Drug interactions
Efavirenz + Thiothixene
Severity: Major
Efavirenz and Thiothixene: major 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 drugs have the potential to prolong the QT interval, increasing the risk of ventricular arrhythmias including torsades de pointes. The risk is higher with electrolyte disturbance or heart disease.
What this interaction means in plain words
Efavirenz and Thiothixene can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Why it happens
Additive pharmacodynamic QT interval prolongation.
What to do
Obtain a baseline ECG, correct hypokalemia and hypomagnesemia, and monitor QTc; consider an alternative antipsychotic with lower QT liability.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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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
Frequently asked questions
Can I take Efavirenz with Thiothixene?
MediHelp rates the interaction as major. Efavirenz and Thiothixene can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Both drugs have the potential to prolong the QT interval, increasing the risk of ventricular arrhythmias including torsades de pointes. The risk is higher with electrolyte disturbance or heart disease.
How serious is the interaction between Efavirenz and Thiothixene?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Obtain a baseline ECG, correct hypokalemia and hypomagnesemia, and monitor QTc; consider an alternative antipsychotic with lower QT liability.
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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