Raw research findings for this medication. Mostly single studies, not curated or confirmed robust.
Perphenazine is a medium-potency phenothiazine antipsychotic that blocks dopamine D2 receptors. It is used for schizophrenia and for severe nausea and vomiting, and combined with amitriptyline for depression with anxiety. In the large CATIE trial it did about as well as several newer antipsychotics. It is sold as Trilafon, among other names.
Perphenazine is broken down mainly by CYP2D6, and poor metabolizers reach higher levels with more side effects, which the US FDA lists as affecting safety. Most other gene studies on it come from the CATIE trial and flagged genes such as RELN and RGS4 for response; none has been confirmed. There is no CPIC or DPWG guideline.
Clinical guidelines that name a gene for Perphenazine. They sort people into groups by the gene copies they carry.
Every published finding on gene variants and Perphenazine. Upload your DNA file to see which of these rows apply to you.
PharmGKB weighs all studies of a variant and rates how strong the evidence is, from 1A (strongest) to 4.
RGS4 rs951439: Level 3. Efficacy: Schizophrenia. 1.
RGS4 rs2842030: Level 3. Efficacy: Schizophrenia. 1.
Studies of how quickly the body processes this medication.
CYP2D6 CYP2D6*7: CYP2D6 *7/*7 is associated with decreased metabolism of perphenazine.
Studies of how well it worked in people carrying a variant.
rs11774231: Allele C is associated with response to perphenazine in people with Schizophrenia.
CDH13 rs2116971: Allele G is associated with response to perphenazine in people with Schizophrenia.
MAML3 rs11100483: Allele A is associated with response to perphenazine in people with Schizophrenia.
Study findings and evidence levels: PharmGKB (CC BY-SA 4.0). Guidelines: CPIC and DPWG, as bundled in PharmCAT. Most studies were done mainly in people of European ancestry.
More drugs from the same category
Antipsychotics (class) (Antipsychotics)
Not a prescribing recommendation. This page is educational information about pharmacogenomic research and clinical guidelines - it is not medical or dosing advice, and not a prediction of how any medication will work for you. Never start, stop, or change a medication or dose based on it; talk to your doctor or pharmacist, who can order clinical-grade testing if appropriate.
Content updated September 2026.
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