Risdonal, 2 mg 20 pcs.

Risdonal is hypothermic, sedative, antiemetic, antipsychotic.

Pharmacodynamics

Binds also to α₁-adrenoreceptors and with somewhat less affinity to H₁-histaminergic and α₂-adrenergic receptors. It has no tropism to cholinoreceptors. Antipsychotic effect is due to blockade of dopamine D₂ receptors of mesolimbic and mesocortical system. Sedative action is caused by blockade of adrenoreceptors of reticular formation of brain stem; antiemetic action – by blockade of dopamine D₂-receptors of trigger zone of vomiting center; hypothermic action – by blockade of dopamine receptors of hypothalamus. Reduces productive symptomatology (delirium, hallucinations), automatism. Causes less suppression of motor activity and induces catalepsy to a lesser extent than classical antipsychotics (neuroleptics). Balanced central antagonism to serotonin and dopamine may reduce the risk of extrapyramidal symptomatology. Risperidone may cause a dose-dependent increase in plasma prolactin concentrations.

Pharmacokinetics

In oral administration, risperidone is completely absorbed (regardless of food intake) and C_max in plasma is observed after 1-2 h. Risperidone is metabolized with cytochrome P450 IID6 to form 9-hydroxyrisperidone, which has similar pharmacological effects. Risperidone and 9-hydroxyrisperidone constitute an effective antipsychotic fraction. Further metabolism of risperidone consists of N-dealkylation. When ingested, risperidone is excreted with a T_1/2 of about 3 h. The T_1/2 of 9-hydroxirisperidone has been found to be 24 hours. In most patients, the equilibrium concentration of risperidone is observed 1 day after the start of treatment. The equilibrium state of 9-hydroxysperidone is reached in most cases 3-4 days after initiation of treatment. The concentration of risperidone in plasma is proportional to the dose of the drug (within the therapeutic doses). Risperidone is rapidly distributed in the body. The volume of distribution is 1-2 l/kg. In plasma risperidone is bound to albumin and acidic alpha₁-glycoprotein. The fraction of risperidone and 9-hydroxyrisperidone that is bound to plasma protein is 88% and 77%, respectively. It is excreted by the kidneys – 70% (of which 35-45% as pharmacologically active fraction) and with the bile – 14%. High levels of the active antipsychotic fraction in plasma and slow excretion in elderly patients and patients with impaired renal function are noted when administered on a single occasion.

Indications

Active ingredient

Composition

1 film-coated tablet contains:

How to take, the dosage

Inward.

Schizophrenia. Adults and children over 15 years of age: 1 or 2 times a day. The initial dose is 2 mg/day, on the second day the dose should be increased to 4 mg/day. From this point on, the dose can either be kept at the same level or adjusted individually if necessary. Usually the optimal dose is 4-6 mg/day. In some cases, a slower dose increase and lower starting and maintenance doses may be warranted. Doses above 10 mg/day have not been shown to be more effective than lower doses and may cause extrapyramidal symptoms. Because the safety of doses above 16 mg/day has not been studied, doses above this level should not be used. There is no information on use for the treatment of schizophrenia in children under 15 years of age.

Elderly patients and those with liver or kidney disease: The starting dose is 0.5 mg per dose twice daily. The dosage can be increased individually to 1-2 mg 2 times a day.

Anxiety or drug dependence: Recommended daily dose is 2-4 mg.

Behavioral disorders in patients with dementia: the initial dose is 0.25 mg per dose 2 times a day. The dosage may be increased individually to 0.25 mg 2 times a day if necessary, no more often than every other day. For most patients, the optimal dose is 0.5 mg 2 times a day. However, some patients are indicated to take 1 mg twice a day. Once the optimal dose has been reached, once daily dosing may be recommended.

Mania in bipolar disorders: the recommended starting dose is 2 mg 1 time daily. If necessary, this dose may be increased by 2 mg per day, no more often than every other day. For most patients, the optimal dose is 2-6 mg/day.

Behavioral disorders in patients with mental retardation. In patients with a body weight of 50 kg or more: the recommended starting dose is 0.5 mg once daily. If necessary, this dose may be increased by 0.5 mg daily, no more often than every other day. For most patients, the optimal dose is 1 mg daily. However, some patients prefer to take 0.5 mg daily, while others need to increase the dose to 1.5 mg daily.

Patients weighing less than 50 kg: The recommended starting dose is 0.25 mg once daily. If necessary, this dose may be increased by 0.25 mg daily, no more often than every other day. For most patients, the optimal dose is 0.5 mg daily. However, some patients prefer to take 0.25 mg daily, while some need to increase the dose to 0.75 mg daily.

Long-term administration of Risdonal in adolescents should be done under constant medical supervision.

The use in children younger than 15 years is not recommended.

Interaction

Considering that risperidone primarily affects the CNS, it should be used with caution in combination with other centrally acting drugs and with alcohol.

Risperidone decreases the effectiveness of levodopa and other dopamine agonists.

Clozapine decreases the clearance of risperidone.

Carbamazepine has been shown to decrease plasma concentrations of the active antipsychotic fraction (similar effects may be seen with other hepatic enzyme inducers).

Phenothiazines, tricyclic antidepressants and some β-adrenoblockers may increase the plasma concentration of risperidone, but this does not affect the concentration of the active antipsychotic fraction.

Fluoxetine may increase the plasma concentration of risperidone and, to a lesser extent, the concentration of the active antipsychotic fraction, so doses of risperidone should be adjusted.

When using risperidone together with other drugs that are highly bound to plasma proteins, clinically pronounced displacement of any drug from the plasma protein fraction is not observed.

Hypotensive drugs increase the severity of BP reduction with risperidone.

Special Instructions

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

Owing to the α-adrenoblocking effect of risperidone, orthostatic hypotension may occur, especially during initial dose adjustment. If hypotension occurs, dose reduction should be considered. In patients with cardiovascular disease, as well as in dehydration, hypovolemia, or cerebrovascular disorders, the dose should be increased gradually, according to the recommendations (see “Dosage and administration”).

The occurrence of extrapyramidal symptoms is a risk factor for the development of tardive dyskinesia. If signs and symptoms of tardive dyskinesia occur, all antipsychotic medications should be considered for withdrawal. If neuroleptic malignant syndrome occurs, characterized by hyperthermia, muscle rigidity, instability of autonomic functions, impaired consciousness and elevated creatine phosphokinase levels, all antipsychotic drugs, including risperidone, should be withdrawn.

The dose of risperidone should be reduced when carbamazepine and other hepatic enzyme inducers are withdrawn.

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

During treatment, patients should refrain from engaging in potentially hazardous activities requiring increased concentration and quick psychomotor reactions and from drinking alcohol.

Contraindications

With caution: cardiovascular diseases (chronic heart failure, myocardial infarction, cardiac conduction disorders); dehydration and hypovolemia; cerebrovascular disorders; Parkinson’s disease; seizures (including history of seizures).severe renal or hepatic impairment (see dosing guidelines); drug abuse or dependence (see dosing guidelines)

Dosage recommendations; conditions predisposing to development of pirouette tachycardia (bradycardia, electrolyte imbalance, concomitant use of QT prolonging drugs); brain tumor, intestinal obstruction, cases of acute drug overdose, Reye syndrome (antiemetic effect of risperidone may mask symptoms of these conditions); pregnancy, children under 15 years (effectiveness and safety are not established).

Side effects

Nervous system disorders: Insomnia, agitation, anxiety, headache; sometimes – drowsiness, increased fatigue, dizziness, impaired concentration, blurred vision; rarely – extrapyramidal symptoms (tremor, rigidity, hypersalivation, bradykinesia, akathisia, acute dystonia), mania or hypomania, stroke (in elderly patients with predisposing factors), and hypervolemia (either due to polydipsia or inadequate ADH secretion syndrome) tardive dyskinesia (involuntary rhythmic movements primarily of the tongue and/or face), neuroleptic malignant syndrome (hyperthermia, muscle rigidity, instability of autonomic functions, impaired consciousness and increased creatine phosphokinase levels), thermoregulatory disorders and epileptic seizures.

Digestive system disorders: constipation, dyspepsia, nausea or vomiting, abdominal pain, increased liver transaminase activity, dry mouth, hypo- or hypersalivation, anorexia and/or increased appetite, weight gain or loss.

Cardiovascular system disorders: sometimes – orthostatic hypotension, reflex tachycardia or increased BP.

Hematopoietic disorders: neutropenia, thrombocytopenia.

Endocrine system disorders: galactorrhea, gynecomastia, menstrual cycle disorders, amenorrhea, weight gain, hyperglycemia, and exacerbation of pre-existing diabetes.

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

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

Allergic reactions: rhinitis, rash, angioedema, photosensitization.

Others: arthralgia.

Overdose

Symptoms: somnolence, sedation, depression of consciousness, tachycardia, arterial hypotension, extrapyramidal disorders, in rare cases – prolongation of the QT interval.

Treatment: it is necessary to ensure free airway patency for adequate oxygenation and ventilation, gastric lavage (after intubation if the patient is unconscious) and administration of activated charcoal in combination with laxatives. Symptomatic therapy aimed at maintenance of vital body functions.

In order to diagnose possible cardiac rhythm disturbances in time, ECG monitoring should be started as soon as possible. Close medical observation and ECG monitoring is carried out until symptoms of intoxication have completely disappeared. There is no specific antidote.

Similarities