Drug interactions
Fosphenytoin + Rocuronium
Severity: Moderate
Fosphenytoin 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 or fosphenytoin often show resistance to non-depolarizing neuromuscular blockers such as rocuronium. Onset may be unchanged but the block is shorter and higher doses or more frequent dosing may be needed.
What this interaction means in plain words
Fosphenytoin 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.
Fosphenytoin belongs to Central Nervous System; Rocuronium belongs to Musculoskeletal.
Why it happens
Chronic anticonvulsant exposure causes resistance, probably via increased hepatic clearance and altered neuromuscular receptor sensitivity.
What to do
Monitor neuromuscular blockade with train-of-four and titrate rocuronium to effect, expecting higher infusion requirements. Be prepared for faster recovery than usual.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Fosphenytoin and Rocuronium, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
Other interactions of Rocuronium
Other interactions of Fosphenytoin
- Dronedarone + Fosphenytoin Contraindicated
- Fosphenytoin + Ledipasvir-sofosbuvir Contraindicated
- Fosphenytoin + Lorlatinib Contraindicated
- Fosphenytoin + Lurasidone Contraindicated
- Fosphenytoin + Ranolazine Contraindicated
- Fosphenytoin + Sofosbuvir-velpatasvir-voxilaprevir Contraindicated
Frequently asked questions
Can I take Fosphenytoin with Rocuronium?
MediHelp rates the interaction as moderate. Fosphenytoin 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 or fosphenytoin often show resistance to non-depolarizing neuromuscular blockers such as rocuronium. Onset may be unchanged but the block is shorter and higher doses or more frequent dosing may be needed.
How serious is the interaction between Fosphenytoin 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 blockade with train-of-four and titrate rocuronium to effect, expecting higher infusion requirements. Be prepared for faster recovery than usual.
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.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
