Drug interactions
Efavirenz + Fesoterodine
Severity: Minor
Efavirenz and Fesoterodine: 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
Efavirenz induces CYP3A4 and may lower exposure to the active metabolite of fesoterodine. This could reduce efficacy for overactive bladder symptoms.
What this interaction means in plain words
Efavirenz and Fesoterodine have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Efavirenz belongs to Anti Virals; Fesoterodine belongs to Genitourinary.
Why it happens
Efavirenz induces CYP3A4, increasing clearance of the active fesoterodine metabolite.
What to do
No empirical adjustment; evaluate symptom control and titrate fesoterodine within the labeled dose range if needed.
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 Fesoterodine
Other interactions of Efavirenz
- Cobimetinib + Efavirenz Contraindicated
- Dienogest / estradiol valerate + Efavirenz Contraindicated
- Dihydroergotamine intranasal + Efavirenz Contraindicated
- Dihydroergotamine + Efavirenz Contraindicated
- Doravirine + Efavirenz Contraindicated
- Efavirenz + Elbasvir / grazoprevir Contraindicated
Frequently asked questions
Can I take Efavirenz with Fesoterodine?
MediHelp rates the interaction as minor. Efavirenz and Fesoterodine have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Efavirenz induces CYP3A4 and may lower exposure to the active metabolite of fesoterodine. This could reduce efficacy for overactive bladder symptoms.
How serious is the interaction between Efavirenz and Fesoterodine?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: No empirical adjustment; evaluate symptom control and titrate fesoterodine within the labeled dose range if needed.
What other medicines interact with Fesoterodine?
MediHelp also lists interactions of Fesoterodine with, for example, Bethanechol, Clozapine, Levoketoconazole. The full list is on the Fesoterodine page.
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