Each 1ml oral solution contains 1mg Risperidone.
Tablet: starch, cellulose, aerosil, magnesium stearate.
Oral solution: sorbitol, flavor, preservatives, purified water.
MECHANISM OF ACTION:
Respond is a novel antipsychotic belonging to a new class of antipsychotic agents, the benzisoxazole derivatives. Respond is a selective monoaminergic antagonist with a high affinity for both serotonergic 5-HT2 and dopaminergic D2 receptors. Respond binds also to 1- adrenergic receptors and, with lower affinity, to H1- histaminergic and 2-adrenergic receptors. Respond has no affinity for cholinergic receptors. Although Respond is a potent D2 antagonist, that is considered to improve the positive symptoms of schizophrenia, it causes less depression of motor activity and induction of catalepsy than classical neuroleptics. Balanced central serotonin and dopamine antagonism may reduce the tendency to cause extrapyramidal side effects, and extend the therapeutic activity to the negative and affective symptoms of schizophrenia.
Respond is indicated for the treatment of acute and chronic schizophrenic psychoses and other psychotic conditions, in which positive symptoms (such as hallucinations, delusions, thought disturbances, hostility, suspiciousness), and/or negative symptoms (such as blunted affect, emotional and social withdrawal, poverty of speech) are prominent. Respond also alleviates affective symptoms (such as depression, guilt feelings, anxiety) associated with schizophrenia.
Food does not affect the absorption of Respond.
Switching from other anti psychotic: where medically appropriate, gradual discontinuation of the previous treatment while Respond therapy is initiated is recommended. Where medically appropriate when switching patients from depot antipsychotics, consider initiating Respond therapy in place of the next scheduled injection. The need for continuing existing antiparkinson medication should be re-evaluated periodically.
Children: Use of Respond for schizophrenia in children aged less than 15 years has not been formally evaluated.
Adults: Respond may be given once or twice daily. All patients, whether acute or chronic, should start with 2mg/day of Respond. The dosage may be increased to 4mg/day on the second day. Some patients, such as first episode patients, may benefit from a slower rate of titration. Most patients will benefit from daily dose between 4 and 6mg/day although in some, an optimal response may be obtained at lower doses.
Doses above 10mg/day generally have not been shown to provide additional efficacy to lower doses and may increase the risk of extrapyramidal symptoms.
Doses above 10mg/day should only be used in individual patients if the benefit is considered to outweigh the risk.
Elderly: A starting dose of 0.5mg twice daily is recommended. This dosage can be individually adjusted with 0.5mg twice daily increments to 1-2mg twice daily.
Renal and liver disease: A starting dose of 0.5mg twice daily is recommended. This dosage can be individually adjusted with 0.5mg by twice daily increments to 1-2mg twice daily. Respond should be used with caution in this group of patients until further experience is gained.
Respond is generally well tolerated and in many instances it has been difficult to differentiate adverse events from symptoms of the underlying disease.
Common: Insomnia, agitation, anxiety, headache.
Less common: Somnolence, fatigue, dizziness, impaired concentration, constipation, dyspepsia, nausea/vomiting, abdominal pain, blurred vision, erectile dysfunction, urinary incontinence, rhinitis, rash and other allergic reactions.
Orthostatic dizziness, hypotension including orthostatic, tachycardia including reflex tachycardia and hypertension.
Weight gain, oedema and increased hepatic enzyme levels have been observed during treatment with risperidone.
Rarely: A decrease in neutrophil and/or thrombocyte count has been reported, water intoxication with hyponatraemia, body temperature dysregulation and seizures.
Respond can induce a dose dependent increase in plasma prolactin concentration, disturbances of the menstrual cycle and amenorrhea.
The incidence and severity of extrapyramidal symptoms are significantly less than with haloperidol, and they are reversible upon dose reduction and/or administration of antiparkinson medication, if necessary.
It is contraindicated in patients with a known hypersensitivity to risperidone or any of other ingredients in the product.
It may antagonize the effect of levodopa and other dopamine agonists.
Carbamazepine has been shown to decrease the plasma levels of antipsychotic fraction of the drug. A similar effect might be anticipated with other drugs which stimulate metabolizing enzymes in the liver. On initiation of carbamazepine or other hepatic enzyme-inducing drugs, the dosage of Respond should be re-evaluated and increased if necessary. Conversely, on discontinuation of such drugs, the dosage of the drug should be re-evaluated and decreased if necessary.
Phenothiazines, tricyclic antidepressants and some beta-blockers may increase the plasma concentrations of risperidone.
• Due to -blocking activity of Respond, orthostatic hypotension can occur, especially during the initial dose titration period. A dose reduction should be considered if hypotension occurs.
• It should be used with caution in patients with known cardiovascular disease.
• If further sedation is required, an additional drug (such as benzodiazepine) should be administered rather than increasing the dose of the drug.
• If signs and symptoms of tardive dyskinesia appear, the discontinuation of all antipsychotic drugs should be considered.
• It is recommended to halve both the starting dose and the subsequent dose increments in geriatric patients and in the patients with renal or liver insufficiency.
• Caution should also be exercised when prescribing the drug to patients with Parkinson's disease since theoretically, it may cause a deterioration of the disease.
• Classical neuroleptics are known to lower the seizure threshold. Caution is recommended when treating patients with epilepsy.
• As with other antipsychotic, patients should be advised of the potential for weight gain.
EFFECTS ON ABILITY TO DRIVE AND USE MACHINES:
It may interfere with activities requiring mental alertness. Therefore, patients should be advised not to drive or operate machinery until their individual susceptibility is known.
USE IN PREGNANCY OR LACTATION:
The safety of the drug for use during human pregnancy has not been established. Therefore, it should only be used during pregnancy if the benefits outweigh the risks.
The drug is excreted in human milk. Therefore, woman receiving it should not breast feed.
Risperidone is completely absorbed after oral administration, reaching peak plasma concentration within 1-2 hours.
It has an active metabolite, which has a similar pharmacological activity to risperidone.
Elimination half life is 24 hours.
It was showed a slower elimination of risperidone in elderly and in patients with renal insufficiency. Risperidone plasma concentrations were normal in patients with liver insufficiency.