Polymyxin B (Systemic, Topical)

Warning

• Administer IV, IM, or intrathecally only to hospitalized patients under constant supervision by a clinician.

• Nephrotoxic. Assess renal function prior to therapy. Reduce dosage in patients with renal damage and nitrogen retention. Polymyxin B-associated nephrotoxicity usually manifests as albuminuria, cellular casts, and azotemia. Discontinue in patients with decreasing urine output and increasing BUN.

• Neurotoxic. Neurotoxicity may be manifested by irritability, weakness, drowsiness, ataxia, perioral paresthesia, numbness of the extremities, and vision blurring. Usually associated with high polymyxin B serum concentrations found in patients with impaired renal function and/or nephrotoxicity.

• Neurotoxicity may result in respiratory paralysis from neuromuscular blockade, especially when given soon after anesthesia and/or muscle relaxants.

• Avoid concomitant or sequential use of neurotoxic and/or nephrotoxic drugs, particularly bacitracin, aminoglycosides (amikacin, gentamicin, kanamycin, neomycin, paromomycin, streptomycin, tobramycin), cephaloridine (not commercially available in the US), colistimethate/colistin, and viomycin (not commercially available in the US).

• Safety not established in pregnant women.