What Is Chlorpromazine?

Chlorpromazine, also known as aminazine, clomazine, and chlorothiodiphenylamine, is a representative drug of phenothiazines. It is an antagonist of central dopamine receptors and has a variety of pharmacological activities.

Drug type: Essential medicines
Drug name: Chlorpromazine

English name: Chlorpromazine
Chinese alias: Aminazine; clomazine; chlorothiodiphenylamine
English alias: Largactil; Torazina; Wintermin

Chemical name of chlorpromazine

N, N-dimethyl-2-chloro-1oH-phenothiazine-1o-propylamine hydrochloride

Molecular formula of chlorpromazine

Chlorpromazine molecular formula

C17H19ClN2S

Chlorpromazine molecular weight

318

Physical and chemical properties of chlorpromazine

Its hydrochloride is commonly used as a white or milky white crystalline powder; it has a slight odor and extremely bitter taste; it is hygroscopic; it gradually changes color when exposed to light; the aqueous solution is acidic. Soluble in water, ethanol or chloroform, insoluble in ether or benzene. Melting point is 194 ~ 198 ° C.

Chlorpromazine pharmacology

This product is a representative drug of phenothiazines. It is an antagonist of central dopamine receptors and has a variety of pharmacological activities.

Antipsychotic effect: It is mainly caused by antagonizing the dopamine receptors in the limbic system related to emotional thinking. The a-adrenergic receptor, which antagonizes the reticular activation system, is related to sedation and stability.

Antiemetic effect: A small dose can inhibit dopamine receptors in the chemically sensitive area of Yannao's vomiting, and a large dose can directly inhibit the vomiting center, resulting in a strong antiemetic effect. But it is not effective for vomiting caused by stimulation of the vestibule.

Cooling effect: Inhibit the body temperature regulation center, reduce the body temperature, and the body temperature can change with the external environment. With larger doses, the patient may be placed in a cold environment (such as an ice pack or bath with ice water), and an "artificial hibernation" state may occur.

Enhance the effects of hypnosis, anesthesia, and sedatives.

Effect on the cardiovascular system: It can antagonize peripheral -adrenergic receptors, directly dilate blood vessels, cause blood pressure to drop, and can cause orthostatic hypotension at high doses, and should be noted. It can also relieve spasm of small arteries and veins, improve microcirculation, and have anti-shock effect. At the same time, because the effect of dilating the large vein is greater than that of the arterial system, it can reduce the preload of the heart and improve heart function (especially left heart failure).

It has certain effects on the endocrine system, such as reducing the release of prolactin inhibitory factors, and breast enlargement and croup. Inhibits gonadotropin release, corticotropin and growth hormone secretion and delays ovulation.

This medicine is easy to be absorbed by oral administration, but the absorption is irregular, and the individual varies greatly. Stomach contents or when taken with anticholinergics (such as benzetholide) can affect their absorption. It has also been reported that benzetholide does not have a significant effect on the absorption of chlorpromazine, but can reduce its efficacy. Oral has the first pass effect. Can reduce blood concentration. The oral drug concentration peaked for 2 to 4 hours and lasted for about 6 hours. After intramuscular injection, the blood concentration peaked rapidly. 90% bound to plasma proteins. The concentration in the brain is 10 times higher than the blood concentration. Can enter the fetus through the placental barrier. 7-Hydroxychloropromazine is still pharmacologically active in the liver by oxidation or binding to glucuronic acid. It is mainly excreted by the kidney and is excreted slowly. t1 / 2 is about 6 to 9 hours.

Chlorpromazine indications

Treatment of mental illness: used to control the symptoms of schizophrenia or other mental illnesses such as excitement, restlessness, hallucinations, delusions, delusions, etc., the efficacy of depression and stiffness is poor. It is not effective for patients with type II schizophrenia, and may even worsen the condition.

Antiemetic: It is effective for vomiting caused by various reasons, such as uremia, gastroenteritis, cancer, pregnancy, and vomiting caused by drugs. It can also treat refractory hiccups. But it is not effective for motion sickness and vomiting.

Low temperature anesthesia and artificial hibernation: It can prevent shock when used for low temperature anesthesia. During artificial hibernation, a hibernation mixture is formulated with pethidine and promethazine for adjuvant treatment of traumatic shock, toxic shock, burns, high fever and thyroid crisis.

Combined with analgesics to treat severe pain in patients with advanced cancer.

treatment of heart failure.

Try to treat giant disease.

Chlorpromazine usage and dosage

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

Chlorpromazine adverse reactions

The main adverse reactions were dry mouth, unclear vision, upper abdominal discomfort, fatigue, drowsiness, constipation, palpitations, occasional lactation, breast enlargement, obesity, and amenorrhea. Orthostatic hypotension can be caused by injection or oral high-dose. It should lie still for 1 to 2 hours after administration. When the blood pressure is too low, norepinephrine or ephedrine can be injected intravenously. But epinephrine is not available to prevent lower blood pressure. It has a certain effect on liver function, which may cause obstructive jaundice and hepatomegaly, which can be recovered after stopping the drug. It can cause extrapyramidal reactions when it is used for a long time, which is a common adverse reaction of antipsychotics. Blocking the dopaminergic striatum substantia nigra conduction pathway produces symptoms such as tremor paralysis syndrome, acute dystonia, and inability to sit still, which can be counteracted by dibenzo, but can reduce the efficacy. This product can also cause a special and lasting dyskinesia, called tardive dyskinesia, which manifests as involuntary stereotypes and does not disappear after stopping the drug. Anticholinergic drugs can aggravate this reaction. Allergic reactions can occur. Common rashes, contact dermatitis, exfoliative dermatitis, granulocytopenia (this reaction is rare and should be discontinued as soon as possible), asthma, purpura, etc. Can cause ocular complications, mainly manifested as corneal and crystal opacities, or increase intraocular pressure. Eye examination should be performed for long-term users, and it should be reviewed once every six months. When using this product in high doses, it is best to wear sunglasses in summer to protect the cornea and crystals.

Chlorpromazine precautions

Patients with liver dysfunction, uremia, hypertension, and coronary heart disease should be used with caution, and liver function should be checked regularly during long-term medication. This product is very irritating. It can cause thrombophlebitis when injected intravenously. Local pain caused by intramuscular injection is more serious. Procaine can be added for deep intramuscular injection. This product can sometimes cause depression, so you should pay attention when you take the medicine. Not recommended for infants under 6 months. The elderly are less tolerant to this class of drugs, and are prone to hypotensive, over-sedated, and tardive dyskinesias that are difficult to eliminate.

Chlorpromazine contraindications

Patients who are allergic to phenothiazines, myelosuppressive patients, glaucoma patients, severely impaired liver function, patients with a history of epilepsy, and patients with coma (especially after using central nervous system inhibitors) are contraindicated.

Chlorpromazine drug interactions

When combined with monoamine oxidase inhibitors and tricyclic antidepressants, the anticholinergic effect of the two is enhanced, and the adverse reactions are aggravated. Combined with lithium carbonate, it can cause blood lithium concentration to increase, leading to dyskinesia, exacerbation of extrapyramidal reactions, encephalopathy and brain damage. When combined with ethanol or other CNS inhibitors, the CNS inhibitory effect is strengthened. In combination with atropine drugs, the anticholinergic effect is enhanced and the adverse reactions are enhanced. Combination with antihypertensive drugs can easily cause orthostatic hypotension; Combination with sutopril has the risk of ventricular arrhythmia. Antacids and benzetholide can reduce the absorption of this product. Phenylbarbital can induce microsomal enzymes in the liver, accelerate excretion of this product, and thus reduce its antipsychotic effect.

Chlorpromazine

Tablet: 12.5mg, 25mg, 50mg; Injection: 1ml: 10mg, 1ml: 25mg, 2ml: 50mg

Introduction of chlorpromazine pharmacopoeia

[Identification] (1) Take about 10mg of this product, add 1ml of water to dissolve, add 5 drops of nitric acid to show red, and gradually light yellow. (2) Take this product, add hydrochloric acid solution (9 1000) to make a solution containing 5µg per 1ml, and measure according to ultraviolet-visible spectrophotometry (Appendix IV A). It has the maximum absorption at the wavelengths of 254nm and 306nm. The absorbance at a wavelength of 254 nm is about 0.46. (3) The infrared light absorption spectrum of this product should be consistent with the control spectrum (spectrum set 391). (4) Identification of chlorides in aqueous solution of this product (Appendix III). [Check] The clarity and color of the solution is 0.50g of this product, and 10ml of water is added. After shaking to dissolve, the solution should be clear and colorless; if it is turbid, compare with No. 1 turbidity standard solution (Appendix B). If it is colored, it should not be darker than other standard colorimetric liquids of Yellow No. 3 or Yellow-Green No. 3 (Appendix A first method), and no other colors should be displayed. Related substances are protected from light. Take 20mg of this product, put it in a 50ml measuring flask, add the mobile phase to dissolve and dilute to the mark, shake well, and use it as the test solution; take a precise amount, and quantitatively dilute with mobile phase to make a solution containing 2µg per ml. Control solution. According to the high performance liquid chromatography (Appendix VD) test, octylsilane bonded silica gel was used as the packed column; acetonitrile-0.5% trifluoroacetic acid (the pH was adjusted to 5.3 with tetramethylethylenediamine) (50:50 ) Is a mobile phase; the detection wavelength is 254 nm. Take 10µl of the control solution and inject it into the liquid chromatograph, and adjust the detection sensitivity so that the peak height of the main component chromatographic peak is about 20% of the full scale. Precisely measure 10 µl each of the test solution and the control solution, and inject them into the liquid chromatograph respectively. Record the chromatogram to 4 times the peak retention time of the main component. If there are impurity peaks in the chromatogram of the test solution, the area of a single impurity peak must not be greater than the area of the main peak of the control solution (0.5%), and the sum of the areas of the peaks of each impurity must not be greater than 2 times (1.0%) the area of the main peak of the control solution. Loss on drying Take this product and dry it to constant weight at 105 ° C. Lose weight should not exceed 0.5% (Appendix L). The ignition residue shall not exceed 0.1% (Appendix N). [Content determination] Take about 0.2g of this product, weigh it accurately, add 10ml of glacial acetic acid and 30ml of vinegar to dissolve, and then titrate with potentiometric titration solution (0.1mol / L) according to the potentiometric titration method (Appendix A). And correct the titration results with a blank test. Each 1 ml of chloric acid titration solution (0.1 mol / L) is equivalent to 35.53 mg of C17H19C1N2S·HC1. [Category] Antipsychotics. [Storage] shading and sealed.

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