Drug interactions
Orphenadrin + Pyridostigmine
Severity: Moderate
Orphenadrin and Pyridostigmine: 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
Orphenadrine is an anticholinergic and can oppose the cholinergic benefit of pyridostigmine in myasthenia gravis. Orphenadrine has also been reported to worsen muscle weakness in myasthenic patients, so symptom control may be lost.
What this interaction means in plain words
Orphenadrin and Pyridostigmine 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.
Orphenadrin belongs to Musculoskeletal; Pyridostigmine belongs to Central Nervous System.
Why it happens
Pharmacodynamic antagonism between muscarinic blockade and cholinesterase inhibition.
What to do
Avoid orphenadrine in myasthenia gravis where possible and choose a different muscle relaxant. If both are given, watch for worsening weakness and review the pyridostigmine dose.
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 Orphenadrin
Other interactions of Pyridostigmine
Frequently asked questions
Can I take Orphenadrin with Pyridostigmine?
MediHelp rates the interaction as moderate. Orphenadrin and Pyridostigmine 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. Orphenadrine is an anticholinergic and can oppose the cholinergic benefit of pyridostigmine in myasthenia gravis. Orphenadrine has also been reported to worsen muscle weakness in myasthenic patients, so symptom control may be lost.
How serious is the interaction between Orphenadrin and Pyridostigmine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid orphenadrine in myasthenia gravis where possible and choose a different muscle relaxant. If both are given, watch for worsening weakness and review the pyridostigmine dose.
What other medicines interact with Orphenadrin?
MediHelp also lists interactions of Orphenadrin with, for example, Alfentanil, Amobarbital, Benzhydrocodone / acetaminophen. The full list is on the Orphenadrin page.
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