Drug interactions
Efavirenz + Fluphenazine
Severity: Moderate
Efavirenz and Fluphenazine: 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
Efavirenz and fluphenazine can each prolong the QT interval, so together they may increase the risk of serious ventricular arrhythmia. Risk rises in patients with cardiac disease or electrolyte disturbances.
What this interaction means in plain words
Efavirenz and Fluphenazine 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; Fluphenazine belongs to Central Nervous System.
Why it happens
Additive QT prolongation; efavirenz may also affect antipsychotic exposure through enzyme induction.
What to do
Check a baseline ECG and electrolytes and repeat after dose changes. Avoid adding further QT-prolonging drugs.
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 Fluphenazine
- Arsenic trioxide + Fluphenazine Contraindicated
- Dofetilide + Fluphenazine Contraindicated
- Fluphenazine + Ibutilide Contraindicated
- Fluphenazine + Pimozide Contraindicated
- Adagrasib + Fluphenazine Major
- Alfentanil + Fluphenazine Major
Frequently asked questions
Can I take Efavirenz with Fluphenazine?
MediHelp rates the interaction as moderate. Efavirenz and Fluphenazine 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 and fluphenazine can each prolong the QT interval, so together they may increase the risk of serious ventricular arrhythmia. Risk rises in patients with cardiac disease or electrolyte disturbances.
How serious is the interaction between Efavirenz and Fluphenazine?
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 and repeat after dose changes. Avoid adding further QT-prolonging drugs.
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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