Drug interactions
Efavirenz + Risperidone
Severity: Moderate
Efavirenz and Risperidone: 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
Both agents have been associated with QT prolongation, so combined use may add to arrhythmic risk. Efavirenz may also modestly lower risperidone levels.
What this interaction means in plain words
Efavirenz and Risperidone 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; Risperidone belongs to Central Nervous System.
Why it happens
Additive QT prolongation and possible efavirenz induction of risperidone metabolism.
What to do
Check a baseline ECG and electrolytes, especially in patients with other risk factors. Monitor psychiatric response and adjust the risperidone dose if needed.
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 Risperidone
- Ibutilide + Risperidone Contraindicated
- Risperidone + Vandetanib Contraindicated
- Adagrasib + Risperidone Major
- Amiodarone + Risperidone Major
- Amisulpride + Risperidone Major
- Amoxapine + Risperidone Major
Frequently asked questions
Can I take Efavirenz with Risperidone?
MediHelp rates the interaction as moderate. Efavirenz and Risperidone 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. Both agents have been associated with QT prolongation, so combined use may add to arrhythmic risk. Efavirenz may also modestly lower risperidone levels.
How serious is the interaction between Efavirenz and Risperidone?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Check a baseline ECG and electrolytes, especially in patients with other risk factors. Monitor psychiatric response and adjust the risperidone dose if needed.
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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