Residon

Residon

risperidone

Manufacturer:

Pharmathen

Distributor:

JF Draf
Full Prescribing Info
Contents
Risperidone.
Description
Each tablet contains: 2 mg and 4 mg of Risperidone.
Action
Pharmacology: Pharmacodynamics: Drugs known to prolong the QT interval: As with other antipsychotics, caution is advised when prescribing risperidone with medicinal products known to prolong the QT interval, such as antiarrhythmics (e.g., quinidine, dysopiramide, procainamide, propafenone, amiodarone, sotalol), tricyclic antidepressants (i.e., amitriptyline), tetracyclic antidepressants (i.e., maprotiline), some antihistamines, other antipsychotics, some antimalarials (i.e., quinine and mefloquine), and with medicines causing electrolyte imbalance (hypokalemia, hypomagnesiaemia), bradycardia, or those which inhibit the hepatic metabolism of risperidone. This list is indicative and not exhaustive.
Centrally-Acting Drugs and Alcohol: Risperidone should be used with caution in combination with other centrally-acting substances notably including alcohol, opiates, antihistamines and benzodiazepines due to the increased risk of sedation.
Levodopa and Dopamine Agonists: Risperidone may antagonise the effect of levodopa and other dopamine agonists. If this combination is deemed necessary, particularly in end-stage Parkinson's disease, the lowest effective dose of each treatment should be prescribed.
Drugs with Hypotensive Effect: Clinically significant hypotension has been observed postmarketing with concomitant use of risperidone and antihypertensive treatment.
Paliperidone: Concomitant use of oral Risperidone Tablets with paliperidone is not recommended as paliperidone is the active metabolite of risperidone and the combination of the two may lead to additive active antipsychotic fraction exposure.
Pharmacokinetics: Food does not affect the absorption of Risperidone Tablets. Risperidone is mainly metabolized through CYP2D6, and to a lesser extent through CYP3A4. Both risperidone and its active metabolite 9-hydroxyrisperidone are substrates of P-glycoprotein (P-gp). Substances that modify CYP2D6 activity, or substances strongly inhibiting or inducing CYP3A4 and/or P-gp activity, may influence the pharmacokinetics of the risperidone active antipsychotic fraction.
Highly Protein-bound Drugs: When Risperidone is taken together with highly protein-bound drugs, there is no clinically relevant displacement of either drug from the plasma proteins.
When using concomitant medication, the corresponding label should be consulted for information on the route of metabolism and the possible need to adjust dosage.
Paediatric Population: Interaction studies have only been performed in adults. The relevance of the results from these studies in paediatric patients is unknown. The combined use of psychostimulants (e.g., methylphenidate) with Risperidone in children and adolescents did not alter the pharmacokinetics and efficacy of Risperidone.
Antibacterials: Erythromycin, a moderate CYP3A4 inhibitor and P-gp inhibitor, does not change the pharmacokinetics of risperidone and the active antipsychotic fraction.
Antipsychotic Fraction: Anticholinesterases: Donepezil and galantamine, both CYP2D6 and CYP3A4 substrates, do not show a clinically relevant effect on the pharmacokinetics of risperidone and the active antipsychotic fraction.
Antiepileptics: Carbamazepine, a strong CYP3A4 inducer and a P-gp inducer, has been shown to decrease the plasma concentrations of the active antipsychotic fraction of risperidone. Similar effects may be observed with e.g., phenytoin and phenobarbital which also indue CYP3A4 hepatic enzyme, as well as P-glycoprotein.
Topiramate modestly reduced the bioavailability of risperidone, but not that of the active antipsychotic fraction. Therefore, this interaction is unlikely to be of clinical significance.
Antifungals: Itraconazole, a strong CYP3A4 inhibitor and a P-gp inhibitor, at a dosage of 200 mg/day increased the plasma concentrations of the active antipsychotic fraction by about 70%, at risperidone doses of 2 to 8 mg/day.
Ketoconazole, a strong CYP3A4 inhibitor and a P-gp inhibitor, at a dosage of 200 mg/day increased the plasma concentrations of risperidone and decreased the plasma concentrations of 9-hydroxyrisperidone.
Antipsychotics: Phenothiazines may increase the plasma concentrations of risperidone but not those of the active antipsychotic fraction.
Antivirals: Protease inhibitors: No formal study data are available; however, since ritonavir is a strong CYP3A4 inhibitor and a weak CYP2D6 inhibitor, ritonavir and ritonavir-boosted protease inhibitors potentialy raise concentrations of the risperidone active antipsychotic fraction.
Beta blockers: Some beta-blockers may increase the plasma concentrations of risperidone but not those of the active antipsychotic fraction.
Calcium channel blockers: Verapamil, a moderate inhibitor of CYP3A4 and an inhibitor of P-gp, increases the plasma concentration of risperidone and the active antipsychotic fraction.
Gastrointestinal drugs: H-receptor antagonist: Cimetidine and ranitidine, both weak inhibitors of CYP2D6 and CYP3A4, increased the bioavailability of risperidone, but only marginally that of the active antipsychotic fraction.
SSRIs and Tricyclic antidepressants: Fluoxetine, a strong CYP2D6 inhibitor, increases the plasma concentration of risperidone, but less so of the active antipsychotic fraction.
Paroxetine, a strong CYPD6, increases the plasma concentrations of risperidone, but at dosages up to 20 mg/day, less so of the active antipsychotic fraction. However, higher doses of paroxetine may elevate concentrations of the risperidone active antipsychotic fraction.
Tricyclic antidepressants may increase the plasma concentrations of risperidone but not those of the active antipsychotic fraction. Amitriptyline does not affect the pharmacokinetics of risperidone or the active antipsychotic fraction.
Sertraline, a weak inhibitor of CYP2D6, and fluvoxamine, a weak inhibitor of CYP3A4, at dosages up to 100 mg/day are not associated with clinically significant changes in concentrations of the risperidone active antipsychotic fraction.
However, doses higher than 100 mg/day of sertraline or fluvoxamine may elevate concentrations of the risperidone active antipsychotic fraction.
Indications/Uses
Risperidone is indicated in the treatment of patient groups with schizoprenia, including the first psychotic episode, acute schizophrenic episodes, chronic schizophrenia and other psychotic conditions where positive symptoms (such as hallucinations, delirium ideas, thought disorders, hostility, distrust) and/or negative symptoms (such as emotional bluntness, emotional and social withdrawal, speech difficulty) are instense. Risperidone also alleviates emotional disorders (such as depression, feeling of guilt, anxiety) that relate to schizophrenia.
Risperidone is also effective in maintaining clinical improvement during continuous treatment in patients who have showed response to the initial treatment.
Additionally, risperidone is indicated in the treatment of behavioral disorders in patients with dementia whose symptoms such as aggressiveness (verbal outbreaks-outbursts, physical violence) activity disorders (stimulation, agitation) or psychotic syndromes are intense.
Risperidone is also indicated as additional treatment in with mood stabilizers in the treatment of maniac episodes accompanied by bipolar disorders. These episodes are characterized by symptoms increased, extensive or irritable mood, excessive self-esteem, reduced need for sleep, suppressed speech, origin thoughts and difficulty in concentration or poor judgment including disruptive or aggressive behavior.
Risperidone is indicated in the treatment of developmental or other disorders of disruptive behavior in patients with mental function that is rated under the average or mental retirement, whose destructive behavior (i.e. aggressiveness, impulsiveness, self-injuring behaviors) is intense.
Dosage/Direction for Use
Risperidone may be given in 1 or 2 divided doses daily. The usual initial daily dose of risperidone is 2 mg; this may be increased to 4 mg daily on the second day, and subsequently adjusted further as required in increments or decrements of 1 or 2 mg daily, generally at intervals of not less than one week.
Most patients benefit from doses of 4 to 6 mg daily.
Extrapyramidal symptoms may be more likely with doses above 10 mg daily; daily doses above 8 mg if divided into 2 doses is not recommended, although higher doses are permitted if given as a single dose. The maximum recommended dose is 16 mg daily.
An initial dose of 0.5 mg twice daily slowly increased in steps of 0.5 mg twice daily if necessary to a dose of 1 to 2 mg twice daily is recommended for the elderly and for patients with renal or hepatic impairment.
Overdosage
One or more of the following symptoms may occur: reduced consciousness, indolence, somnolence, extensive tremors or extensive muscular rigidity. At the same time, the patient can start treatment of these discomforts by taking active charcoal, which absorbs the amount of medicine that has remained in the stomach.
If the patient has lost his/her senses, make sure to keep his/her respiratory routes open and ensure oxygenation.
Contraindications
Risperidone should not be taken in case of hypersensitivity to risperidone or any of its excipients.
Special Precautions
General: During long-term, risperidone may cause involuntary facial movements. In such a case, immediately consult the doctor.
Very rarely, confusion conditions may appear, as well as decreased level of consciousness, high fever or muscular rigidity.
Body weight increase: Try to consume moderate amounts of food since risperidone may increase the body weight.
Cardiovascular diseases, disturbed renal or hepatic function, Parkinson, epilepsy. If the patient suffers from any of the aforementioned disease, notify the doctor.
Use in Children: Not recommended for children aged under 15.
Use in Elderly: Elderly patients should receive a smaller amount of risperidone than the one an adult would normally use.
Use In Pregnancy & Lactation
It is advisable to avoid the use of risperidone during pregnancy.
The use of risperidone during breast feeding is not recommended.
Adverse Reactions
Risperidone may increase alcohol's action, as well as the action of medicines that reduce the ability to react (i.e., tranquilizers, narcotic analgesics, several antihistaminics and several antidepressants) and several antihypertensives.
Therefore, the patient must not consume alcoholic beverages.
Some medicines that are used in the treatment of Parkinson's disease (dopamine agonists i.e., levodopa) may agonize risperidone action.
Carbamazepine, a medicine used mainly in epilepsy or trigeminal neuralgia (strong facial pain) may affect risperidone effectiveness.
Most common: somnolence, stimulation, anxiety and headache.
Less common: indolence, difficulty in concentration, fatigue, blurred vision, dizziness, dyspepsia, nausea, vomit, epigastric pain, difficulty in bowel movement, sexual ability disorders, minimum urine incontinence, nasal blockage, skin rash.
Suppression, usually moderate and of small duration may occur more often in children than adults.
A small increase in body weight may be noted during treatment and small kinetic disorders such as tremor, light rigidity of the muscles and agitation may appear.
In some cases, sudden weakness and numbness on the face, arms or legs has been noted, especially on one side or even moments of bad speech articulation.
During long treatment, involuntary movements of the tongue, face or jaws may be noted.
After long treatment. some people may present breast increase, galactorrhea or menstrual disorder.
Drug Interactions
Risperidone may increase alcohol's action, as well as the action of medicines that reduce the ability to react (i.e., tranquilizers, narcotic analgesics, several antihistaminics and several antidepressants) and several antiypertensives.
Therefore, the patient must not consume alcoholic beverages.
Some medicines that are used in the treatment of Parkinson's disease (dopamine agonists i.e., levodopa) may agonize risperidone action.
Carbamazepine, a medicine used mainly in epilepsy or trigeminal neuralgia (strong facial pain) may affect risperidone effectiveness.
Storage
Store at temperatures not exceeding 25°C. Protect from light.
MIMS Class
ATC Classification
N05AX08 - risperidone ; Belongs to the class of other antipsychotics.
Presentation/Packing
FC tab 2 mg (yellow round biconvex, with dimensions 8.1 +/- 0.1 mm in diameter and thickness 4.2 +/- 0.2 mm) x 50's. 4 mg (green round biconvex, scored on one side with dimensions 8.1 +/- 0.1 mm in diameter and thickness 4.2 +/- 0.2 mm) x 50's.
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