Drug interactions
Asenapine transdermal + Efavirenz
Severity: Moderate
Asenapine transdermal and Efavirenz: 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 QTc interval, so combining them may increase the risk of serious ventricular arrhythmias, particularly with other risk factors.
What this interaction means in plain words
Asenapine transdermal and Efavirenz 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.
Why it happens
Additive QT interval prolongation.
What to do
Obtain a baseline ECG, correct potassium and magnesium, and monitor the QTc during therapy. Choose an alternative if QTc becomes significantly prolonged.
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
Frequently asked questions
Can I take Asenapine transdermal with Efavirenz?
MediHelp rates the interaction as moderate. Asenapine transdermal and Efavirenz 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 QTc interval, so combining them may increase the risk of serious ventricular arrhythmias, particularly with other risk factors.
How serious is the interaction between Asenapine transdermal and Efavirenz?
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, correct potassium and magnesium, and monitor the QTc during therapy. Choose an alternative if QTc becomes significantly prolonged.
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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