FOR TOPICAL APPLICATION POLYMYXIN B IS USUALLY AVAILABLE AS A 0.1% SOLUTION OR OINTMENT COMBINED WITH OTHER DRUGS. PARENTERAL DOSES HAVE RANGED FROM 15 000 TO 25 000 UNITS/KG (ABOUT 1.5 TO 2.5 MG/KG) DAILY, PREFERABLY BY INTRAVENOUS INFUSION, ALTHOUGH THE INTRAMUSCULAR ROUTE HAS BEEN USED DESPITE THE SEVERE PAIN WHICH MAY BE ASSOCIATED WITH IT. HIGHER DOSES HAVE BEEN GIVEN TO NEONATES, BUT DOSAGE MUST BE REDUCED IN PATIENTS WITH RENAL IMPAIRMENT.
POLYMYXIN B HAS ALSO BEEN GIVEN INTRATHECALLY IN MENINGEAL INFECTION, AND BY SUBCONJUNCTIVAL INJECTION FOR EYE INFECTIONS.