Acute infections caused by susceptible strains of Pseudomonas aeruginosa:
Polymyxin B Sulfate is a drug of choice for the treatment of urinary tract infections, meningitis, and bloodstream infections caused by susceptible strains of Pseudomonas aeruginosa.

It may also be indicated in serious infections caused by susceptible strains of the following organisms when less toxic alternatives are ineffective or contraindicated:

• H. influenzae: particularly meningeal infections
• Escherichia coli: particularly urinary tract infections
• Aerobacter aerogenes: particularly bacteremia
• Klebsiella pneumoniae: particularly bacteremia

Polymyxin B Sulfate is the sulfate salt of polymyxins B1 and B2, produced by the growth of Bacillus polymyxa. It has a bactericidal effect against almost all Gram-negative bacilli. Polymyxins act by increasing the permeability of the bacterial cell membrane, leading to cell death.

Intravenous: Dissolve Polymyxin B 500,000 units in 300 to 500 ml solutions for parenteral Dextrose injection 5% for continuous drip.

Intramuscular: Dissolve Polymyxin B 500,000 units in 2 ml 0.9% Sodium Chloride solution. It is not recommended routinely because of severe pain at injection site, particularly in infants and children.

Intrathecal: Dissolve Polymyxin B 500,000 units in 10 ml 0.9% Sodium Chloride solution for 50,000 units per ml dosage unit.

In meningeal infections, Polymyxin B Sulfate should be administered only by the intrathecal route.

For IV route:

• Adult & Children (Normal kidney function): Dose (Units/kg/day) is 15,000-25,000 (Not exceed 25,000) and Dosage frequency/Duration is infusions may be given every 12 hours over a period of approximately 60 to 90 minutes.
• Adult & Children (Renal impairment): Dose (Units/kg/day) is Less than 15,000 and Dosage frequency/Duration is Infusions may be given every 12 hours over a period of approximately 60 to 90 minutes.
• Infants (Normal kidney function): Dose (Units/kg/day) is Maximum 40,000

For IM route:

• Adult & Children: Dose (Units/kg/day) is 25,000-30,000 and Dosage frequency/Duration is Dose should be reduced in the presence of renal impairment. The dosage may be divided and given at either 4 or 6 hour intervals.
• Infants (Normal kidney function): Dose (Units/kg/day) is Maximum 40,000

For Intrathecal:

• Children under 2 years of age: Dosage frequency/Duration is 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 the cerebrospinal fluid are negative and sugar content has returned to normal.
• Adults and children over 2 years of age: 50,000 units once daily 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.

Concurrent or sequential use of other neurotoxic and/or nephrotoxic drugs with Polymyxin B Sulfate should be avoided. These include bacitracin, kanamycin, streptomycin, tobramycin, amikacin, cephaloridine, cephalothin, paromycin, polymyxin E (colistin), neomycin, gentamicin, vancomycin, bumetanide, celecoxib, cisplatin, cyclosporine, diclofenac, misoprostol, diphenhydramine, ibuprofen, naproxen, esomeprazole, etodolac, general anesthetics, ketorolac, meloxicam, tenofovir, etc.

Clostridium difficile-associated diarrhea has been reported with the use of Polymyxin B. Nephrotoxic reactions include albuminuria, cylinduria, azotemia, and increased blood levels. Neurotoxic reactions include facial flushing, dizziness progressing to ataxia, drowsiness, peripheral paresthesias (circumoral and stocking-glove type), apnea due to concurrent use of curariform muscle relaxants or other neurotoxic drugs, or accidental overdose, and signs of meningeal irritation with intrathecal administration such as fever, headache, and stiff neck. Other reported reactions include drug fever, urticaria rash, severe pain at IM injection sites, and thrombophlebitis at IV injection sites.

There are no controlled studies in human pregnancy. Safety during pregnancy has not been established. There is no clear recommendation regarding use during lactation, and it is not known whether the drug is excreted in human milk.

Renal function should be assessed before starting therapy. During parenteral treatment, renal function and blood levels of the drug should be monitored frequently.

Polymyxin-induced toxicity due to overdose has been reported. Overdose may cause neuromuscular blockade leading to apnea, muscular weakness, vertigo, temporary facial paresthesia, slurred speech, vasomotor instability, visual disturbances, confusion, psychosis, and possible respiratory arrest.
It may also cause renal failure with decreased urine output and increased serum BUN and creatinine levels. There is no specific antidote for Polymyxin B Sulfate overdose. In case of overdose, the drug should be discontinued and symptomatic treatment should be started. Rapid diuresis with IV mannitol may help increase renal clearance and reduce serum drug levels. Hemodialysis or peritoneal dialysis may help manage renal complications.

Other antibacterial preparation

Before reconstitution, store below 30°C, protect from light, and keep out of the reach of children. After reconstitution or dilution, the unused portion should be stored at 2° to 8°C and discarded after 72 hours if not used.