polymyxin B and colistin (polymyxin E) are used in the treatment bacterial diseases.
MOA: Polymyxins bind to the outer membrane of gram-negative bacteria (P. aeruginosa and coliform organisms in particular)., leading to disruption of membrane stability and leakage of cellular contents.
Therapeutic uses:
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In combination with neomycin, polymyxin B is used as a bladder irrigant to reduce the risk of catheter- associated infections.
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Polymyxin B also is applied Topically in combination with other antibiotics for infections of skin, eye or ear. w/ **Neomycin & Gentamicin
Adverse effects:
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Nephro-toxicity.
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Neuro-toxicity. recognized by perioral paresthesia, numbness, weakness, ataxia and blurred vision.
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These drugs precipitate respiratory arrest (due to Neuromuscular blocking effect) especially both in patients given muscle relaxants during anesthesia and in persons suffering from myasthenia gravis.