Drug interactions
Polymyxin b + Rocuronium
Severity: Major
Polymyxin b and Rocuronium: major interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Polymyxin B has neuromuscular blocking properties and can intensify and prolong rocuronium paralysis. This can lead to prolonged respiratory muscle weakness or apnea, particularly with renal dysfunction.
What this interaction means in plain words
Polymyxin b and Rocuronium can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Polymyxin b belongs to Anti Bacterial; Rocuronium belongs to Musculoskeletal.
Why it happens
Additive neuromuscular blockade through presynaptic inhibition of acetylcholine release and reduced postsynaptic sensitivity from polymyxin B.
What to do
Avoid concurrent use where an alternative antibiotic is suitable; if needed, reduce rocuronium dose and monitor with train-of-four. Have ventilatory support ready; neostigmine reversal may be incomplete.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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Other interactions of Rocuronium
Other interactions of Polymyxin b
- Cidofovir + Polymyxin b Contraindicated
- Colistin + Polymyxin b Contraindicated
- Acyclovir + Polymyxin b Major
- Adefovir + Polymyxin b Major
- Amikacin + Polymyxin b Major
- Amphotericin b + Polymyxin b Major
Frequently asked questions
Can I take Polymyxin b with Rocuronium?
MediHelp rates the interaction as major. Polymyxin b and Rocuronium can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Polymyxin B has neuromuscular blocking properties and can intensify and prolong rocuronium paralysis. This can lead to prolonged respiratory muscle weakness or apnea, particularly with renal dysfunction.
How serious is the interaction between Polymyxin b and Rocuronium?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid concurrent use where an alternative antibiotic is suitable; if needed, reduce rocuronium dose and monitor with train-of-four. Have ventilatory support ready; neostigmine reversal may be incomplete.
What other medicines interact with Rocuronium?
MediHelp also lists interactions of Rocuronium with, for example, Amikacin, Bacitracin-neomycin-polymyxin, Capreomycin. The full list is on the Rocuronium page.
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