risperidone microspheres
Brands: RISPERDAL CONSTA
Last reviewed 2025-12-30
Reviewed by PsychMed Editorial Team.
Quick answers
What is risperidone microspheres?
Risperidone microspheres (Risperdal Consta) is a long-acting injectable formulation dosed every 2 weeks. It is used for schizophrenia maintenance and bipolar I maintenance (monotherapy or adjunct, per labeling), often when relapse risk is driven by inconsistent daily dosing.
What is RISPERDAL CONSTA?
RISPERDAL CONSTA is a brand name for risperidone microspheres.
What is RISPERDAL CONSTA (risperidone microspheres) used for?
Label indications include: Schizophrenia; maintenance treatment of bipolar I disorder.
What drug class is RISPERDAL CONSTA (risperidone microspheres)?
Long-acting injectable antipsychotic.
What is the mechanism of action of RISPERDAL CONSTA (risperidone microspheres)?
Long-acting injectable risperidone formulation (microspheres) providing sustained dopamine D2 and serotonin 5-HT2A antagonism; used for maintenance treatment when adherence support is prioritized.
What strengths does RISPERDAL CONSTA (risperidone microspheres) come in?
Intramuscular injection every 2 weeks (q2wk).
Is RISPERDAL CONSTA (risperidone microspheres) a controlled substance?
No — it is not scheduled as a controlled substance under U.S. federal law.
How is risperidone microspheres started as a long-acting injectable (LAI)?
Initiation includes an oral overlap period (often ~3 weeks) because the microsphere formulation has a delayed onset of sustained release. Missed-dose management similarly depends on timing and may require oral supplementation.
Snapshot
- Class: Long-acting injectable antipsychotic
- Common US brands: RISPERDAL CONSTA
- Long-acting injectable formulation available.
- Therapeutic drug monitoring not routinely recommended.
- Last reviewed: 2025-12-30
Clinical Highlights
Risperidone microspheres (Risperdal Consta) is a long-acting injectable formulation dosed every 2 weeks. It is used for schizophrenia maintenance and bipolar I maintenance (monotherapy or adjunct, per labeling), often when relapse risk is driven by inconsistent daily dosing. A key practical difference versus many newer depots is the initial release lag: label initiation includes a ~3-week oral risperidone (or other antipsychotic) overlap to maintain coverage while the depot begins therapeutic release.
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- Pharmacology mirrors risperidone/paliperidone-class D2/5-HT2A blockade: prolactin elevation and EPS are common clinical constraints, and metabolic monitoring remains important.
- The compare view provides a depot-focused risk snapshot; the evidence feed can help track newer effectiveness and safety studies.
- Schizophrenia (adults): long-acting maintenance formulation.
- Bipolar I disorder: maintenance treatment (monotherapy or adjunct).
Dosing & Formulations
Administration is intramuscular every 2 weeks. Typical maintenance dosing starts at 25 mg q2wk, with higher doses used when needed and tolerated per labeling. Initiation includes an oral overlap period (often ~3 weeks) because the microsphere formulation has a delayed onset of sustained release. Missed-dose management similarly depends on timing and may require oral supplementation.
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- Product handling and administration are more workflow-intensive than some depots (reconstitution steps, site selection, and documentation). Standardized checklists reduce dosing errors.
Monitoring & Risks
Boxed warning: increased mortality in elderly patients with dementia-related psychosis (antipsychotic class warning). Prolactin elevation is common and can present as sexual dysfunction, menstrual changes, galactorrhea, or bone health concerns; monitoring is typically symptom-driven.
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- EPS and akathisia can occur, particularly at higher doses or when combined with other dopamine-blocking agents; routine movement-disorder screening is part of follow-up.
- Metabolic monitoring remains standard (weight/BMI, lipids, glucose), as weight gain and cardiometabolic change can still occur.
- Injection-site reactions and sedation/orthostasis can occur; rotation of sites and falls-risk assessment are common in older adults or medically complex patients.
Drug Interactions
Risperidone is metabolized by CYP2D6. Strong 2D6 inhibitors (some SSRIs) can raise risperidone exposure and adverse effects; review interaction profiles when adding antidepressants. Enzyme inducers can reduce exposure and increase relapse risk; depot dose adjustments are less “steerable” than with daily oral dosing.
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- Additive CNS depression and orthostasis can occur with sedatives, alcohol, or antihypertensives; clinical monitoring is individualized to baseline risk.
Practice Notes
The “overlap + lag” period is the key failure mode; initiation checklists that specify overlap duration and follow-up timing reduce early relapse risk. Because drug release continues after discontinuation, clinical effects can persist for weeks; side-effect plans often prioritize early detection rather than waiting for rapid washout.
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- Use the print handout for clinic workflows and the bipolar disorder hub when coordinating mood-stabilizer combinations.
Long-acting injectable (LAI) options
- Interval
- q2wk
- Oral overlap
- Yes — ~3 weeks due to lag
- Injection site
- Deltoid or gluteal
- Notes
- 3‑week lag to therapeutic release; continue oral overlap
References
- RISPERDAL CONSTA prescribing information (DailyMed, 2025). — DailyMed (2025)
- Long Acting Injectable Risperidone: Efficacy AND Safety OF THE First Long Acting Atypical Antipsychotic — American Journal of Psychiatry (2003)
- The CANMAT and ISBD Guidelines for the Management of Patients With Bipolar Disorder: 2021 Update — Bipolar Disorders (2021)Guidelinebipolarclinical
- AGNP Consensus Guidelines for Therapeutic Drug Monitoring in Neuropsychopharmacology — Pharmacopsychiatry (2018)
