Polymyxin B: The Antibiotic for Severe Bacterial Infections
What is Polymyxin B?
Polymyxin B is an antibiotic used to treat severe gram-negative bacterial infections, particularly those resistant to other antibiotics. It is commonly used in hospital settings for pneumonia, sepsis, and wound infections caused by multidrug-resistant bacteria.
How Polymyxin B Works
Polymyxin B binds to the lipopolysaccharides in the outer membrane of gram-negative bacteria, disrupting their structure and increasing their permeability. This leads to the destruction of the bacterial cell and ultimately kills the bacteria.
When to Use Polymyxin B
● Severe Infections: It is used to treat serious infections caused by drug-resistant bacteria, including pneumonia, sepsis, and urinary tract infections.
● Topical Use: Polymyxin B is sometimes used topically to treat skin infections caused by susceptible bacteria.
Dosage
● Adult Dose (Intravenous): Typically, 2.5 mg/kg every 12 hours.
● Topical Use: Polymyxin B is applied topically as an ointment or cream for infected wounds.
Side Effects
● Common Effects: Nephrotoxicity (kidney damage), neurotoxicity (numbness, tingling), and allergic reactions.
● Serious Adverse Effects: Kidney failure, respiratory distress, and neurological toxicity.
Common Brands: Polymycin D