Polymyxin B

Generic Name: polymyxin b

Over-the-Counter (OTC)

Brand Names:

Polymyxin B

DESCRIPTION Polymyxin B for Injection, USP is one of a group of basic polypeptide antibiotics derived from B polymyxa (B aerosporous) . Polymyxin B sulfate is the sulfate salt of Polymyxins B 1 and B 2 , which are produced by the growth of Bacillus polymyxa (Prazmowski) Migula (Fam. Bacillacea). Polymyxin B sulfate, USP is a white or off-white powder. It has a potency of not less than 6,000 polymyxin B units per mg, calculated on the anhydrous basis.

Overview

DESCRIPTION Polymyxin B for Injection, USP is one of a group of basic polypeptide antibiotics derived from B polymyxa (B aerosporous) . Polymyxin B sulfate is the sulfate salt of Polymyxins B 1 and B 2 , which are produced by the growth of Bacillus polymyxa (Prazmowski) Migula (Fam. Bacillacea). Polymyxin B sulfate, USP is a white or off-white powder. It has a potency of not less than 6,000 polymyxin B units per mg, calculated on the anhydrous basis.

Uses

INDICATIONS AND USAGE Acute Infections Caused by Susceptible Strains of Pseudomonas aeruginosa. Polymyxin B sulfate is a drug of choice in the treatment of infections of the urinary tract, meninges, and bloodstream caused by susceptible strains of Ps. aeruginosa . It may also be used topically and subconjunctivally in the treatment of infections of the eye caused by susceptible strains of Ps. aeruginosa . It may be indicated in serious infections caused by susceptible strains of the following organisms, when less potentially toxic drugs are ineffective or contraindicated: H influenzae , specifically meningeal infections. Escherichia coli , specifically urinary tract infections. Aerobacter aerogenes , specifically bacteremia. Klebsiella pneumoniae , specifically bacteremia.

Dosage

DOSAGE AND ADMINISTRATION PARENTERAL: Intravenous Dissolve 500,000 polymyxin B units in 300 to 500 mL solutions for parenteral dextrose injection 5% for continuous drip. Adults and children 15,000 to 25,000 units/kg body weight/day in individuals with normal kidney function. This amount should be reduced from 15,000 units/kg downward for individuals with kidney impairment. Infusions may be given every 12 hours; however, the total daily dose must not exceed 25,000 units/kg/day. Infants Infants with normal kidney function may receive up to 40,000 units/kg/day without adverse effects. Intramuscular Not recommended routinely because of severe pain at injection sites, particularly in infants and children.

Side Effects

ADVERSE REACTIONS See WARNING box. Nephrotoxic reactions: Albuminuria, cylinduria, azotemia, and rising blood levels without any increase in dosage. Renal system reactions: electrolyte and acid/base abnormalities (i.e., Pseudo-Bartter syndrome) Neurotoxic reactions: Facial flushing, dizziness progressing to ataxia, drowsiness, peripheral paresthesias (circumoral and stocking glove), apnea due to concurrent use of curariform muscle relaxants, other neurotoxic drugs or inadvertent overdosage, and signs of meningeal irritation with intrathecal administration, e.g., fever, headache, stiff neck and increased cell count and protein cerebrospinal fluid.

Warnings

WARNING CAUTION: WHEN THIS DRUG IS GIVEN INTRAMUSCULARLY, INTRAVENOUSLY AND/OR INTRATHECALLY, IT SHOULD BE GIVEN ONLY TO HOSPITALIZED PATIENTS, SO AS TO PROVIDE CONSTANT SUPERVISION BY A PHYSICIAN. RENAL FUNCTION SHOULD BE CAREFULLY DETERMINED AND PATIENTS WITH RENAL DAMAGE AND NITROGEN RETENTION SHOULD HAVE REDUCED DOSAGE. PATIENTS WITH NEPHROTOXICITY DUE TO POLYMYXIN B SULFATE USUALLY SHOW ALBUMINURIA, CELLULAR CASTS, AND AZOTEMIA. WARNINGS Clostridium difficile associated diarrhea (CDAD) has been reported with use of nearly all antibacterial agents, including Polymyxin B for Injection, and may range in severity from mild diarrhea to fatal colitis. Treatment with antibacterial agents alters the normal flora of the colon leading to overgrowth of C. difficile . C. difficile produces toxins A and B which contribute to the development of CDAD. Hypertoxin producing strains of C. difficile cause increased morbidity and mortality, as these infections can be refractory to antimicrobial therapy and may require colectomy. CDAD must be considered in all patients who present with diarrhea following antibiotic use. CONTRAINDICATIONS This drug is contraindicated in persons with a prior history of hypersensitivity reactions to polymyxins.

Storage

HOW SUPPLIED Polymyxin B for Injection, USP is a sterile, white lyophilized cake or powder and is supplied as follows: 500,000 Units per Vial 10 Vials in a Carton NDC 55150-234-10 Storage recommendations: Before reconstitution: Store at 20° to 25°C (68° to 77°F) [see USP Controlled Room Temperature]. Protect from light. Retain in carton until time of use.

Frequently Asked Questions

What is Polymyxin B used for?

INDICATIONS AND USAGE Acute Infections Caused by Susceptible Strains of Pseudomonas aeruginosa. Polymyxin B sulfate is a drug of choice in the treatment of infections of the urinary tract, meninges, and bloodstream caused by susceptible strains of Ps. aeruginosa . It may also be used topically and subconjunctivally in the treatment of infections of the eye caused by susceptible strains of Ps. aeruginosa . It may be indicated in serious infections caused by susceptible strains of the following organisms, when less potentially toxic drugs are ineffective or contraindicated: H influenzae , specifically meningeal infections. Escherichia coli , specifically urinary tract infections. Aerobacter aerogenes , specifically bacteremia. Klebsiella pneumoniae , specifically bacteremia.

What are the side effects of Polymyxin B?

ADVERSE REACTIONS See WARNING box. Nephrotoxic reactions: Albuminuria, cylinduria, azotemia, and rising blood levels without any increase in dosage. Renal system reactions: electrolyte and acid/base abnormalities (i.e., Pseudo-Bartter syndrome) Neurotoxic reactions: Facial flushing, dizziness progressing to ataxia, drowsiness, peripheral paresthesias (circumoral and stocking glove), apnea due to concurrent use of curariform muscle relaxants, other neurotoxic drugs or inadvertent overdosage, and signs of meningeal irritation with intrathecal administration, e.g., fever, headache, stiff neck and increased cell count and protein cerebrospinal fluid.

What are the important warnings for Polymyxin B?

WARNING CAUTION: WHEN THIS DRUG IS GIVEN INTRAMUSCULARLY, INTRAVENOUSLY AND/OR INTRATHECALLY, IT SHOULD BE GIVEN ONLY TO HOSPITALIZED PATIENTS, SO AS TO PROVIDE CONSTANT SUPERVISION BY A PHYSICIAN. RENAL FUNCTION SHOULD BE CAREFULLY DETERMINED AND PATIENTS WITH RENAL DAMAGE AND NITROGEN RETENTION SHOULD HAVE REDUCED DOSAGE. PATIENTS WITH NEPHROTOXICITY DUE TO POLYMYXIN B SULFATE USUALLY SHOW ALBUMINURIA, CELLULAR CASTS, AND AZOTEMIA. WARNINGS Clostridium difficile associated diarrhea (CDAD) has been reported with use of nearly all antibacterial agents, including Polymyxin B for Injection, and may range in severity from mild diarrhea to fatal colitis. Treatment with antibacterial agents alters the normal flora of the colon leading to overgrowth of C. difficile . C. difficile produces toxins A and B which contribute to the development of CDAD. Hypertoxin producing strains of C. difficile cause increased morbidity and mortality, as these infections can be refractory to antimicrobial therapy and may require colectomy. CDAD must be considered in all patients who present with diarrhea following antibiotic use. CONTRAINDICATIONS This drug is contraindicated in persons with a prior history of hypersensitivity reactions to polymyxins.

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Medical Disclaimer

This drug information is for educational purposes only and should not replace professional medical advice. Drug information is sourced from the FDA National Drug Code Directory and Structured Product Labeling. Always consult with a healthcare provider before starting, stopping, or changing any medication.