No

Antipsychotic Agent, Benzisoxazole

Management of psychotic disorders (eg, schizophrenia)

C

Hypersensitivity to risperidone or any component of the formulation

Low to moderately sedating, use with caution in disorders where CNS depression is a feature. Use with caution in Parkinson's disease. Caution in patients with hemodynamic instability; bone marrow suppression; predisposition to seizures; subcortical brain damage; severe cardiac, hepatic, or respiratory disease. Use with caution in renal dysfunction. Esophageal dysmotility and aspiration have been associated with antipsychotic use - use with caution in patients at risk of aspiration pneumonia (ie, Alzheimer's disease). Caution in breast cancer or other prolactin-dependent tumors (may elevate prolactin levels). May alter temperature regulation or mask toxicity of other drugs due to antiemetic effects. May alter cardiac conduction (low risk relative to other neuroleptics) - life-threatening arrhythmias have occurred with therapeutic doses of neuroleptics. Avoid in patients with QT prolongation. Use with caution in elderly patients or in patients who would not tolerate transient hypotensive episodes (cerebrovascular or cardiovascular disease) due to potential for orthostasis.

May cause extrapyramidal reactions, including pseudoparkinsonism, acute dystonic reactions, akathisia, and tardive dyskinesia (risk of these reactions is low relative to other neuroleptics, and is dose-dependent). May be associated with neuroleptic malignant syndrome (NMS) or pigmentary retinopathy.

>10%: Central nervous system: Insomnia, agitation, anxiety, headache

1% to 10%:

Cardiovascular: Hypotension (especially orthostatic), tachycardia

Central nervous system: Sedation, dizziness, restlessness, anxiety, extrapyramidal reactions (dose dependent), dystonic reactions, pseudoparkinson, tardive dyskinesia, neuroleptic malignant syndrome, altered central temperature regulation

Dermatologic: Photosensitivity (rare), rash, dry skin

Endocrine & metabolic: Amenorrhea, galactorrhea, gynecomastia, sexual dysfunction

Gastrointestinal: Constipation, GI upset, xerostomia, dyspepsia, vomiting, abdominal pain, nausea, anorexia, weight gain

Genitourinary: Polyuria

Ocular: Abnormal vision

Respiratory: Rhinitis, coughing, sinusitis, pharyngitis, dyspnea

Incidence Unknown: Dysphagia, esophageal dysmotility

CYP2D6 enzyme substrate and weak inhibitor; CYP3A4 substrate

Risperidone may antagonize effects of levodopa; carbamazepine decreases risperidone serum concentrations; clozapine decreases clearance of risperidone

Risperidone is a benzisoxazole derivative, mixed serotonin-dopamine antagonist; binds to 5-HT₂-receptors in the CNS and in the periphery with a very high affinity; binds to dopamine-D₂ receptors with less affinity. The binding affinity to the dopamine-D₂ receptor is 20 times lower than the 5-HT₂ affinity. The addition of serotonin antagonism to dopamine antagonism (classic neuroleptic mechanism) is thought to improve negative symptoms of psychoses and reduce the incidence of extrapyramidal side effects. Alpha₁, alpha₂ adrenergic, and histaminergic receptors are also antagonized with high affinity. Risperidone has low to moderate affinity for 5HTIC, 5HTID, and 5HTIA receptors, weak affinity for D₁ and no affinity for muscarinics or beta₁ and beta₂ receptors

Absorption: Oral: Rapid

Metabolism: Extensive by cytochrome P-450

Protein binding: Plasma: 90%

Half-life: 24 hours (risperidone and its active metabolite)

Time to peak: Peak plasma concentrations within 1 hour

Recommended starting dose: 0.5-1 mg twice daily; slowly increase to the optimum range of 4-8 mg/day; daily dosages >10 mg does not appear to confer any additional benefit, and the incidence of extrapyramidal reactions is higher than with lower doses

Dosing adjustment in renal, hepatic impairment, and elderly: Starting dose of 0.25-0.5 mg twice daily is advisable

No information available to require special precautions

Up to 10% of dental patients will experience significant dry mouth and orthostatic hypotension. These effects disappear with cessation of drug therapy.

Use exactly as directed (do not increase dose or frequency); may cause physical and/or psychological dependence. It may take 2-3 weeks to achieve desired results; do not discontinue without consulting prescriber. Dilute solution with water, milk, orange or grapefruit juice; do not dilute with beverages containing caffeine, tannin, or pectinate (eg, coffee, colas, tea, or apple juice). Avoid excess alcohol or caffeine and other prescription or OTC medications not approved by prescriber. Maintain adequate hydration (2-3 L/day of fluids unless instructed to restrict fluid intake). You may experience excess sedation, drowsiness, restlessness, dizziness, or blurred vision (use caution driving or when engaging in tasks requiring alertness until response to drug is known); dry mouth, nausea, or GI upset (small frequent meals, frequent mouth care, chewing gum, or sucking lozenges may help); postural hypotension (use caution climbing stairs or when changing position from lying or sitting to standing); or urinary retention (void before taking medication). Report persistent CNS effects (eg, trembling fingers, altered gait or balance, excessive sedation, seizures, unusual muscle or skeletal movements, anxiety, abnormal thoughts, confusion, personality changes); chest pain, palpitations, rapid heartbeat, severe dizziness; swelling or pain in breasts (male and female), altered menstrual pattern, sexual dysfunction; pain or difficulty on urination; vision changes; skin rash or yellowing of skin; difficulty breathing; or worsening of condition. Pregnancy/breast-feeding precautions: Inform prescriber if you are or intend to be pregnant. Do not breast-feed.

Monitor and observe for extrapyramidal effects, orthostatic blood pressure changes for 3-5 days after starting or increasing dose

Solution, oral: 1 mg/mL (100 mL)

Tablet: 0.25 mg, 0.5 mg, 1 mg, 2 mg, 3 mg, 4 mg

Borison RL, Pathiraja AP, Diamond BI, et al, "Risperidone: Clinical Safety and Efficacy in Schizophrenia," Psychopharmacol Bull, 1992, 28(2):213-8.

Byerly MJ, Greer RA, and Evans DL "Behavioral Stimulation Associated With Risperidone Initiation," Am J Psychiatry, 1995, 152(7):1096-7.

Cardoni AA, "Risperidone: Review and Assessment of Its Role in the Treatment of Schizophrenia," Ann Pharmacother, 1995, 29(6):610-8.

Cohen LJ, "Risperidone," Pharmacotherapy, 1994, 14(3):253-65.

Dave M, "Two Cases of Risperidone-Induced Neuroleptic Malignant Syndrome," Am J Psychiatry, 1995, 152(8):1233-4.

Gelders YG, "Thymosthenic Agents, a Novel Approach in the Treatment of Schizophrenia," Br J Psychiatry Suppl, 1989, 5:33-6.

Goss JB, "Concomitant Use of Thioridazine With Risperidone," Am J Health Syst Pharm, 1995, 52(9):1012.

Meylan C, Bondolfi G, Aubert AC, et al, "Reversible Neutropenia During a Cold: Possible Involvement of Risperidone? A Case Report," Eur Neuropsychopharmacol, 1995, 5(1):1-2.

Singer S, Richards C, and Boland RJ, "Two Cases of Risperidone-Induced Neuroleptic Malignant Syndrome," Am J Psychiatry, 1995, 152(8):1234.

Swanson CL Jr, Price WA, and McEvoy JP, "Effects of Concomitant Risperidone and Lithium Treatment," Am J Psychiatry, 1995, 152(7):1096.

Tekell JL, Smith EA, and Silva JA, "Prolonged Erection Associated With Risperidone Treatment," Am J Psychiatry, 1995, 152(7):1097.