Colistimethate sodium

Colistimethate sodium is an antibiotic used in the treatment of certain bacterial infections. It is a member of the polymyxin class of antibiotics and is derived from the bacterium Paenibacillus polymyxa. Colistimethate sodium is particularly effective against Gram-negative bacteria, including Pseudomonas aeruginosa and Acinetobacter baumannii.

History

Colistimethate sodium was first isolated in 1947 and has been in clinical use since the 1950s. It fell out of favor due to concerns about nephrotoxicity and neurotoxicity, but has seen a resurgence in use due to the rise of multidrug-resistant bacterial infections.

Mechanism of action

Colistimethate sodium works by binding to the lipopolysaccharide on the outer membrane of Gram-negative bacteria, disrupting the cell membrane and leading to cell death. It is a bactericidal antibiotic, meaning it kills bacteria rather than merely inhibiting their growth.

Clinical use

Colistimethate sodium is used to treat serious infections caused by multidrug-resistant Gram-negative bacteria, particularly P. aeruginosa and A. baumannii. It is often used as a last-resort treatment when other antibiotics are ineffective. It can be administered intravenously, inhaled, or applied topically.

Side effects

The most common side effects of colistimethate sodium are kidney damage and neurological problems, including dizziness, weakness, and numbness. These side effects are more likely to occur with higher doses and longer treatment durations.

Resistance

Resistance to colistimethate sodium can occur through several mechanisms, including changes in the bacterial outer membrane that prevent the antibiotic from binding, and the production of enzymes that inactivate the antibiotic.

See also

• Polymyxin B
• Antibiotic resistance
• Multidrug resistance