Drug reference

Polymyxin B

Polymyxin (cyclic cationic polypeptide) antibiotic · Antibiotic

Also known as Polymyxin B sulfate, Aerosporin

START

IV 15,000–25,000 units/kg/day in 2 divided doses (consider loading in critical illness)

TYPICAL MAX

~25,000 units/kg/day (normal renal function)

STOP IF

Progressive AKI or neuromuscular blockade/respiratory weakness

WATCH

Daily renal function, neurotoxic symptoms, concurrent nephro/neurotoxins

CDSCO approvedSchedule HATC J01XB02

Dose laddermg/d

Renal dose adjustmenteGFR mL/min/1.73m²

KDIGO 2024 + manufacturer label

Pharmacokineticsplasma · t hours

ONSET: 30min · IV onset
PEAK: 1h · end of infusion
t½: 6h · plasma t½
DURATION: 12h · q12h interval

EXCRETION

Primarily renal; slow tubular elimination

route + CYP

INTERACTIONS

12 major

SEVERE in our sources

PREGNANCY

Use only for life-threatening MDR infection when no alternative — limited data

FDA category + note

Top interactionssee all 12 →

AmikacinSevereDatabaseDDInter
AtracuriumSevereDatabaseDDInter
Botulinum Toxin Type ASevereDatabaseDDInter
Botulinum Toxin Type BSevereDatabaseDDInter

Available in India

33 branded formulations and 22 fixed-dose combinations. Look up specific brands in the Drugs workspace.

Mechanism

Cationic detergent-like binding to lipid A of Gram-negative LPS, disrupting outer and cytoplasmic membrane permeability → cell death; also endotoxin sequestration.

Indications

Serious infections by MDR Gram-negative bacilli (Pseudomonas, Acinetobacter, Klebsiella) when alternatives unsuitableTopical/ophthalmic/otic Gram-negative infections (combination products)

Dosing

Adult: IV: 15,000–25,000 units/kg/day in 2 divided doses (≈1.5–2.5 mg/kg/day; 10,000 units ≈ 1 mg). Loading dose used in critically ill per specialist guidance.
Pediatric: 15,000–40,000 units/kg/day divided (specialist).
Renal adjustment: Renally cleared — reduce dose/extend interval per CrCl; specialist/TDM where available.
Hepatic adjustment: No specific adjustment.
Geriatric: Reduced renal function — adjust dose, monitor closely.
Max dose: ~25,000 units/kg/day (normal renal function)

Pharmacokinetics

Onset

IV immediate

Peak effect

End of infusion

Duration

Dose-interval (q12h)

Half-life

~6 h (prolonged in renal impairment)

Bioavailability

Negligible oral; 100% IV

Protein binding

Moderate

Metabolism

Minimal

Excretion

Primarily renal (slow tubular handling)

Contraindications

Hypersensitivity to polymyxins
Caution (relative): significant renal impairment, concurrent nephro/neurotoxins, myasthenia gravis

Side effects

Common

Nephrotoxicity (dose-related, often reversible)Neurotoxicity: paraesthesia, dizziness, ataxiaInfusion-related reactionsInjection-site pain

Serious

Acute kidney injury
Neuromuscular blockade/respiratory paralysis (esp. with anaesthetics/relaxants)
Severe hypersensitivity

Pregnancy & lactation

Pregnancy

Use only for life-threatening MDR infection when no alternative — limited data

Lactation

Limited data; minimal oral absorption by infant — caution

Drug interactions

Amikacin

Severe

Database

Increased risk of acute kidney injury and respiratory depression/paralysis

Avoid concomitant use due to high risk of toxicity. If no other options, monitor renal function and respiratory status extremely closely. Be prepared for respiratory support.

Source: DDInter

Atracurium

Severe

Database

Clinical effect not specified

Source: DDInter

Botulinum Toxin Type A

Severe

Database

Clinical effect not specified

Source: DDInter

Botulinum Toxin Type B