Drug interactions
Carbamazepine + Oxybutynin
Severity: Minor
Carbamazepine and Oxybutynin: minor 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
Carbamazepine induces CYP3A4 and can lower oxybutynin concentrations, possibly reducing bladder symptom control. The reverse effect of oxybutynin on carbamazepine levels is not established.
What this interaction means in plain words
Carbamazepine and Oxybutynin have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Carbamazepine belongs to Central Nervous System; Oxybutynin belongs to Genitourinary.
Why it happens
Carbamazepine induces CYP3A4, increasing oxybutynin metabolism.
What to do
Assess clinical response to oxybutynin and increase the dose or change therapy if control is inadequate. Routine carbamazepine level monitoring is not required unless toxicity is suspected.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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Other interactions of Oxybutynin
Other interactions of Carbamazepine
- Artemether / lumefantrine + Carbamazepine Contraindicated
- Cabotegravir + Carbamazepine Contraindicated
- Carbamazepine + Delamanid Contraindicated
- Carbamazepine + Dienogest / estradiol valerate Contraindicated
- Carbamazepine + Doravirine Contraindicated
- Carbamazepine + Elbasvir / grazoprevir Contraindicated
Frequently asked questions
Can I take Carbamazepine with Oxybutynin?
MediHelp rates the interaction as minor. Carbamazepine and Oxybutynin have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Carbamazepine induces CYP3A4 and can lower oxybutynin concentrations, possibly reducing bladder symptom control. The reverse effect of oxybutynin on carbamazepine levels is not established.
How serious is the interaction between Carbamazepine and Oxybutynin?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Assess clinical response to oxybutynin and increase the dose or change therapy if control is inadequate. Routine carbamazepine level monitoring is not required unless toxicity is suspected.
What other medicines interact with Oxybutynin?
MediHelp also lists interactions of Oxybutynin with, for example, Bethanechol, Clozapine, Potassium chloride. The full list is on the Oxybutynin page.
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