Drug interactions
Efavirenz + Valbenazine
Severity: Moderate
Efavirenz and Valbenazine: 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
Valbenazine can prolong the QT interval at higher exposures, and efavirenz has a similar liability. Efavirenz is also a CYP3A4 inducer that can lower the exposure of valbenazine and its active metabolite.
What this interaction means in plain words
Efavirenz and Valbenazine 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.
Efavirenz belongs to Anti Virals; Valbenazine belongs to Central Nervous System.
Why it happens
Additive QT prolongation, plus CYP3A4 induction by efavirenz reducing valbenazine exposure.
What to do
Avoid coadministration with strong CYP3A4 inducers where possible, as the valbenazine label advises against it. If used together, monitor efficacy and ECG, particularly with other QT risk factors.
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 Efavirenz
- Cobimetinib + Efavirenz Contraindicated
- Dienogest / estradiol valerate + Efavirenz Contraindicated
- Dihydroergotamine intranasal + Efavirenz Contraindicated
- Dihydroergotamine + Efavirenz Contraindicated
- Doravirine + Efavirenz Contraindicated
- Efavirenz + Elbasvir / grazoprevir Contraindicated
Other interactions of Valbenazine
- Deutetrabenazine + Valbenazine Contraindicated
- Tranylcypromine + Valbenazine Contraindicated
- Amiodarone + Valbenazine Major
- Amisulpride + Valbenazine Major
- Apalutamide + Valbenazine Major
- Carbamazepine + Valbenazine Major
Frequently asked questions
Can I take Efavirenz with Valbenazine?
MediHelp rates the interaction as moderate. Efavirenz and Valbenazine 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. Valbenazine can prolong the QT interval at higher exposures, and efavirenz has a similar liability. Efavirenz is also a CYP3A4 inducer that can lower the exposure of valbenazine and its active metabolite.
How serious is the interaction between Efavirenz and Valbenazine?
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 coadministration with strong CYP3A4 inducers where possible, as the valbenazine label advises against it. If used together, monitor efficacy and ECG, particularly with other QT risk factors.
What other medicines interact with Efavirenz?
MediHelp also lists interactions of Efavirenz with, for example, Cobimetinib, Dienogest / estradiol valerate, Dihydroergotamine intranasal. The full list is on the Efavirenz page.
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