Drug interactions
Brexpiprazole + Phenobarbital
Severity: Major
Brexpiprazole and Phenobarbital: major interaction.
Last updated Sources: US FDA label
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
Phenobarbital is a strong CYP3A4 inducer that can markedly reduce brexpiprazole exposure and may cause relapse of symptoms. The two drugs also both cause sedation, which may be additive.
What this interaction means in plain words
Brexpiprazole and Phenobarbital can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Why it happens
Induction of CYP3A4 by phenobarbital increases brexpiprazole metabolism, plus additive CNS depression.
What to do
Double the brexpiprazole dose over 1 to 2 weeks when phenobarbital is used, and monitor clinical response. Return to the usual dose over 1 to 2 weeks after phenobarbital is stopped, and monitor sedation.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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References
Other interactions of Brexpiprazole
Frequently asked questions
Can I take Brexpiprazole with Phenobarbital?
MediHelp rates the interaction as major. Brexpiprazole and Phenobarbital can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Phenobarbital is a strong CYP3A4 inducer that can markedly reduce brexpiprazole exposure and may cause relapse of symptoms. The two drugs also both cause sedation, which may be additive.
How serious is the interaction between Brexpiprazole and Phenobarbital?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Double the brexpiprazole dose over 1 to 2 weeks when phenobarbital is used, and monitor clinical response. Return to the usual dose over 1 to 2 weeks after phenobarbital is stopped, and monitor sedation.
What other medicines interact with Brexpiprazole?
MediHelp also lists interactions of Brexpiprazole with, for example, Alfentanil, Amisulpride, Apalutamide. The full list is on the Brexpiprazole page.
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