Polymyxin b sulfate

Polymyxin B sulfate is an antibiotic primarily used for the treatment of Gram-negative bacterial infections. It belongs to the polymyxin group of antibiotics, which are cyclic polypeptides with a long hydrophobic tail. Polymyxin B sulfate is derived from the bacterium Bacillus polymyxa.

Mechanism of Action

Polymyxin B sulfate works by interacting with the lipopolysaccharides in the outer membrane of Gram-negative bacteria. This interaction disrupts the bacterial cell membrane, leading to increased permeability and ultimately cell death. The antibiotic is particularly effective against Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, and Acinetobacter baumannii.

Clinical Uses

Polymyxin B sulfate is used in various forms, including topical, ophthalmic, and intravenous formulations. It is often reserved for severe infections where other antibiotics are ineffective due to its potential for nephrotoxicity and neurotoxicity. Common clinical applications include:

• Treatment of urinary tract infections
• Management of meningitis
• Treatment of bacteremia
• Use in burn patients to prevent infections

Side Effects

The use of Polymyxin B sulfate can lead to several side effects, primarily due to its toxicity. These include:

• Nephrotoxicity: Damage to the kidneys, which can lead to acute kidney injury.
• Neurotoxicity: Symptoms may include dizziness, weakness, and numbness.
• Allergic reactions: Rash, fever, and anaphylaxis in severe cases.

Resistance

Bacterial resistance to Polymyxin B sulfate is relatively rare but has been increasing. Resistance mechanisms include modifications to the bacterial outer membrane that reduce the binding affinity of the antibiotic.

Related Antibiotics

Polymyxin B sulfate is closely related to colistin (Polymyxin E), another member of the polymyxin group. Both antibiotics share similar mechanisms of action and clinical uses but differ in their pharmacokinetic properties.

See Also

• Antibiotic resistance
• Gram-negative bacteria
• Nephrotoxicity
• Neurotoxicity
• Pseudomonas aeruginosa
• Escherichia coli
• Klebsiella pneumoniae
• Acinetobacter baumannii