Risperidone, 4 mg 20 pcs

Risperidone is an antipsychotic (neuroleptic), a benzisoxazole derivative. It also has sedative, antiemetic and hypothermic effects. Selective monoaminergic antagonist, has high tropism to serotonergic 5-NT2 and dopaminergic D2 receptors. It also binds to alpha1-adrenoreceptors with slightly lower affinity to H1-histaminergic and alpha2-adrenergic receptors. It has no tropinity to cholinoreceptors.

Antipsychotic action is caused by blockade of dopamine D2-receptors of mesolimbic and mesocortical system. Sedative action is caused by the blockade of adrenoreceptors of reticular formation in brain stem; antiemetic action – by the blockade of dopamine D2-receptors of trshter zone of vomiting center; hypothermic action – by the blockade of dopamine receptors of hypothalamus.
It suppresses productive symptomatology (delirium, hallucinations, aggressiveness), automaticity. Causes less suppression of motor activity and induces catalepsy to a lesser extent than classical antipsychotic drugs (neuroleptics). Balanced central antagonism to serotonin and dopamine may reduce the propensity for extrapyramidal side effects and extend the therapeutic effects of the drug to include negative and affective symptoms of schizophrenia.
May induce a dose-dependent increase in plasma prolactin concentration.

Pharmacokinetics

Absorption is rapid and complete. Food does not affect the completeness and rate of absorption. ÒCmax of risperidone is 1 hour; that of 9-hydroxyrisperidone is 3 hours (with high activity of CYP2D6 isoenzyme) and 17 hours (with low activity of CYP2D6 isoenzyme). Plasma concentrations of risperidone are proportional to the dose of the drug. The equilibrium concentration of risperidone in most patients is reached within 1 day, 9-hydroxy-risperidone – after 4-5 days.
Risperidone is rapidly distributed in the body. It penetrates the central nervous system (CNS), breast milk. The volume of distribution is 1-2 l/kg. Binding to plasma proteins (with alpha1-acid glycoprotein and albumin) of risperidone is 90%, 9-hydroxyrisperidone – 77%.
Metabolized by CYP2D6 isoenzyme to the active metabolite – 9-hydroxyrisperidone (risperidone and 9-hydroxyrisperidone form the active antipsychotic fraction). Another way of metabolism of risperidone is N-dealkylation.
The elimination half-life of risperidone is 3 hours; that of 9-hydroxyrisperidone and the active antipsychotic fraction is 20-24 hours.
Excreted by the kidneys (70%: of which 35-45% – as pharmacologically active fraction) and the intestine (14%).
Study of single drug administration showed higher plasma concentration and slower excretion in elderly patients and in patients with renal insufficiency. Excretion is slower in elderly patients and in patients with renal insufficiency.
In hepatic insufficiency, the plasma content of risperidone is increased by 35%.

Indications

Active ingredient

Composition

Active ingredient: risperidone 4 mg;

Auxiliary substances: calcium hydrophosphate dihydrate, povidone (plasdon K 29/32 or collidone 30), pregelatinized starch (C*Pharm starch), magnesium stearate, microcrystalline cellulose;

Film coating composition: AQ-02003 (hypromellose 2910 (hydroxypropyl-methylcellulose 2910), macrogol-6000 (polyethylene glycol 6000), titanium dioxide).

How to take, the dosage

It is administered orally. Adults and children over 15 years of age are prescribed 1 or 2 times a day.
Schizophrenia. The initial dose is 2 mg per day. On the 2nd day, up to 4 mg per day. From then on, if necessary, the dose may either be maintained at the same level or adjusted individually in the range of 4-6 mg per day.
Doses above 10 mg per day have not shown a higher efficacy compared to lower doses and may cause extrapyramidal symptoms. The maximum daily dose is 16 mg.
Behavioral disorders in patients with dementia: The optimal dose is 1 mg once daily.
Bipolar mania disorders: the initial dose is 2 mg per day for 1 administration. Increase the dose (by 2 mg per day) – not more often than every other day. The optimal dose is 2-6 mg per day.
Behavioral disorders in patients with mental retardation or with destructive tendencies dominating in the clinical picture. Patients with a body weight of 50 kg or more. The optimal dose is 1 mg per day.
It is recommended to halve both the initial dose and subsequent dose increases in elderly patients and in patients with renal or hepatic insufficiency (if adequate dosage form is necessary).

Interaction

Risperidone decreases the effectiveness of levodopa and dopamine agonists. Phenothiazines, tricyclic antidepressants and beta-adrenoblockers increase the plasma concentration of risperidone (does not affect the concentration of the active antipsychotic fraction).

Concomitant administration of carbamazepine and other inducers of microsomal enzymes decreases the concentration of the active antipsychotic fraction of risperidone in plasma. Clozapine decreases clearance of risperidone.

When used concomitantly with risperidone, ethanol, drugs that depress the central nervous system (CNS) lead to additive suppression of CNS function.

Hypotensive drugs increase the severity of BP reduction with risperidone.

Fluoxetine may increase the plasma concentration of risperidone (to a lesser extent, its active antipsychotic fraction).

Special Instructions

In schizophrenia, at the beginning of treatment with risperidone, it is recommended that previous therapy be gradually withdrawn if clinically warranted. If patients are transferred from therapy with depot forms of antipsychotic medication, it is recommended that administration be started instead of the next scheduled injection. The need for continuation of current antiparkinsonian drug therapy should be evaluated periodically.

The risk of mania or hypomania can be significantly reduced with low doses of risperidone or with gradual increases.
If orthostatic hypotension occurs, especially during the initial period of dose adjustment, dose reduction should be considered. In patients with diseases of the cardiovascular system, as well as in dehydration, hypovolemia or cerebrovascular disorders, the dose of risperidone should be increased gradually. If signs and symptoms of tardive dyskinesia occur, withdrawal of all antipsychotic medications should be considered. In malignant neuroleptic syndrome – all antipsychotic medications, including risperidone, should be withdrawn.

When withdrawing carbamazepine and other microsomal enzyme inducers, the dose of risperidone should be reduced.

Patients should be advised to refrain from overeating due to the possibility of weight gain.

During treatment, caution should be exercised when driving vehicles and engaging in other potentially hazardous activities requiring increased concentration and quick psychomotor reactions.

Contraindications

With caution: Used in brain tumor, intestinal obstruction, drug overdose, Reye syndrome (the antiemetic effect of risperidone may mask the symptoms of these conditions), diseases of the cardiovascular system (chronic heart failure, atrioventricular block, myocardial infarction), dehydration, disorders of the brain circulation, hypovolemia, Parkinson’s disease, convulsions (incl.

Parkinson’s disease, seizures (including history), drug abuse, drug addiction, severe renal failure, severe hepatic failure, conditions predisposing to development of pirouette-type tachycardia (bradycardia, electrolyte imbalance, concomitant use of QT interval prolonging drugs), pregnancy.

Side effects

Central nervous system disorders: insomnia, agitation, anxiety, headache, somnolence, increased fatigability, dizziness, decreased ability to concentrate, blurred vision, extrapyramidal symptoms (tremor, rigidity, hypersalivation, bradykinesia, akathisia, acute dystonia), mania or hypomania, stroke (in elderly patients with predisposing factors). In schizophrenic patients – hypervolemia (either due to polydipsia or due to inadequate antidiuretic hormone secretion syndrome), tardive dyskinesia (involuntary rhythmic movements, mainly of the tongue and/or face), malignant neuroleptic syndrome (hyperthermia, muscle rigidity, instability of autonomic functions, impaired consciousness and increased creatinphosphokinase activity), thermoregulation disorders, epileptic seizures.

Digestive system disorders: constipation, dyspepsia, nausea or vomiting, abdominal pain, increased liver transaminase activity, dry mouth, hyposalivation or hypersalivation, anorexia.

Cardiovascular system: orthostatic hypotension, reflex tachycardia or increased blood pressure (BP).

Hematopoietic disorders: neutropenia, thrombocytopenia.

Endocrine system disorders: galactorrhea, gynecomastia, menstrual irregularities, amenorrhea, weight gain or loss, hyperglycemia or exacerbation of pre-existing diabetes.

Urogenital system disorders: priapism, erectile dysfunction, ejaculation disorders, orgasm disorders, including anorgasmia, urinary incontinence.

Allergic reactions: itching, rash, angioedema.

Skin disorders: dry skin, hyperpigmentation, seborrhea, photosensitization.

Others: arthralgia, rhinitis.

Overdose

Symptoms: drowsiness, sedation, tachycardia, decreased BP, extrapyramidal disorders, rarely – QT interval prolongation.

Treatment: ensure free airway to ensure adequate oxygen supply and ventilation, gastric lavage (after intubation if the patient is unconscious) and administration of activated charcoal along with a laxative. Start ECG monitoring immediately to detect possible arrhythmias. There is no specific antidote. It is necessary to carry out symptomatic therapy aimed at maintaining vital body functions. In case of BP decrease and vascular collapse – intravenous infusion of infusion solutions and/or adrenostimulants. In case of acute extrapyramidal symptoms – anticholinergic drugs. Continuous medical observation and monitoring should be continued until the symptoms of intoxication disappear.

Similarities