Phenobarbital and Pitolisant interaction
Phenobarbital and Pitolisant: 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
Drugs that Prolong the QT Interval : Avoid concomitant use.
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)] .
Other products that may also prolong the QTc interval may have additive effects, and products that may increase concentrations of phenobarbital [see Drug Interactions (7.1)] may increase the QT prolongation risk; therefore, avoid concomitant use of SEZABY and these products.
From the Pitolisant (Wakix) label · effective 2026-02-13
Strong CYP3A4 Inducers: Decreased exposure of WAKIX; consider dosage adjustment of WAKIX ( 2.6 , 7.1 )
Strong CYP3A4 Inducers Clinical Implication: Concomitant use of WAKIX with strong CYP3A4 inducers decreases exposure of pitolisant by 50%.
If concomitant dosing of a strong CYP3A4 inducer is discontinued, decrease WAKIX dosage by half [see see Dosage and Administration ( 2.6 ), Clinical Pharmacology ( 12.3 )] .
Prevention or Management: Assess for loss of efficacy after initiation of a strong CYP3A4 inducer.
Effect of WAKIX on Other Drugs Sensitive CYP3A4 Substrates Clinical Implication: WAKIX is a borderline/weak inducer of CYP3A4.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
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.