Drug interactions
Guanfacine + Secobarbital
Severity: Moderate
Guanfacine 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 induce CYP3A4, which is the main metabolic pathway of guanfacine, so guanfacine exposure and half-life fall. This can lead to loss of blood pressure or ADHD symptom control.
What this interaction means in plain words
Guanfacine 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.
Guanfacine belongs to Cardiovascular; Secobarbital belongs to Central Nervous System.
Why it happens
Induction of CYP3A4 by secobarbital increases guanfacine clearance.
What to do
Monitor blood pressure or ADHD response and increase the guanfacine dose if needed (the extended-release label suggests considering doubling the dose with strong or moderate inducers). Reduce the dose again if the barbiturate is stopped.
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 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
Other interactions of Guanfacine
- Clonidine + Guanfacine Major
- Guanfacine + Lofexidine Major
- Aldesleukin + Guanfacine Moderate
- Amiodarone + Guanfacine Moderate
- Amisulpride + Guanfacine Moderate
- Amitriptyline + Guanfacine Moderate
Frequently asked questions
Can I take Guanfacine with Secobarbital?
MediHelp rates the interaction as moderate. Guanfacine 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 induce CYP3A4, which is the main metabolic pathway of guanfacine, so guanfacine exposure and half-life fall. This can lead to loss of blood pressure or ADHD symptom control.
How serious is the interaction between Guanfacine 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: Monitor blood pressure or ADHD response and increase the guanfacine dose if needed (the extended-release label suggests considering doubling the dose with strong or moderate inducers). Reduce the dose again if the barbiturate is stopped.
What other medicines interact with Secobarbital?
MediHelp also lists interactions of Secobarbital with, for example, Calcium / magnesium / potassium / sodium oxybates, Doravirine, Elbasvir / grazoprevir. The full list is on the Secobarbital page.
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