Drug interactions
Flavoxate + Physostigmine
Severity: Moderate
Flavoxate and Physostigmine: 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
Physostigmine inhibits acetylcholinesterase and raises acetylcholine, which pharmacologically opposes flavoxate's antimuscarinic effects. Physostigmine is used to reverse anticholinergic toxicity, so flavoxate's effect may be reduced.
What this interaction means in plain words
Flavoxate and Physostigmine 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.
Why it happens
Pharmacodynamic antagonism between a cholinesterase inhibitor and a muscarinic antagonist.
What to do
Expect reduced effect of one or both agents; this is intended when treating anticholinergic toxicity. Monitor heart rate and for cholinergic effects such as bradycardia and bronchospasm.
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 Flavoxate and Physostigmine, 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 Flavoxate
- Clozapine + Flavoxate Major
- Abobotulinumtoxina + Flavoxate Moderate
- Aclidinium + Flavoxate Moderate
- Amantadine + Flavoxate Moderate
- Amitriptyline + Flavoxate Moderate
- Amoxapine + Flavoxate Moderate
Frequently asked questions
Can I take Flavoxate with Physostigmine?
MediHelp rates the interaction as moderate. Flavoxate and Physostigmine 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. Physostigmine inhibits acetylcholinesterase and raises acetylcholine, which pharmacologically opposes flavoxate's antimuscarinic effects. Physostigmine is used to reverse anticholinergic toxicity, so flavoxate's effect may be reduced.
How serious is the interaction between Flavoxate and Physostigmine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Expect reduced effect of one or both agents; this is intended when treating anticholinergic toxicity. Monitor heart rate and for cholinergic effects such as bradycardia and bronchospasm.
What other medicines interact with Flavoxate?
MediHelp also lists interactions of Flavoxate with, for example, Clozapine, Abobotulinumtoxina, Aclidinium. The full list is on the Flavoxate 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.
