 100 to 200 mL of sterile diluent such as Normal Saline or 5% Dextrose in Water, or the contents of a 1g vial to 200 to 400 mL of sterile diluent.  The appropriate dose is administered over a 30- to 60-minute period.  The total daily dose should be divided into 2 or 3 equally divided doses.
Kanamycin Injection, USP should not be physically mixed with other antibacterial agents but each should be administered separately in accordance with its recommended route of administration and dosage schedule.

### Intraperitoneal Use
(Following exploration for established peritonitis or after peritoneal contamination due to fecal spill during surgery.)
500 mg diluted in 20 mL sterile distilled water may be instilled through a polyethylene catheter sutured into the wound at closure.  If possible, instillation should be postponed until the patient has fully recovered from the effects of anesthesia and muscle-relaxing drugs (see duration of treatment statement above and WARNING box).  Serum levels should be carefully monitored during treatment.
NOTE: The pediatric dosage form 75 mg/2 mL should be used for pediatric patients.

### Aerosol Treatment
250 mg two to four times a day.  Withdraw 250 mg (1mL) from a 500 mg vial and dilute it with 3 mL Physiological Saline and nebulize.  Serum levels should be carefully monitored during treatment.

### Other Routes of Administration
Kanamycin injection in concentrations of 0.25 percent (2.5 mg/mL) has been used as an irrigating solution in abscess cavities, pleural space, peritoneal and ventricular cavities.  Possible absorption of kanamycin by such routes must be taken into account and dosage adjustments should be arranged so that a maximum total dose of 1.5 g/day by all routes of administration is not exceeded.  Serum levels should be carefully monitored during treatment.

## Stability
Occasionally, some vials may darken during the shelf life of the product, but this does not indicate a loss of potency.
Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever container and solution permit.