Polymyxin B sulfate, parenteral
Polymyxin B sulfate, parenteral (Aerosporin)
Polymyxin B Sulfate
(pol-ee- MIX-in)
Pregnancy Category: C Aerosporin (Rx)
Polymyxin B sulfate, sterile ophthalmic
Polymyxin B sulfate, sterile ophthalmic
Polymyxin B Sulfate
(pol-ee- MIX-in)
Pregnancy Category: C (Rx)

Classification: Antibiotic, polymyxin

See Also: See also Anti-Infectives .

Action/Kinetics: Derived from the spore-forming soil bacterium Bacillus polymyxa. Bactericidal against most gram-negative organisms; rapidly inactivated by alkali, strong acid, and certain metal ions. Increases the permeability of the plasma cell membrane of the bacterium (i.e., similar to detergents), causing leakage of essential metabolites and ultimately inactivation. Peak serum levels: IM, 2 hr. t 1/2: 4.3-6 hr. Longer in presence of renal impairment. Sixty percent of drug excreted in urine. Virtually unabsorbed from the GI tract except in newborn infants. Remains in plasma after parenteral administration.

Uses: Systemic: Acute infections of the urinary tract and meninges, septicemia caused by Pseudomonas aeruginosa. Meningeal infections caused by Haemophilus influenzae UTIs caused by Escherichia coli bacteremia caused by Enterobacter aerogenes or Klebsiella pneumoniae. Combined with neomycin for irrigation of the urinary bladder to prevent bacteriuria and bacteremia from indwelling catheters.
Ophthalmic: Conjunctival and corneal infections (e.g., conjunctivitis, keratitis, keratoconjunctivitis, corneal ulcers, blepharitis, blepharoconjunctivitis, acute meibomianitis, dacryocystitis) due to E. coli, H. influenzae, H. parainfluenzae, K. pneumoniae, E. aerogenes and P. aeruginosa. Used alone or in combination for ear infections.

Contraindications: Hypersensitivity. A potentially toxic drug to be reserved for the treatment of severe, resistant infections in hospitalized clients. Not indicated for clients with severely impaired renal function or nitrogen retention. Ophthalmic use in dendritic keratitis, vaccinia, varicella, mycobacterial infections of the eye, fungal diseases of the eye, use with steroid combinations after uncomplicated removal of a foreign body from the cornea. Ophthalmic use in deep-seated ophthalmic infections or in those likely to become systemic infections.

Special Concerns: Safe use during pregnancy has not been established.

Side Effects: Nephrotoxic: Albuminuria, cylindruria, azotemia, hematuria, proteinuria, leukocyturia, electrolyte loss. Neurologic: Dizziness, flushing of face, mental confusion, irritability, nystagmus, muscle weakness, drowsiness, paresthesias, blurred vision, slurred speech, ataxia, coma, seizures. Neuromuscular blockade may lead to respiratory paralysis. GI: N&V, diarrhea, abdominal cramps. Miscellaneous: Fever, urticaria, skin exanthemata, eosinophilia, anaphylaxis.
Following intrathecal use: Meningeal irritation with fever, stiff neck, headache, increase in leukocytes and protein in the CSF. Nerve-root irritation may result in neuritic pain and urine retention. Following IM use: Irritation, severe pain. Following IV use: Thrombophlebitis. Following ophthalmic use: Burning, stinging, irritation, inflammation, angioneurotic edema, itching, urticaria, vesicular and maculopapular dermatitis.

Laboratory Test Alterations: False + or levels of urea nitrogen and creatinine. Casts and RBCs in urine.

Drug Interactions: Aminoglycoside antibiotics / Additive nephrotoxic effects Cephalosporins / Risk of renal toxicity Phenothiazines / Risk of respiratory depression Skeletal muscle relaxants (surgical) / Additive muscle relaxation

How Supplied: Powder for injection: 500,000 U

Dosage
•IV Infections.
Adults and children: 15,00025,000 units/kg/day (maximum) in divided doses q 12 hr. Infants, up to 40,000 units/kg/day.
•IM
Not usually recommended due to pain at injection site.
Infections.
Adults and children: 25,000-30,000 units/kg/day in divided doses q 4-6 hr. Infants, up to 40,000 units/kg/day.
Both IV and IM doses should be reduced in renal impairment.

•Intrathecal Meningitis.
Adults and children over 2 years: 50,000 units/day for 3-4 days; then, 50,000 units every other day until 2 weeks after cultures are negative; children under 2 years, 20,000 units/day for 3-4 days or 25,000 units once every other day; dosage of 25,000 units should be continued every other day for 2 weeks after cultures are negative.
•Ophthalmic Solution
1-2 gtt 2-6 times/day, depending on the infection. Treatment may be necessary for 1-2 months or longer.