Drug interactions
Efavirenz + Nortriptyline
Severity: Moderate
Efavirenz and Nortriptyline: 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 drugs can prolong the QT interval, so combined use may increase the risk of arrhythmia, particularly torsades de pointes, in susceptible patients. Efavirenz may also alter tricyclic levels through CYP effects.
What this interaction means in plain words
Efavirenz and Nortriptyline 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; Nortriptyline belongs to Central Nervous System.
Why it happens
Additive QT prolongation, with possible pharmacokinetic changes via CYP2D6/CYP3A4.
What to do
Obtain a baseline ECG and correct potassium and magnesium abnormalities. Monitor QTc and consider nortriptyline levels or clinical response.
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 Nortriptyline
- Disopyramide + Nortriptyline Contraindicated
- Dofetilide + Nortriptyline Contraindicated
- Dronedarone + Nortriptyline Contraindicated
- Ibutilide + Nortriptyline Contraindicated
- Isocarboxazid + Nortriptyline Contraindicated
- Methylene blue + Nortriptyline Contraindicated
Frequently asked questions
Can I take Efavirenz with Nortriptyline?
MediHelp rates the interaction as moderate. Efavirenz and Nortriptyline 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 drugs can prolong the QT interval, so combined use may increase the risk of arrhythmia, particularly torsades de pointes, in susceptible patients. Efavirenz may also alter tricyclic levels through CYP effects.
How serious is the interaction between Efavirenz and Nortriptyline?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Obtain a baseline ECG and correct potassium and magnesium abnormalities. Monitor QTc and consider nortriptyline levels or clinical response.
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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