Description of the active substance:
This information is a reference and it is not enough that the drug has been prescribed by a doctor ..
PHARMACHOLOGIC EFFECT
An antipsychotic agent (neuroleptic), a benzisoxazole derivative. Has a high affinity for serotonin 5-HT 2 - and dopamine D 2 -receptors. Associated with? 1 -adrenoceptors and, with a slightly lower affinity, with histamine H 1 -receptors and? 2- adrenoreceptors. Has no affinity for cholinergic receptors. Although risperidone is a potent D 2 antagonist (which is believed to be the main mechanism for improving the productive symptoms of schizophrenia), it causes less pronounced inhibition of motor activity and to a lesser degree induces catalepsy than classical antipsychotics. Due to a balanced antagonism to serotonin and dopamine receptors in the central nervous system, the likelihood of developing extrapyramidal side effects decreases.
Risperidone can induce a dose-dependent increase in prolactin concentration in the blood plasma.
PHARMACOKINETICS
After intake of risperidone completely absorbed from the gastrointestinal tract, C max in the plasma is achieved within 1-2 hours. Food has no effect on the absorption of risperidone.
C ss risperidone in the body in most patients is achieved within 1 day. C ss 9-hydroxyrisperidone is reached within 4-5 days. The concentration of risperidone in plasma is proportional to the dose (in the range of therapeutic doses).
Risperidone is rapidly distributed in the body, V d is 1-2 l / kg. In plasma, risperidone binds to albumin and alpha 1 glycoprotein. The binding of risperidone to plasma proteins is 88%, 9-hydroxyrisperidone - by 77%.
Risperidone is metabolized in the liver with the participation of the CYP2D6 isoenzyme with the formation of 9-hydroxyrisperidone, which has a similar pharmacological effect to risperidone. The antipsychotic effect is due to the pharmacological activity of risperidone and 9-hydroxyrisperidone. Another way of metabolizing risperidone is N-dealkylation.
After ingestion in patients with psychosis T 1/2 risperidone from the plasma is 3 h. T 1/2 9-hydroxyrisperidone and the active antipsychotic fraction is 24 h.
After 1 week of admission, 70% is excreted in the urine, 14% - with feces. In urine, the total content of risperidone and 9-hydroxyrisperidone is 35-45%. The remaining amount falls on inactive metabolites.
In elderly patients and in patients with renal insufficiency, after a single oral intake, increased plasma concentrations and delayed clearance of risperidone were observed.
INDICATIONS
Treatment of schizophrenia (including the first acute acute psychosis, acute attack of schizophrenia, chronic schizophrenia); psychotic states with pronounced productive (hallucinations, delusions, thinking disorders, hostility, suspicion) and / or negative (dull affect, emotional and social detachment, speech scarcity) symptomatology; to reduce affective symptoms (depression, guilt, anxiety) in patients with schizophrenia; prevention of recurrences (acute psychotic conditions) in the chronic course of schizophrenia; treatment of behavioral disorders in patients with dementia with symptoms of aggression (outbursts of anger, physical abuse), mental disorders (agitation, delirium) or psychotic symptoms; treatment of mania in bipolar disorders (as a mood stabilizer as a means of supporting therapy).
DOSING MODE
Individual. When administered orally, the initial dose for adults is 0.25-2 mg / day, on the second day - 4 mg / day. Then the dose can either be kept at the same level, or, if necessary, corrected. Usually the optimal therapeutic dose, depending on the indications, is in the range of 0.5-6 mg / day. In some cases, a slower dose increase and lower initial and maintenance doses may be justified.
In schizophrenia for elderly patients, as well as with concomitant diseases of the liver and kidneys, an initial dose of 500 Ојg 2 times / day is recommended. If necessary, the dose can be increased to 1-2 mg 2 times / day.
Maximum dose: when risperidone is administered at a dose of more than 10 mg / day, there is no increase in efficacy compared with lower doses, but the risk of developing extrapyramidal symptoms increases. The safety of the use of risperidone in doses greater than 16 mg / day has not been studied, therefore further excess of the dose is not allowed.
SIDE EFFECT
From the side of the central nervous system: often - insomnia, agitation, anxiety, headache; Possible - drowsiness, fatigue, dizziness, impaired ability to concentrate, violating the clarity of vision; rarely - extrapyramidal symptoms, (including tremor, rigidity, hypersalivation, bradykinesia, akathisia, acute dystonia). In patients with schizophrenia, tardive dyskinesia, NSA, thermoregulatory disorders and convulsive seizures are possible.
On the part of the digestive system: constipation, dyspeptic phenomena, nausea, vomiting, abdominal pain, increased activity of hepatic enzymes.
On the part of the reproductive system: priapism, erectile dysfunction, ejaculation, violation of orgasm.
From the cardiovascular system: rarely - orthostatic hypotension and reflex tachycardia, arterial hypertension.
On the part of the endocrine system: galactorrhea, gynecomastia, menstrual irregularities, amenorrhea, weight gain.
On the part of the hematopoiesis system: a small decrease in the number of neutrophils and / or platelets.
Allergic reactions: rhinitis, skin rash, angioedema.
Other: urinary incontinence.
CONTRAINDICATIONS
Hypersensitivity to risperidone.
PREGNANCY AND LACTATION
Use during pregnancy is possible if the expected benefit of therapy for the mother exceeds the potential risk to the fetus. If it is necessary to use lactation, breastfeeding should be discontinued.
APPLICATION FOR FUNCTIONS OF THE LIVER
In schizophrenia with concomitant diseases of the kidneys, an initial dose of 500 Ојg 2 times / day is recommended. If necessary, the dose can be increased to 1-2 mg 2 times / day.
APPLICATION FOR VIOLATIONS OF THE FUNCTION OF KIDNEYS
In schizophrenia with concomitant liver diseases, an initial dose of 500 Ојg 2 times / day is recommended. If necessary, the dose can be increased to 1-2 mg 2 times / day.
APPLICATION FOR CHILDREN
Data on the safety of risperidone in children under the age of 15 years are not available.
APPLICATION IN ELDERLY PATIENTS
In schizophrenia for elderly patients, an initial dose of 500 Ојg 2 times / day is recommended. If necessary, the dose can be increased to 1-2 mg 2 times / day.
SPECIAL INSTRUCTIONS
Use with caution in patients with cardiovascular diseases (including heart failure, myocardial infarction, cardiac muscle conduction abnormalities), as well as during dehydration, hypovolemia or cerebrovascular disorders. In this category of patients, the dose should be increased gradually.
The risk of developing orthostatic hypotension is especially elevated in the initial period of dose selection. If hypotension occurs, consider lowering the dose.
When using drugs that have the properties of antagonists of dopamine receptors, the appearance of tardive dyskinesia, characterized by involuntary rhythmic movements (mainly of the language and / or face) was noted. There are reports that the occurrence of extrapyramidal symptoms is a risk factor for the development of tardive dyskinesia. Risperidone causes the appearance of extrapyramidal symptoms to a lesser extent than the classical antipsychotics. When symptoms of tardive dyskinesia appear, consideration should be given to the abolition of all antipsychotics.
In the case of the development of the NSA, all antipsychotics, including risperidone, should be discontinued.
Caution should be used risperidone in patients with Parkinson's disease, because theoretically possible deterioration of the disease.
It is known that classical antipsychotics reduce the threshold of convulsive readiness. Given this, risperidone is recommended with caution in patients with epilepsy.
Risperidone should be used with caution in combination with other drugs of central action.
With the withdrawal of carbamazepine and other inducers of hepatic enzymes, the dose of risperidone should be reviewed and, if necessary, reduced.
During the period of treatment, patients should be advised to refrain from overeating due to the possibility of weight gain.
Data on the safety of risperidone in children under the age of 15 years are not available.
Impact on the ability to drive vehicles and manage mechanisms
In the period of treatment, before clarifying individual sensitivity to risperidone, patients should avoid driving motor vehicles and other activities that require high concentration and speed of psychomotor reactions.
DRUG INTERACTION
With the simultaneous use of inducers of microsomal liver enzymes, a decrease in the concentration of risperidone in the blood plasma is possible.
With simultaneous use with phenothiazine derivatives, tricyclic antidepressants and beta-adrenoblockers, an increase in the concentration of risperidone in the blood plasma is possible.
When used simultaneously with carbamazepine, the concentration of risperidone in the blood plasma is significantly reduced.
With simultaneous use, risperidone reduces the effects of levodopa and other dopamine receptor agonists.
With simultaneous use with fluoxetine, an increase in the concentration of risperidone in the blood plasma is possible.
