Phenobarbital and Pimavanserin interaction
Phenobarbital and Pimavanserin: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Phenobarbital (SEZABY) label · effective 2025-12-23
CNS depressants: Closely monitor for sedation and respiratory depression.
Drugs that Prolong the QT Interval : Avoid concomitant use.
CNS Depressants Closely monitor for signs of sedation and respiratory depression with concomitant use of SEZABY with other CNS depressants, including opioids [see Warnings and Precautions (5.1)] .
QT Prolongation SEZABY may prolong the QT interval [see Clinical Pharmacology (12.2)] .
Drugs that Prolong QT Interval SEZABY may prolong the QT interval [see Warnings and Precautions (5.10) and Clinical Pharmacology (12.2)] .
From the Pimavanserin (NUPLAZID) label · effective 2026-06-18
Strong or Moderate CYP3A4 Inducers: Avoid concomitant use of NUPLAZID.
Intervention: Avoid concomitant use of strong or moderate CYP3A4 inducers with NUPLAZID [see Dosage and Administration (2.3) ] .
Strong or Moderate CYP3A4 Inducers Clinical Impact: Concomitant use of NUPLAZID with strong or moderate CYP3A4 inducers reduces pimavanserin exposure [see Clinical Pharmacology (12.3) ].
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Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.