Drug interactions
Methocarbamol + OnabotulinumtoxinA
Severity: Moderate
Methocarbamol and OnabotulinumtoxinA: 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
Drugs that reduce muscle tone may add to the neuromuscular weakness produced by botulinum toxin. This could increase the risk of excessive weakness, and in rare cases of toxin spread, swallowing or breathing difficulty.
What this interaction means in plain words
Methocarbamol and OnabotulinumtoxinA 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.
Methocarbamol belongs to Musculoskeletal; OnabotulinumtoxinA belongs to Musculoskeletal.
Why it happens
Pharmacodynamic synergism, as botulinum toxin blocks acetylcholine release while methocarbamol reduces muscle tone through central depression.
What to do
Monitor for excessive muscle weakness, dysphagia or respiratory symptoms after injection. Consider reducing or temporarily withholding methocarbamol if weakness is more pronounced than intended.
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 Methocarbamol and OnabotulinumtoxinA, 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 Methocarbamol
Other interactions of OnabotulinumtoxinA
Frequently asked questions
Can I take Methocarbamol with OnabotulinumtoxinA?
MediHelp rates the interaction as moderate. Methocarbamol and OnabotulinumtoxinA 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. Drugs that reduce muscle tone may add to the neuromuscular weakness produced by botulinum toxin. This could increase the risk of excessive weakness, and in rare cases of toxin spread, swallowing or breathing difficulty.
How serious is the interaction between Methocarbamol and OnabotulinumtoxinA?
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 for excessive muscle weakness, dysphagia or respiratory symptoms after injection. Consider reducing or temporarily withholding methocarbamol if weakness is more pronounced than intended.
What other medicines interact with Methocarbamol?
MediHelp also lists interactions of Methocarbamol with, for example, Alfentanil, Amobarbital, Belladonna and opium. The full list is on the Methocarbamol 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.
