Drug interactions
Polymyxin b + Tacrolimus
Severity: Major
Polymyxin b and Tacrolimus: 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
Both drugs are nephrotoxic, and combined use raises the risk of acute kidney injury. Polymyxin B also carries neurotoxic and ototoxic potential, and accumulation from reduced renal function can worsen these effects.
What this interaction means in plain words
Polymyxin b and Tacrolimus 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; Tacrolimus belongs to Miscellaneous.
Why it happens
Additive nephrotoxicity: tacrolimus causes afferent arteriolar vasoconstriction while polymyxin B causes direct tubular injury.
What to do
Use only when no alternative exists, and monitor serum creatinine and tacrolimus trough levels closely. Reduce the tacrolimus dose or adjust polymyxin B for renal function as needed.
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 Tacrolimus
- Adenovirus types 4 and 7 live + Tacrolimus Contraindicated
- Bcg vaccine live + Tacrolimus Contraindicated
- Cidofovir + Tacrolimus Contraindicated
- Cyclosporin + Tacrolimus Contraindicated
- Influenza virus vaccine quadrivalent intranasal + Tacrolimus Contraindicated
- Measles mumps and rubella vaccine live + Tacrolimus Contraindicated
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 Tacrolimus?
MediHelp rates the interaction as major. Polymyxin b and Tacrolimus 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. Both drugs are nephrotoxic, and combined use raises the risk of acute kidney injury. Polymyxin B also carries neurotoxic and ototoxic potential, and accumulation from reduced renal function can worsen these effects.
How serious is the interaction between Polymyxin b and Tacrolimus?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Use only when no alternative exists, and monitor serum creatinine and tacrolimus trough levels closely. Reduce the tacrolimus dose or adjust polymyxin B for renal function as needed.
What other medicines interact with Tacrolimus?
MediHelp also lists interactions of Tacrolimus with, for example, Adenovirus types 4 and 7 live, Bcg vaccine live, Cidofovir. The full list is on the Tacrolimus page.
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