Drug interactions
Phenytoin + Rocuronium
Severity: Moderate
Phenytoin and Rocuronium: moderate 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
Patients on long-term phenytoin often show resistance to rocuronium, with a shorter duration of blockade and higher infusion needs. Acute phenytoin exposure may instead potentiate blockade.
What this interaction means in plain words
Phenytoin and Rocuronium can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Phenytoin belongs to Central Nervous System; Rocuronium belongs to Musculoskeletal.
Why it happens
Chronic phenytoin likely induces hepatic metabolism and alters neuromuscular receptor sensitivity, reducing rocuronium effect.
What to do
Monitor neuromuscular function with train-of-four and anticipate higher or more frequent rocuronium doses in chronic phenytoin users. Ensure full recovery before extubation.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Rocuronium
Other interactions of Phenytoin
- Artemether / lumefantrine + Phenytoin Contraindicated
- Bictegravir + Phenytoin Contraindicated
- Cabotegravir + Phenytoin Contraindicated
- Doravirine + Phenytoin Contraindicated
- Elbasvir / grazoprevir + Phenytoin Contraindicated
- Elvitegravir / cobicistat / emtricitabine / tenofovir df + Phenytoin Contraindicated
Frequently asked questions
Can I take Phenytoin with Rocuronium?
MediHelp rates the interaction as moderate. Phenytoin and Rocuronium can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Patients on long-term phenytoin often show resistance to rocuronium, with a shorter duration of blockade and higher infusion needs. Acute phenytoin exposure may instead potentiate blockade.
How serious is the interaction between Phenytoin and Rocuronium?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor neuromuscular function with train-of-four and anticipate higher or more frequent rocuronium doses in chronic phenytoin users. Ensure full recovery before extubation.
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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