Poly-MxB Dosage/Direction for Use

Intravenous: Dissolve 500,000 Units Polymyxin B Sulfate in 300 to 500 ml of 5% dextrose in water for continuous intravenous drip.
Adults and Children: 15,000 to 25,000 units/kg body weight/day in individuals with normal kidney function. This amount should be reduced from 15,000 units/kg downward for individuals with kidney impairment. Infusions may be given every 12 hours; however, the total daily dose must not exceed 25,000 units/kg/day.
Infants: Infants with normal kidney function may receive up to 40,000 units/kg/day without adverse effects.
Intramuscular: Not recommended routinely because of severe pain at injection sites, particularly in infants and children. Dissolve 500,000 Units Polymyxin B Sulfate in 2 ml sterile distilled water (Sterile Water for Injection) or sterile physiologic saline (Sodium Chloride Injection) or 1% procaine hydrochloride solution.
Adults and Children: 25,000 to 30,000 units/kg/day. This should be reduced in the presence of renal impairment. The dosage may be divided and given at either 4 or 6 hour intervals.
Infant: Infants with normal kidney function may receive up to 40,000 units/kg/day without adverse effects.
Note: Doses as high as 45,000 units/kg/day have been used in limited clinical studies in treating prematures and newborn infants for sepsis caused by Ps. aeruginosa.
Intrathecal: A treatment of choice for Ps. aeruginosa meningitis.
Dissolve 500,000 Units Polymyxin B Sulphate in 5 ml of sterile physiological saline (0.9% Sodium Chloride Injection) for 100,000 Units per ml. Dilute further using 5 ml of same solvent to obtain 50,000 Units per ml dosage units.
Adults and Children Over 2 Years of Age: Dosage is 50,000 Units once daily intrathecally for 3 to 4 days, then 50,000 Units once every other day for at least 2 weeks after cultures of the cerebrospinal fluid are negative and sugar content has returned to normal.
Children Under 2 Years of Age: 20,000 Units once daily, intrathecally for 3 to 4 days or 25,000 Units once every other day. Continue with a dose of 25,000 Units once every other day for at least 2 weeks after cultures of cerebrospinal fluid are negative and sugar content has returned to normal.
IN THE INTEREST OF SAFETY, SOLUTIONS FOR PARENTERAL USE SHOULD BE STORED UNDER REFRIGERATION AND ANY UNUSED PORTION SHOULD BE DISCARDED AFTER 72 HOURS.