What Is Clonazepam?
1,3-dihydro-7-nitro-5- (2-chlorophenyl) -2H-1,4-benzodiazepine-2one
- Clonazepam, is mainly used for the treatment of epilepsy and convulsions, and is effective for all types of epilepsy, especially for microseizures and myoclonic seizures. Intravenous treatment of status epilepticus. can be used to treat anxiety and insomnia. It is also effective for chorea. It also has a certain effect on drug-induced ADHD, chronic multiple seizures, stiff-man syndrome, and various types of neuralgia.
- Drug name
- Clonazepam
- Drug type
- Essential medicines
- English name
- Clonazepam
- Chinese alias
- Clonidine
- English alias
- Clonopin; Antelepsin; Clonex
Clonazepam chemical name
- 1,3-dihydro-7-nitro-5- (2-chlorophenyl) -2H-1,4-benzodiazepine-2one
Molecular formula of clonazepam
Clonazepam molecular formula
- C15H10ClN3O3
Clonazepam molecular weight
- 315
Physical and chemical properties of clonazepam
- It is light yellow or light yellow crystalline powder; almost odorless and tasteless. It is slightly soluble in acetone or chloroform, slightly soluble in methanol or ethanol, and almost insoluble in water. Melting point is 237 ~ 240 ° C.
Clonazepam pharmacology
- The effect is similar to that of azepam and nitrazepam. But the anticonvulsant effect is 5 times stronger than the former two, and the effect is rapid. Similar to the central inhibitory effect of other BDZ drugs, it accelerates the influx of chloride ions in nerve cells, hyperpolarizes the cells, and reduces the excitability of nerve cells. At the same time, it also has a certain effect on glutamate decarboxylase, so it has a broad-spectrum antiepileptic effect. This product also has anti-anxiety, hypnotic and central muscle relaxation effects. Oral absorption is good, and the plasma concentration reaches 2 to 4 hours. The plasma half-life is 20 to 40 hours. High fat solubility, easy to cross the blood-brain barrier. Taken orally for 30 to 60 minutes, and the effect can last for 6 to 8 hours. Almost all are metabolized in the liver, mainly through the CYP3A enzyme. Metabolites are excreted in the urine in free or bound form, with only minimal amounts excreted in the form of the original drug.
Clonazepam indications
- It is mainly used for the treatment of epilepsy and convulsions, and it is effective for all types of epilepsy, especially for microseizures and myoclonic seizures. Intravenous treatment of status epilepticus. can be used to treat anxiety and insomnia. It is also effective for chorea. It also has a certain effect on drug-induced ADHD, chronic multiple seizures, stiff-man syndrome, and various types of neuralgia.
Clonazepam usage and dosage
- Due to different dosage forms and specifications, please read the drug instructions carefully or follow the doctor's advice.
Clonazepam adverse reactions
- Common drowsiness, dizziness, headache, excitement, restlessness, fatigue, slurred speech, and behavioral disorders. Tolerance and dependence for long-term medication. Long-term medication can cause weight gain, depression, and sexual dysfunction.
Clonazepam contraindications
- Allergic to this product and other BDZ drugs, glaucoma patients are prohibited. It has teratogenic effect and is forbidden in pregnant women.
Clonazepam precautions
- The dosage should be gradually increased to the maximum tolerated amount, and it should be gradually reduced when the drug is stopped. liver and kidney dysfunction should be used with caution. Intravenous injection, its respiratory and cardiostatic effects are stronger than diazepam, so you need to pay attention. Affects the central nervous system and physical development of young children, so this product is not suitable for long-term use in children with epilepsy. The elderly should be careful when using it.
Clonazepam drug interactions
- Combined with barbiturates and primidone, this product can increase sleepiness.
Clonazepam preparation
- Tablet: 0.5mg, 2mg
Introduction to Clonazepam Pharmacopoeia
- [Identification] (1) Take about 10mg of this product, add 1ml of dilute hydrochloric acid to dissolve it, and add drop of bismuth potassium iodide test solution, which will produce orange-red precipitate. After standing, the precipitate becomes darker. (2) Take this product and add 0.5% sulfuric acid in ethanol solution to make a solution containing about 10µg per ml. According to ultraviolet-visible spectrophotometry (Appendix IV A), it has maximum absorption at the wavelengths of 252nm and 307nm. . (3) The infrared absorption spectrum of this product should be consistent with the control spectrum (spectrum set 502). [Inspection] Take this product, dissolve it with solvent [tetrahydrofuran-methanol-water (10:42:48)] and dilute it quantitatively to make a solution containing 0.5mg per 1ml as the test solution; take an appropriate amount of precision , Quantitatively dilute with solvent to make a solution containing 0.5 µg per 1 ml as a control solution. According to the high performance liquid chromatography (Appendix VD) test, using octylsilane bonded silica gel as a filler, ammonium phosphate solution (take 6.6g of ammonium phosphate, add 950ml of water to dissolve, use 0.5mol / L phosphoric acid solution or 1mol / L sodium hydroxide solution was adjusted to pH 8.0, and water was added to 1000 ml) -methanol-tetrahydrofuran (48:42:10) as a mobile phase, and the detection wavelength was 254 nm. Take an appropriate amount of 2-amino-2'-chloro-5-nitrobenzophenone reference substance (impurity I), add the solution for the test solution to dissolve and make a solution containing 0.5 µg per 1 ml, as the system suitability test solution. Take 20µl of the system suitability test solution and inject it into the liquid chromatograph. Record the chromatogram. The resolution of the clonazepam peak and the impurity I peak should be greater than 8.0. Take the reference solution and inject it into the liquid chromatograph, adjust the detection sensitivity so that the peak height of the main component peak is about 20% of the full range; accurately measure 20 l each of the reference solution and the test solution, and inject them into the liquid chromatograph and record the chromatography The figure shows 3 times the peak retention time of the main component. If there is a chromatographic peak in the chromatogram of the test solution that has the same retention time as the impurity I, the peak area must not be greater than the main solution area of the control solution (0.1%), and the area of the other single impurity peaks must not be more than twice the main solution area (0.2%), the sum of the peak areas of each impurity should not be greater than 5 times (0.5%) the main peak area of the control solution. Loss on drying: Take this product and dry to constant weight at 105 ° C. Lose weight should not exceed 0.5% (Appendix L). Take 1.0g of this product and check it according to law (Appendix N). The remaining residue should not exceed 0.1%. The heavy metal shall be taken as the residue left under the burning residue, and shall be inspected in accordance with the law (Appendix H Second Law). The content of heavy metal shall not exceed 20 parts per million. [Content determination] Take about 0.25g of this product, weigh it accurately, add 35ml of acetic anhydride to dissolve, and then titrate with potentiometric titration solution (0.1mol / L) according to the potentiometric titration method (Appendix A) The results are corrected with a blank test. Each 1ml of perchloric acid titration solution (0.1mol / L) is equivalent to 31.57mg of C15H10ClN3O3. [Category] Anxiolytics, anticonvulsants. [Storage] shading and sealed.