Generic
Polymyxin B Sulfate
3 brands available in the market
At a glance
Polymyxin B Sulfate is used for acute infections caused by susceptible strains of Pseudomonas aeruginosa, particularly infections of the urinary tract, meninges, and bloodstream. It has bactericidal action against Gram-negative bacilli.
Description
Polymyxin B Sulfate is the sulfate salt of Polymyxins B1 & B2, produced by the growth of Bacillus polymyxa. Polymyxins increase bacterial cell membrane permeability, leading to cell death. It binds to phospholipids, alters permeability, and disrupts the bacterial cytoplasmic membrane of mostly gram-negative organisms, allowing leakage of intracellular constituents.
Indications
- Infections of urinary tract, meninges, and bloodstream caused by susceptible strains of Pseudomonas aeruginosa
- H. influenzae (meningeal infections)
- E. coli (urinary tract infections)
- Aerobacter aerogenes (bacteremia)
- Klebsiella pneumoniae (bacteremia)
Therapeutic class
Other antibacterial preparation
Pharmacological class
Polymyxin Antibiotic
Pharmacology
Polymyxin B Sulfate binds to phospholipids in the bacterial cytoplasmic membrane, altering permeability and disrupting the membrane, causing leakage of intracellular constituents and cell death. It has bactericidal action against almost all Gram-negative bacilli.
Mechanism of action
Kills bacteria by disrupting the bacterial cytoplasmic membrane.
Dosage
Adult Dose (Parenteral):
- IV (Susceptible infections): 15,000-25,000 U/kg/day (continuous IV drip or intermittent infusion q12hr, 60-90 min); max 2,000,000 U/day
- IM (Susceptible infections): 25,000-30,000 U/kg/day in divided doses q4-6hr; max 2,000,000 U/day
- Intrathecal (Meningitis): 50,000 U once daily for 3-4 days, then on alternate days for at least 2 weeks after CSF cultures negative and glucose normal
Pediatric Dose (<2 years):
- IV/IM: Max 40,000 U/kg/day
- Intrathecal: 20,000 U once daily for 3-4 days or 25,000 U every other day
Administration
- IV: Dilute 500,000 U in 300-500 mL D5W; infuse over 60-90 min
- IM: Reconstitute vial with 2 mL SWI, NS, or procaine HCl 1% solution; give deep into upper outer quadrant of gluteal muscles
- Intrathecal: Reconstitute vial with 10 mL NS; DO NOT use procaine HCl for IT
Missed dose
If you miss a dose, consult your doctor.
Side effects
Side Effects:
- Nephrotoxicity (albuminuria, cylinduria, azotemia)
- Neurotoxicity (facial flushing, dizziness, ataxia, drowsiness, peripheral paresthesias)
- Apnea (with curariform muscle relaxants, other neurotoxic drugs, or overdosage)
- Signs of meningeal irritation (fever, headache, stiff neck) with intrathecal administration
- Drug fever, urticarial rash
- Severe pain at IM injection sites, thrombophlebitis at IV sites
- Clostridium difficile-associated diarrhea
Precautions & warnings
- Baseline renal function testing; frequent monitoring of renal function and blood levels during parenteral therapy
- Caution in oliguria, myasthenia gravis, pregnancy, renal disease
- Inactivated by strong acidic or alkaline solutions
- Discontinue if diminished urine output, rise in SCr or BUN, or signs of respiratory paralysis
- Do not use IM routinely (especially in children) due to severe injection site pain
Contraindications
- Hypersensitivity to polymyxins
- Concurrent use with nephrotoxic and/or neurotoxic drugs and neuromuscular blockers
Drug interactions
- Potentially fatal: Additive neurotoxic or nephrotoxic effect with bacitracin, streptomycin, neomycin, kanamycin, gentamicin, tobramycin, amikacin, cephaloridine, paromomycin, viomycin, colistin
- Increased risk of respiratory paralysis with neuromuscular blockers (e.g., anaesthetics, muscle relaxants)
Food interactions
Not food-related (parenteral use).
Use in pregnancy
Use in Pregnancy: Pregnancy Category B; use when benefits outweigh risks; no controlled human data.
Pregnancy Category: B — always consult a doctor before taking during pregnancy.
Use in lactation
Use in Lactation: Unknown if excreted in human milk; caution required.
Pediatric use
Pediatric dose based on age and weight; <2 years: IV/IM max 40,000 U/kg/day; Intrathecal: 20,000-25,000 U.
Geriatric use
Elderly patients require renal function monitoring; dose adjustment may be needed.
Renal / hepatic impairment
Renal Impairment: CrCl >20 mL/min: 75-100% usual dose/day divided q12hr; CrCl 5-20 mL/min: 50% usual dose/day divided q12hr; CrCl <5 mL/min: 15% usual dose/day q12hr
Hepatic Impairment: Caution in liver disease; consult your doctor.
Overdose effects
Overdose may cause neuromuscular blockade (apnea, muscular weakness, vertigo), renal failure; no specific antidote; discontinue drug, symptomatic treatment, rapid diuresis with mannitol, hemodialysis/peritoneal dialysis.
Storage conditions
Before reconstitution, do not store above 30°C; keep away from light; after reconstitution, store at 2-8°C and discard after 72 hours.
Chemical structure
Polymyxin B Sulfate