<unk> , also known as polymyxin E, is an antibiotic medication used as a last-resort treatment for multidrug-resistant Gram-negative infections including pneumonia. These may involve bacteria such as Pseudomonas aeruginosa, Klebsiella pneumoniae, or Acinetobacter. It comes in two forms:<unk> ethate sodium can be injected into a vein, injected into a muscle, or inhaled, and<unk>  sulfate is mainly applied to the skin or taken by mouth.<unk> ethate sodium is a prodrug; it is produced by the reaction of<unk>  with formaldehyde and sodium bisulfite, which leads to the addition of a sulfomethyl group to the primary amines of<unk> .<unk> ethate sodium is less toxic than<unk>  when administered parenterally. In aqueous solutions it undergoes hydrolysis to form a complex mixture of partially sulfomethylated derivatives, as well as<unk> . Resistance to<unk>  began to appear as of 2015. Common side effects of the injectable form include kidney problems and neurological problems. Other serious side effects may include anaphylaxis, muscle weakness, and Clostridium difficile-associated diarrhea. The inhaled form may result in constriction of the bronchioles. It is unclear if use during pregnancy is safe for the fetus.<unk>  is in the polymyxin class of medications. It works by breaking down the cytoplasmic membrane, which generally results in bacterial cell death.<unk>  was discovered in 1947 and<unk> ethate sodium was approved for medical use in the United States in 1970. It is on the World Health Organization's List of Essential Medicines. The World Health Organization classifies<unk>  as critically important for human medicine. It is available as a generic medication. It is derived from bacteria of the genus Paenibacillus.
Colistin
Resistin
Meropenem
Vancomycin
Ertapenem
Fosfomycin
Teicoplanin
Ciprofloxacin