What Is Risperidone?

Risperidone is used to treat acute and chronic schizophrenia. In particular, it has good curative effect on positive and negative symptoms and their associated emotional symptoms (such as anxiety, depression, etc.). It can also reduce the emotional symptoms associated with schizophrenia. For patients who are effective in the acute phase, this product can continue to exert its clinical effect in the maintenance phase.

Drug type: Essential medicines
Drug name: Risperidone

English name: Risperidone
Chinese alias: Risperidone; risperidone; risperidone
English alias: Risperidal

Risperidone chemical name

3- [2- [4- (6-fluoro-1,2-benzoisoxazol-3-yl) -1-piperidinyl] ethyl] -6,7,8,9-tetrahydro-2 -Methyl-4H-pyrido [1,2-] pyrimidin-4-one

Risperidone molecular structure

Risperidone molecular formula

C23H27FN402

Risperidone molecular weight

410

Physicochemical properties of risperidone

White crystalline powder, melting point 170.0 ° C.

Risperidone pharmacology

This product is a phenylpropisoxazole derivative, which is a new generation of antipsychotics. Has a high affinity for 5-HT2 receptors and dopamine D2 receptors. This product can also bind to the 1 receptor, has lower affinity to the H1 receptor and 2 receptor, and does not bind to the cholinergic receptor. This product is a powerful D2 receptor antagonist that can improve the positive symptoms of schizophrenia; however, it has less motor function inhibition and tonic syncope than classic antipsychotic drugs. The balance of 5-HT and dopamine antagonistic effects on the central system can reduce the possibility of extrapyramidal side effects and extend its therapeutic effect to the negative and emotional symptoms of schizophrenia. This product is rapidly and completely absorbed orally, and its absorption is not affected by food. Peak blood concentration is reached after 1 hour of administration, and the elimination half-life is about 3 hours. Most patients reach steady state within 1 day. It is partially metabolized to 9-hydroxyrisperidone in the body and has pharmacological activity. Its elimination half-life is 24 hours. Most of this product is excreted from the kidneys. Elderly patients and patients with renal insufficiency have slower clearance.

Risperidone indications

For the treatment of acute and chronic schizophrenia. In particular, it has good curative effect on positive and negative symptoms and their associated emotional symptoms (such as anxiety, depression, etc.). It can also reduce the emotional symptoms associated with schizophrenia. For patients who are effective in the acute phase, this product can continue to exert its clinical effect in the maintenance phase.

Risperidone usage and dosage

Due to different dosage forms and specifications, please read the drug instructions carefully or follow the doctor's advice.

Risperidone adverse reactions

Extrapyramidal side effects caused by classic antipsychotics are few and mild. The main common adverse reactions were dose-related extrapyramidal symptoms, amenorrhea, galactorrhea, and sexual dysfunction due to elevated prolactin levels. There may be anxiety, drowsiness, dizziness, nausea, constipation, indigestion, rhinitis, rash and so on.

Risperidone contraindications

Prohibited in people allergic to this product and children under 15 years of age.

Risperidone precautions

Use with caution in patients with Parkinson's syndrome and epilepsy. The dose should be reduced for the elderly and patients with heart, liver and kidney diseases. Avoid driving or performing mechanical operations during medication. Not suitable for pregnant women and lactating women.

Risperidone drug interactions

Phenothiazines, tricyclic antidepressants and some beta receptor antagonists will increase the blood concentration of this product. Carbamazepine and other liver drug enzyme inducers will reduce the plasma concentration of the active ingredient of this product. The liver drug enzyme inhibitors can cause the plasma concentration of this product to increase. This product can aggravate the adverse reactions of tricyclic antidepressants. Combined with lithium, it will cause a series of encephalopathy symptoms, extrapyramidal symptoms and dyskinesia. Combination with tramadol and zotepine may increase the risk of seizures. Combined with monoamine oxidase inhibitors, it can aggravate the latter's adverse reactions.

Risperidone preparation

Tablet: 1mg, 2mg

Introduction to risperidone pharmacopoeia

[Identification] The retention time of the main peak of the test product and the main peak of the reference product are the same in the chromatogram recorded under the item containing children's measurement. [Inspection] Take one piece of this product, put it in a test tube with a stopper, and add 10ml of the internal standard solution under the content determination item (2mg tablet plus 20ml). From now on, the content should be determined according to the law and should meet the requirements (XE of Appendix 2 of the Chinese Pharmacopoeia 2000 Edition). Take this product for dissolution, according to the dissolution method (Chinese Pharmacopoeia 2000 Edition Appendix II XC third method), using 100ml 0.1mol / L hydrochloric acid solution as the solvent, the rotation speed is 75 revolutions per minute, according to the law, after 45 minutes Take a proper amount of solution, centrifuge, and take the supernatant as the test solution. Another appropriate amount of risperidone reference substance was precisely weighed and dissolved in a 0.1 mol / L hydrochloric acid solution to make a solution containing 10 µg per 1 ml as a reference solution. According to the method under the content determination method, accurately measure 50l each of the reference solution and the test solution, inject them into the liquid chromatograph, record the chromatogram, and calculate the dissolution amount of each piece by the peak area according to the external standard method. The limit is 80% of the labeled amount and should meet the requirements. Others shall comply with the relevant provisions under the tablet [Chinese Pharmacopoeia 2000 Edition Appendix II IA). [Content determination] Determination according to high performance liquid chromatography (Chinese Pharmacopoeia 2000 edition Appendix II IA) determination. Chromatographic conditions and system suitability test. Octadecylsilane bonded silica gel was used as filler, 2% diethylamine solution (pH adjusted to 5.2 ± 0.1 with glacial acetic acid)-acetonitrile (7: 3) as mobile phase; detection wavelength For 238mn. The number of theoretical plates is calculated based on the risperidone peak, which should not be less than 2000, and the resolution of the risperidone peak and the internal standard substance peak should be greater than 4.0. Preparation of internal standard solution Take about 0.13g of hydroxyphenethyl, accurately weighed, put in a 200ml measuring bottle, add methanol to dissolve and dilute to the mark, shake well, take an appropriate amount with precision, add 0.05mol / L hydrochloric acid solution Each 1ml contains 65µg of the solution. Take 20 tablets of this product by measuring method, accurately weigh, grind fine, accurately weigh an appropriate amount (about 5mg of risperidone), put it into a 50ml measuring bottle, add 30ml of internal standard solution, and oscillate for 30 minutes with ultrasound, and cool to room temperature Add the internal standard solution to the scale, shake well, centrifuge, and take the mash solution as the test solution. Another take risperidone reference solution. Precisely measure 10 l of each of the two solutions, and inject them into the liquid chromatograph, record the chromatogram, and calculate the peak area according to the internal standard method. [Category] Antipsychotics. [Storage] Sealed and stored at 15 ~ 30 .

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