Paroxetine and Pimozide interaction
Paroxetine and Pimozide: 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 Paroxetine (PAROXETINE HYDROCHLORIDE) label · effective 2026-09-16
Paroxetine HCL CR should not be used in patients receiving medications that can prolong QT interval and are also metabolized by CYP450 2D6,such as thioridazine or pimozide [see Drug Interactions (7),Warnings and Precautions (5.3)].
Concomitant use of pimozide or thioridazine.
Since thioridazine and pimozide given alone produce prolongation of the QTc interval and increase the risk of serious ventricular arrhythmias, the use of Paroxetine HCL CR is contraindicated in combination with thioridazine and pimozide [see Contraindications ( 4 ), Drug Interactions ( 7 ), Clinical Pharmacology ( 12.3 )].
Examples selegiline, tranylcypromine, isocarboxazid, phenelzine, linezolid, methylene blue Pimozide and Thioridazine Clinical Impact Paroxetine HCL CR should not be used in patients receiving medications that can prolong QT interval and are metabolized by CYP450 2D6 such as thioridazine or pimozide (see Contraindications and Warnings and Precautions ) Intervention…
The CYP2D6 inhibitory properties of paroxetine can elevate plasma levels of thioridazine and pimozide.
From the Pimozide label · effective 2026-08-12
Concomitant use of pimozide with paroxetine and other strong CYP 2D6 inhibitors is contraindicated (See PRECAUTIONS – DRUG INTERACTIONS ).
Concomitant use of pimozide and paroxetine or other strong CYP 2D6 inhibitors are contraindicated (see CONTRAINDICATIONS ).
The increase in pimozide AUC and C max is related to the CYP 2D6 inhibitory properties of paroxetine.
Other important considerations in the differential diagnosis include central anticholinergic toxicity, heat stroke, drug fever and primary central nervous system (CNS) pathology.
DRUG INTERACTIONS Because pimozide prolongs the QT interval of the electrocardiogram, an additive effect on QT interval would be anticipated if administered with other drugs, such as phenothiazines, tricyclic antidepressants or antiarrhythmic agents, which prolong the QT interval.
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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.