RESPAL 2MG 20CAP

Indications

Approved Uses

Schizophrenia; Bipolar I disorder-acute manic or mixed episodes (monotherapy or adjunct to lithium/valproate); Irritability associated with autistic disorder (children/adolescents).

Off-Label Uses

Common off-label uses include Tourette syndrome/tic disorders, augmentation in treatment-resistant depression, and behavioral symptoms/agitation in dementia (not recommended routinely due to boxed warning and increased mortality risk); other uses (e.g., OCD augmentation, delirium) may be considered case-by-case.

Dosage & Administration

Dosing by Condition

Schizophrenia (adults): start ~2 mg/day (once daily or divided), titrate to usual target 4-6 mg/day (some patients 4-8 mg/day); avoid routine doses >8 mg/day due to higher EPS risk. Bipolar I acute mania/mixed (adults): start 2-3 mg/day, adjust by ~1 mg/day; usual range 1-6 mg/day. Autism-related irritability (pediatrics): weight-based low starting dose (e.g., 0.25 mg/day if <20 kg; 0.5 mg/day if ≥20 kg) with gradual titration; typical effective range ~0.5-3 mg/day.

Initial Dose

2mg once daily or in two divided doses for schizophrenia

Maintenance Dose

4-8mg/day for schizophrenia; 1-6mg/day for bipolar mania

Maximum Dose

16mg/day (schizophrenia); 6mg/day (bipolar mania)

Children's Dosage

Autism-related irritability (5-17 years): 0.25mg/day for <20kg, 0.5mg/day for ≥20kg; titrate after ≥4 days; max 3mg/day. Schizophrenia (13-17 years): 0.5mg/day initial, target 3mg/day, max 6mg/day. Bipolar mania (10-17 years): 0.5mg/day initial, target 2.5mg/day, max 6mg/day

Dose Adjustment Notes

Elderly and patients with renal or hepatic impairment: use lower starting doses and slower titration (commonly 0.5 mg twice daily initially, then increase cautiously). Strong CYP2D6 inhibitors (e.g., fluoxetine/paroxetine) can increase exposure-consider dose reduction; strong enzyme inducers (e.g., carbamazepine) can decrease exposure-may require dose increase with monitoring.

Side Effects

Common Side Effects

Somnolence/sedation, dizziness, extrapyramidal symptoms (parkinsonism, akathisia, dystonia, tremor), weight gain/increased appetite, hyperprolactinemia, gastrointestinal effects (nausea, constipation, dry mouth), fatigue; orthostatic hypotension can occur.

Safety & Warnings

Contraindications

Contraindication: known hypersensitivity to risperidone (and typically to paliperidone, its active metabolite) or excipients; dementia-related psychosis is not a contraindication but a boxed warning/not approved indication.

Warnings & Precautions

Warnings/precautions include: increased mortality in elderly with dementia-related psychosis and increased cerebrovascular event risk in that population; monitor for NMS and tardive dyskinesia; metabolic monitoring (weight, glucose, lipids); orthostatic hypotension and cardiovascular/QT-risk caution; seizure risk; hyperprolactinemia; caution in renal/hepatic impairment and in Parkinsonism/dementia with Lewy bodies.

Age Restriction

Not approved under 5 years; pediatric use is indication-specific (e.g., irritability associated with autistic disorder ages 5-16 years; schizophrenia ages 13-17; bipolar mania ages 10-17).

Driving Warning

May Cause Drowsiness

Drug Interactions

Drug Interactions

Key interactions: CNS depressants (additive sedation), antihypertensives (additive hypotension), CYP2D6 inhibitors (e.g., fluoxetine/paroxetine ↑ risperidone exposure), CYP3A4 inducers (e.g., carbamazepine/rifampin ↓ exposure), dopamine agonists/levodopa (pharmacodynamic antagonism), and caution with QT-prolonging drugs (additive QT risk).

Interaction Severity

MAJOR/clinically significant: strong CYP2D6 inhibitors (fluoxetine, paroxetine) ↑ risperidone exposure; strong enzyme inducers (carbamazepine, phenytoin, rifampin) ↓ exposure; additive QT-risk with other QT-prolonging drugs in at-risk patients; additive CNS depression/psychomotor impairment with alcohol/benzodiazepines/opioids. MODERATE: antihypertensives (additive hypotension); dopamine agonists/levodopa (pharmacodynamic antagonism).

Food Interaction

No restriction

Special Populations

Pregnancy

Category C

Children

Autism-related irritability (5-17 years): 0.25mg/day for <20kg, 0.5mg/day for ≥20kg; titrate after ≥4 days; max 3mg/day. Schizophrenia (13-17 years): 0.5mg/day initial, target 3mg/day, max 6mg/day. Bipolar mania (10-17 years): 0.5mg/day initial, target 2.5mg/day, max 6mg/day

Elderly

Start at 0.5mg twice daily; increase by 0.5mg twice daily increments; target 1-2mg twice daily. Monitor for orthostatic hypotension, sedation, and extrapyramidal symptoms. Avoid use in dementia-related psychosis.

Liver Impairment

Hepatic impairment: start 0.5 mg twice daily and titrate slowly/cautiously (applies to moderate-severe impairment; use caution).

Storage & Patient Advice

Patient Counseling

Take exactly as prescribed; do not stop abruptly without medical advice. Drowsiness/dizziness may occur-avoid driving until effects are known and avoid alcohol. Rise slowly to reduce orthostatic dizziness. Report abnormal involuntary movements, severe stiffness, fever/confusion (possible NMS), or symptoms of high blood sugar/rapid weight gain. Keep follow-up appointments for weight and metabolic monitoring; discuss pregnancy/breastfeeding plans with the prescriber.

Monitoring Requirements

Baseline and periodic: weight/BMI (± waist circumference), blood pressure (including orthostatic if symptomatic), fasting glucose or HbA1c, lipid profile; assess EPS/tardive dyskinesia and clinical response; consider prolactin if symptomatic; consider ECG in patients with cardiac disease, electrolyte abnormalities, or concomitant QT-prolonging drugs.

Pharmacology

Mechanism of Action

Antagonism of dopamine D2 and serotonin 5‑HT2A receptors; also blocks α1-adrenergic and H1 receptors (and other serotonergic/adrenergic sites), contributing to efficacy and adverse effects.

Duration of Effect

Clinical effect per dose is typically about 24 hours (supports once-daily dosing in many patients; some may require twice-daily dosing depending on response/tolerability).

Half-Life

Risperidone t½: ~3 hours in extensive metabolizers and ~20 hours in poor CYP2D6 metabolizers; 9-hydroxyrisperidone t½: ~21 hours; active moiety (risperidone + 9-hydroxyrisperidone) effective t½ is ~20-24 hours.

Bioavailability

Approximately 70% oral bioavailability.

Metabolism

Hepatic metabolism primarily via CYP2D6 to the active metabolite 9-hydroxyrisperidone (paliperidone), with minor contribution from CYP3A4.

Protein Binding

Risperidone ~88-90% protein bound; 9-hydroxyrisperidone ~77% protein bound.

Product Information

Available Dosage Forms

For RESPAL 2 mg (SFDA 1003257033): Oral tablet (blister pack). For risperidone generally: tablets, orally disintegrating tablets, oral solution, and long-acting injectable formulations exist in some markets.

Composition per Dose

Each tablet: 2mg risperidone

OTC Alternatives

No OTC alternative

Psych Class

Antipsychotic-Atypical

Controlled Substance

No

Reviewed by Al Mujtama Pharmacy Medical Review Team. Last reviewed 17-06-2026