Drug interactions
Efavirenz + Zaleplon
Severity: Minor
Efavirenz and Zaleplon: minor 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 may reduce zaleplon concentrations, which may lessen its hypnotic effect. Zaleplon is mainly metabolized by aldehyde oxidase, with CYP3A4 playing a secondary role, so the effect is expected to be small. Both drugs can cause CNS effects.
What this interaction means in plain words
Efavirenz and Zaleplon have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Efavirenz belongs to Anti Virals; Zaleplon belongs to Central Nervous System.
Why it happens
Efavirenz induces CYP3A4, a secondary pathway for zaleplon metabolism.
What to do
No dose adjustment is generally needed. Reassess hypnotic response and counsel on additive drowsiness.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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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 Zaleplon
- Calcium / magnesium / potassium / sodium oxybates + Zaleplon Contraindicated
- Sodium oxybate + Zaleplon Contraindicated
- Brexanolone + Zaleplon Major
- Buprenorphine long-acting + Zaleplon Major
- Buprenorphine subdermal implant + Zaleplon Major
- Buprenorphine transdermal + Zaleplon Major
Frequently asked questions
Can I take Efavirenz with Zaleplon?
MediHelp rates the interaction as minor. Efavirenz and Zaleplon have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Efavirenz may reduce zaleplon concentrations, which may lessen its hypnotic effect. Zaleplon is mainly metabolized by aldehyde oxidase, with CYP3A4 playing a secondary role, so the effect is expected to be small. Both drugs can cause CNS effects.
How serious is the interaction between Efavirenz and Zaleplon?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: No dose adjustment is generally needed. Reassess hypnotic response and counsel on additive drowsiness.
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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