Polymyxin b

Acute Infections Caused by Susceptible Strains of Pseudomonas aeruginosa. Polymyxin B sulfate is a drug of choice in the treatment of infections of the urinary tract, meninges, and blood-stream caused by susceptible strains of Ps. aeruginosa. It may also be used topically and subconjunctivally in the treatment of infections of the eye caused by susceptible strains of Ps. aeruginosa. It may be indicated in serious infections caused by susceptible strains of the following organisms, when less potentially toxic drugs are ineffective or contraindicated: H influenzae, specifically meningeal infections. Escherichia coli, specifically urinary tract infections. Aerobacter aerogenes, specifically bacteremia. Klebsiella pneumoniae, specifically bacteremia. NOTE: IN MENINGEAL INFECTIONS, POLYMYXIN B SULFATE SHOULD BE ADMINISTERED ONLY BY THE INTRATHECAL ROUTE.

PARENTERAL Intravenous Dissolve 500,000 polymyxin B units in 300 to 500 mL solutions for parenteral 5% Dextrose Injection for continuous 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 Polymyxin B units in 2 mL Sterile Water for Injection or 0.9 % Sodium Chloride Injection or Procaine Hydrochloride Injection 1%. Adults and children 25,000 to 30,000 units/kg/day.

This drug is contraindicated in persons with a prior history of hypersensitivity reactions to polymyxins.

WARNING CAUTION: WHEN THIS DRUG IS GIVEN INTRAMUSCULARLY AND/OR INTRATHECALLY, IT SHOULD BE GIVEN ONLY TO HOSPITALIZED PATIENTS, SO AS TO PROVIDE CONSTANT SUPERVISION BY A PHYSICIAN. RENAL FUNCTION SHOULD BE CAREFULLY DETERMINED AND PATIENTS WITH RENAL DAMAGE AND NITROGEN RETENTION SHOULD HAVE REDUCED DOSAGE. PATIENTS WITH NEPHROTOXICITY DUE TO POLYMYXIN B SULFATE USUALLY SHOW ALBUMINURIA, CELLULAR CASTS, AND AZOTEMIA. Clostridium difficile associated diarrhea (CDAD) has been reported with use of nearly all antibacterial agents, including Polymyxin B for Injection, and may range in severity from mild diarrhea to fatal colitis. Treatment with antibacterial agents alters the normal flora of the colon leading to overgrowth of C. difficile. C. difficile produces toxins A and B which contribute to the development of CDAD.

See WARNING box. Nephrotoxic reactions Albuminuria, cylinduria, azotemia, and rising blood levels without any increase in dosage. Renal system reactions electrolyte and acid/base abnormalities (i.e.,Pseudo-Bartter syndrome) Neurotoxic reactions Facial flushing, dizziness progressing to ataxia, drowsiness, peripheral paresthesias (circumoral and stocking glove), apnea due to concurrent use of curariform muscle relaxants, other neurotoxic drugs or inadvertent overdosage, and signs of meningeal irritation with intrathecal administration, e.g., fever, headache, stiff neck and increased cell count and protein cerebrospinal fluid. Other reactions occasionally reported Drug fever, urticarial rash, pain (severe) at intramuscular injection sites, and thrombophlebitis at intravenous injection sites.

Store at 20° to 25°C (68° to 77°F) Protect from light. After reconstitution Product must be stored under refrigeration, between 2° to 8°C (36° to 46°F) and any unused portion should be discarded after 72 hours.