Is Haldol affected by genetics?
Yes. Its active ingredient has published pharmacogenetic guidance for a gene that varies between people.
Haldol is affected by pharmacogenetics through the CYP2D6 gene. Your genotype for this gene can change how well Haldol works for you or how well you tolerate it. The strongest evidence level on this page is Moderate, from the published guidelines shown below.
What's in Haldol
Haloperidol Affected by CYP2D6
Affected by CYP2D6. Guidance from DPWG, moderate evidence.
Read the full haloperidol genetics guideHaloperidol phenotype recommendations
Published guidance from DPWG on how haloperidol should be dosed or substituted based on your CYP2D6 phenotype.
| Phenotype | What it means | Recommendation | Evidence |
|---|---|---|---|
| Ultrarapid MetabolizerCYP2D6 | Your body clears this drug faster, so the usual dose may not work as well. A higher dose or a different drug is often suggested. | DPWG Use 1.5 times the normal dose, or choose an alternative. Antipsychotics not metabolised (or metabolised to a much lesser extent) by CYP2D6 include flupentixol, penfluridol, quetiapine, olanzapine, or clozapine. |
Moderate |
| Normal MetabolizerCYP2D6 | Your CYP2D6 result is typical, so the usual dose is fine. | DPWG Use standard haloperidol dosing. |
Moderate |
| Intermediate MetabolizerCYP2D6 | Your body clears haloperidol slightly more slowly than average, but the effect is small and no dose change is needed. | DPWG No action is required. Use standard haloperidol dosing. |
Moderate |
| Poor MetabolizerCYP2D6 | Your body clears haloperidol slowly, which raises the concentration in your blood and increases side effect risk. A lower dose is typically recommended. | DPWG Use 60% of the normal dose. |
Moderate |
| IndeterminateCYP2D6 | We couldn't get a clear CYP2D6 result from your data, so we can't tailor advice for this drug. | DPWG Use standard haloperidol dosing and monitor response. |
Not rated |
| Not availableCYP2D6 | We do not have a CYP2D6 result for you, so we cannot personalize guidance for haloperidol. | DPWG Use standard haloperidol dosing and monitor response. |
Not rated |
Source: DPWG
The gene behind the guidance
CYP2D6 Cytochrome P450 2D6
CYP2D6 is the most clinically important pharmacogene. It metabolizes around a quarter of all prescription drugs, including many antidepressants, opioids, and stimulants. The gene is unusually variable: roughly 7 percent of people are poor metabolizers (they barely activate CYP2D6), and another 1 to 3 percent are ultrarapid metabolizers (their enzyme is overactive).
The v4 report preserves the activity score used in its interpretation. Some medicines use a combined CYP2D6/CYP2C19 recommendation. CYP2D6 inhibitors can change functional metabolism; a genotype alone does not capture that effect.
See all drugs affected by CYP2D6Browse the full drug class: Antipsychotics.
Related medications
Find out how your genetics affect Haldol
Informational only, not medical advice. Pharmacogenetic guidance describes population-level patterns; your individual response depends on many factors. Never start, stop, or change a medication without talking to your prescribing clinician.