Haloperidol (Haldol)

Raw research findings for this medication. Mostly single studies, not curated or confirmed robust.

About Haloperidol

What it is

Haloperidol is an older, first-generation antipsychotic that strongly blocks dopamine D2 receptors. It is used for schizophrenia, acute agitation and delirium, severe tics in Tourette's syndrome, and nausea in palliative care. It is sold as Haldol, among other names, also as a long-acting injection.

How genes come into it

Haloperidol is broken down by the liver enzymes CYP3A4 and CYP2D6. People with no working CYP2D6 copies (poor metabolizers) have higher levels, which studies link to more movement side effects such as stiffness and tremor; people with extra copies have lower levels. DPWG has published a guideline on CYP2D6 and haloperidol. Studies have also looked at CYP3A4 and dopamine-related genes, with weaker evidence.

Published guidelines

Clinical guidelines that name a gene for Haloperidol. They sort people into groups by the gene copies they carry.

DPWG guideline: CYP2D6. CYP2D6 activity score 0 to 6 or more. 2024.

What research found

Every published finding on gene variants and Haloperidol. Upload your DNA file to see which of these rows apply to you.

Rated evidence (10 rated variants)

PharmGKB weighs all studies of a variant and rates how strong the evidence is, from 1A (strongest) to 4.

CYP2D6 CYP2D6*1, CYP2D6*2, CYP2D6*3, CYP2D6*4, CYP2D6*5, CYP2D6*10, CYP2D6*17: Level 1A · replicated. Metabolism/PK: Schizophrenia. 14.

FAAH rs324420: Level 3. Toxicity: Psychotic Disorder. 2.

SLC6A5 rs2298826: Level 3. Toxicity: Schizophrenia. 1.

EPM2A rs1415744: Level 3. Efficacy: Schizophrenia. 1.

Metabolism (22 findings)

Studies of how quickly the body processes this medication.

CYP2D6 CYP2D6 poor metabolizer genotype: CYP2D6 poor metabolizer is associated with increased dose-adjusted trough concentrations of haloperidol in people with Psychotic Disorders as compared to CYP2D6 normal metabolizer.

CYP2D6 CYP2D6*1, CYP2D6*10: CYP2D6 *10 is associated with decreased metabolism of haloperidol in people with Schizophrenia as compared to CYP2D6 *1.

CYP2D6 CYP2D6*1, CYP2D6*10: CYP2D6 *10 is associated with decreased metabolism of haloperidol in people with Schizophrenia as compared to CYP2D6 *1.

CYP2D6 CYP2D6*1, CYP2D6*10: CYP2D6 *10 is associated with decreased metabolism of haloperidol in people with Schizophrenia as compared to CYP2D6 *1.

Response (12 findings)

Studies of how well it worked in people carrying a variant.

CYP2D6 rs3892097: Genotype CC is associated with decreased response to haloperidol in men with Alcohol-Related Disorders, Alcoholic psychosis NOS and Alcoholism as compared to genotype CT.

CYP3A43 rs680055: Genotype CG is associated with increased response to antipsychotics, aripiprazole, clozapine, haloperidol, olanzapine, quetiapine or risperidone in people with schizoaffective disorder or Schizophrenia as compared to genotype CC.

DRD2 rs1799978: Allele C is associated with increased resistance to haloperidol, olanzapine, perphenazine, quetiapine or risperidone in people with Schizophrenia as compared to allele T.

EPM2A rs1415744: Allele C is associated with increased response to chlorpromazine, clozapine, haloperidol, olanzapine, quetiapine, risperidone or trifluoperazine in people with Schizophrenia as compared to allele T.

Dosing (1 finding)

Studies of how much of the drug people needed or tolerated.

CYP3A4 CYP3A4*1, CYP3A4*22: CYP3A4 *22 is not associated with dose of aripiprazole, haloperidol, pimozide or risperidone in people with Psychotic Disorders as compared to CYP3A4 *1/*1.

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.

Related Drugs

More drugs from the same category

Abilify (Antipsychotics)

Antipsychotics (class) (Antipsychotics)

Bromperidol (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.

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Content updated September 2026.

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