Polymyxin B
Polymyxin B is a polypeptide antibiotic derived from Bacillus polymyxa. It acts by binding to phospholipids in the bacterial cytoplasmic membrane of Gram-negative bacteria, disrupting membrane integrity and causing cell death. Because of its potential for nephrotoxicity and neurotoxicity, systemic use is typically reserved for severe, multi-drug resistant infections under close clinical supervision.
Dosage by Body Weight
Administered intravenously, intramuscularly, intrathecally, or topically depending on the site of infection. Systemic dosing is strictly calculated based on body weight and renal function. Standard systemic pediatric dosage is 15,000 to 25,000 USP units/kg of body weight per day, divided and administered every 12 hours.
- Body Weight
- Below 5 kg
- Dose
- 15,000 to 25,000 USP units/kg/day
- Frequency
- Divided into 2 doses (every 12 hours)
- Tracking Notes
- Not routinely used in neonates unless absolutely necessary. Requires intensive monitoring of renal function and fluid balance.
- Body Weight
- 5-7 kg
- Dose
- 75,000 to 175,000 USP units daily
- Frequency
- Divided into 2 doses (every 12 hours) intravenously
- Tracking Notes
- Infuse slowly over 60 to 90 minutes. Ensure adequate hydration to mitigate nephrotoxicity risk.
- Body Weight
- 8-10 kg
- Dose
- 120,000 to 250,000 USP units daily
- Frequency
- Divided into 2 doses (every 12 hours) intravenously
- Tracking Notes
- Monitor serum creatinine and output daily. Dose adjustments are critical in case of renal impairment.
- Body Weight
- 11-15 kg
- Dose
- 165,000 to 375,000 USP units daily
- Frequency
- Divided into 2 doses (every 12 hours) intravenously
- Tracking Notes
- Ensure serum drug levels are monitored if possible. Watch for neurotoxic symptoms such as paresthesia or dizziness.
- Body Weight
- 16-20 kg
- Dose
- 240,000 to 500,000 USP units daily
- Frequency
- Divided into 2 doses (every 12 hours) intravenously
- Tracking Notes
- Avoid co-administration with other nephrotoxic or neurotoxic drugs (such as aminoglycosides or neuromuscular blockers).
| Body Weight | Dose | Frequency | Tracking Notes |
|---|---|---|---|
| Below 5 kg | 15,000 to 25,000 USP units/kg/day | Divided into 2 doses (every 12 hours) | Not routinely used in neonates unless absolutely necessary. Requires intensive monitoring of renal function and fluid balance. |
| 5-7 kg | 75,000 to 175,000 USP units daily | Divided into 2 doses (every 12 hours) intravenously | Infuse slowly over 60 to 90 minutes. Ensure adequate hydration to mitigate nephrotoxicity risk. |
| 8-10 kg | 120,000 to 250,000 USP units daily | Divided into 2 doses (every 12 hours) intravenously | Monitor serum creatinine and output daily. Dose adjustments are critical in case of renal impairment. |
| 11-15 kg | 165,000 to 375,000 USP units daily | Divided into 2 doses (every 12 hours) intravenously | Ensure serum drug levels are monitored if possible. Watch for neurotoxic symptoms such as paresthesia or dizziness. |
| 16-20 kg | 240,000 to 500,000 USP units daily | Divided into 2 doses (every 12 hours) intravenously | Avoid co-administration with other nephrotoxic or neurotoxic drugs (such as aminoglycosides or neuromuscular blockers). |
Formulation
Purpose
Treatment of acute and serious infections of the urinary tract, meninges, and bloodstream caused by susceptible strains of Pseudomonas aeruginosa and other Gram-negative bacilli, typically when other less toxic antibiotics are ineffective or contraindicated.
Generic Name
Polymyxin B SulfateBranded Drug Names
Polymyxin B is listed as a generic drug name. Common branded medicines that may contain the same active ingredient include:
Scheduled Drug
Yes. This medicine should be supplied or used only according to applicable prescription and regulatory requirements.