Drug interactions
Efavirenz + Secobarbital
Severity: Moderate
Efavirenz and Secobarbital: 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
Barbiturates are enzyme inducers and may lower efavirenz concentrations, risking reduced antiviral efficacy. Both drugs also cause CNS effects such as sedation and dizziness, which may be additive.
What this interaction means in plain words
Efavirenz and Secobarbital 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; Secobarbital belongs to Central Nervous System.
Why it happens
Secobarbital induces CYP3A4 and CYP2B6, increasing efavirenz clearance, and both drugs cause additive CNS depression.
What to do
Avoid long-term combined use where possible. If it is necessary, monitor HIV viral load and consider efavirenz levels, and counsel the patient about sedation.
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 Secobarbital
- Calcium / magnesium / potassium / sodium oxybates + Secobarbital Contraindicated
- Doravirine + Secobarbital Contraindicated
- Elbasvir / grazoprevir + Secobarbital Contraindicated
- Elvitegravir / cobicistat / emtricitabine / tenofovir df + Secobarbital Contraindicated
- Isavuconazonium + Secobarbital Contraindicated
- Lonafarnib + Secobarbital Contraindicated
Frequently asked questions
Can I take Efavirenz with Secobarbital?
MediHelp rates the interaction as moderate. Efavirenz and Secobarbital 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. Barbiturates are enzyme inducers and may lower efavirenz concentrations, risking reduced antiviral efficacy. Both drugs also cause CNS effects such as sedation and dizziness, which may be additive.
How serious is the interaction between Efavirenz and Secobarbital?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid long-term combined use where possible. If it is necessary, monitor HIV viral load and consider efavirenz levels, and counsel the patient about sedation.
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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