Is Risperdal affected by genetics?
Yes. Its active ingredient has published pharmacogenetic guidance for a gene that varies between people.
Risperdal is affected by pharmacogenetics through the CYP2D6 gene. Your genotype for this gene can change how well Risperdal 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 Risperdal
Risperidone Affected by CYP2D6
Affected by CYP2D6. Guidance from DPWG, moderate evidence.
Read the full risperidone genetics guideRisperidone phenotype recommendations
Published guidance from DPWG on how risperidone should be dosed or substituted based on your CYP2D6 phenotype.
| Phenotype | What it means | Recommendation | Evidence |
|---|---|---|---|
| Ultrarapid MetabolizerCYP2D6 | Your body turns risperidone into its active form faster than usual, and it is more likely not to work well for you. Your doctor may choose a different drug or adjust the dose carefully. | DPWG Choose an alternative or titrate the dose according to the maximum dose for the active metabolite (paliperidone) (oral 12 mg/day for adults and children from 15 years of age weighing at least 51 kg and 6 mg/day for children from 15 years of age weighing less than 51 kg; intramuscular 75 mg per 2 weeks). |
Moderate |
| Normal MetabolizerCYP2D6 | Your CYP2D6 result is typical, so the usual dose is fine. | DPWG Use standard risperidone dosing. |
Moderate |
| Intermediate MetabolizerCYP2D6 | Your body clears risperidone slightly more slowly than average, but the effect is small and no dose change is needed. | DPWG No action is required. Use standard risperidone dosing. |
Moderate |
| Poor MetabolizerCYP2D6 | Your body clears risperidone slowly, so more of it builds up and side effects are more likely. About two-thirds of the usual dose is advised, and less if side effects still occur. | DPWG Use 67% of the normal dose. If problematic side effects originating in the central nervous system occur despite this reduced dose, then reduce the dose further to 50% 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 risperidone dosing and monitor response. |
Not rated |
| Not availableCYP2D6 | We do not have a CYP2D6 result for you, so we cannot personalize guidance for risperidone. | DPWG Use standard risperidone 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 Risperdal
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.