Overview【1】
Chlorpheniramine (chlorpheniramine, chlorpheniramine, chlorpheniramine, chlorpheniramine, chlorpheniramine, chlorpheniramine, chlorpheniramine, tripeleniramine) antagonizes H. Receptor, antagonizes the allergic effect of histamine; this drug does not affect the metabolism of histamine, nor does it prevent the release of histamine in the body. It also has anti-M choline receptor and central nervous system inhibitory effects. Generally, it has a weak sedative effect and is mainly used for various allergic diseases. It can also be combined with other Chinese and Western medicines to treat colds, etc.
Pharmacology【2】
First generation antihistamines. It has a strong competitive blocking effect on histamine H on target cells of allergic reactions. The role of receptors. Therefore, it has a good anti-allergic effect. It has certain central depressant and anticholinergic effects. However, it is lighter than other types of traditional antihistamines, so the reactions such as drowsiness, dry mouth, constipation, and thickening of sputum after taking the medicine are less severe. Before the advent of new generation antihistamines, it was the most widely used antihistamine in clinical practice.
Pharmacokinetics【2】
Chlorpheniramine is rapidly absorbed from the gastrointestinal tract after oral administration, takes effect in about 30 minutes, reaches the highest blood concentration in 1 to 2 hours, and can maintain its efficacy for 3 to 6 hours. Metabolized by the liver and excreted through urine, feces, and sweat. Breastfeeding women may also excrete part of it through breast milk. Medications taken during pregnancy can affect the fetus through cord blood.
Indications
Used for allergic diseases of skin and mucous membranes, acute and chronic urticaria, angioedema, perennial allergic rhinitis, seasonal rhinitis, allergic conjunctivitis, insect sting dermatitis, contact dermatitis, etc. . It is mostly used for allergic diseases in children. It is also often effective for upper respiratory tract infections and gastrointestinal allergic symptoms in children. It can also be used to prevent blood transfusion reactions and drug allergies.
Clinical application in ophthalmology
Allergic conjunctivitis and intraocular lens surgery.
Drug interactions【2】
1． This product can enhance the effects of amantadine, anticholinergics, haloperidol, phenothiazines and sympathomimetics.
2． It is not suitable to be used in combination with peterines, atropine, etc.
3． If you drink alcohol or use central nervous system depressants in your eyes at the same time, the efficacy of this product will be enhanced.
4. This product should not be mixed with aminophylline for injection.
Usage and dosage
1． oral. The dosage for adults is 4 to 8 mg, 3 times a day. 0.35rag/(kg·d) for children. Take 3 or 4 times.
2. For patients with mild symptoms or evening attacks, it is advisable to reduce medication during the day. Take once before going to bed.
3． For patients with severe vomiting, a single oral dose may be administered. Dissolve it into 50-100ml with warm water and infuse it through the rectum.
Adverse reactions【2】
1. The adverse effects of this drug are similar to but milder than those of other first-generation antihistamines. It is rare to cause insomnia, irritability and other central nervous system excitement symptoms, and may even induce epilepsy. It should also be used with caution in infants, young children, pregnant women and lactating women.
2. Patients with chronic allergic diseases should not use this medicine alone for a long time. to prevent the development of drug resistance.
3． Elderly patients are prone to dizziness and headaches and other adverse reactions, and patients with hypotension are also prone to dizziness and headaches, so they should be used with caution.
4． When overdose occurs and toxic reactions occur, vomiting, gastric lavage, and catharsis should be induced in time to speed up the excretion of the drug. If respiratory and circulatory failure occurs, artificial respiration and oxygen inhalation should be performed. Central stimulant drugs should be avoided. If necessary, intravenous infusion of norepinephrine can be used to maintain blood pressure, but epinephrine should not be used. Do not use histamine injection as an antidote during rescue.
5. Using it together with sedatives, hypnotics or tranquilizers, or drinking alcohol at the same time can deepen the central depressant effect, so it should be stopped during the medication period.
Contraindications
1. Drivers, people working at heights, machinery operators and athletes before competition should not take this medicine.
2. Avoid use in patients with epilepsy. People with glaucoma and prostatic hypertrophy should use with caution.
Notes
1. Although this drug is an antihistamine and is widely used in the treatment of allergic diseases, there are also a few patients who have drug allergies to this drug. After taking the drug, they may develop rashes, itching, gastrointestinal allergies, etc., and even cause Those who have had changes in their blood picture after taking this medicine. Therefore, you should not relax your vigilance against drug allergies during the use of this drug.
2. This drug should not be combined with pethidine, atropine and other drugs, nor should it be mixed with aminophylline for injection.
(3) It is forbidden for those who drive vehicles, boats or perform dangerous operations.
(4) People who are allergic to other antihistamines may be allergic to this drug.
(5) Use with caution in the following conditions: bladder neck obstruction, pyloric duodenal obstruction, pyloric stenosis due to peptic ulcer, cardiovascular disease, glaucoma, high winning pressure, hypertensive crisis, hyperthyroidism, When signs of prostatic hypertrophy are obvious.
(6) The elderly should pay attention to appropriate dose reduction.
New clinical uses【3】
1. Treatment of mumps: Some people have used chlorpheniramine and cimetidine to treat patients with mumps, and they have also achieved significant results. Compared with the control group treated with morpholine, isatis root, etc., they can promote recovery and shorten the course of the disease. Treatment method: Orally take chlorpheniramine 2 to 4 mg, 2 to 3/d; cimetidine 20rag/(kg·d) orally, divided into 2 or 3 times. Use until fever subsides and parotid gland swelling subsides, no longer than 7 days. The author believes that chlorpheniramine has a strong effect on the increase in capillary permeability and edema caused by histamine.��Inhibitory effect and antagonizes histamine to dilate blood vessels; while cimetidine can be antiviral, and the two have a synergistic effect. Therefore, the combined use of the two drugs in the treatment of patients with mumps has a satisfactory effect.
2. To treat anxiety disorders, some people have used chlorpheniramine to treat patients with anxiety disorders, with a total effective rate of 93.7%. Usage: Take chloramine orally, 4 to 6 mg each time, 2 to 3/d, and Yan Yingjing for 2 to 3 courses. The intervals between treatments can be 3 to 5 days.
3． Treatment of chronic hepatitis According to reports, 193 patients with chronic hepatitis were treated with chlorpheniramine, and GPT returned to normal in 171 of them. Treatment method: Take 16 mg of chlorpheniramine orally each time before going to bed every night.
4． Adjuvant treatment of pneumonia in children: Most children with pneumonia caused by viral infection have low cellular immune function and a relatively low T lymphocyte index. Viral infection stimulates allergic reactions in pulmonary capillaries, and mast cells release inflammatory mediators such as histamine, causing capillary leakage, tissue edema, and bronchiolar spasm. Chlorpheniramine and cimetidine are Ht and H2 receptor blocking drugs respectively. The combination of the two drugs can effectively compete with histamine for receptors and protect the body. In addition, amitidine also regulates immunity. It has antiviral and antiviral effects, can enhance the body’s immune function and speed up recovery from infection. Usage: On the basis of conventional treatment, chlorpheniramine 2mg/d and cimetidine 20mg/kg can be added; take 2-3 times orally. Use 5d continuously. The total effective rate was 92%, and the difference was significant compared with the control group (total effective rate 48%).
Synthetic route
References
[1]Wang Shuqing, Ju Weihua, Zhou Xuanxiu, editors-in-chief, Common Adverse Drug Reactions and Treatment (Western Medicine Volume), Military Medical Science Press, 2013.06, page 332
[2] Editor-in-Chief Zhang Renjun et al., Practical Ophthalmic Pharmacology, People’s Military Medical Press, 2015.09, page 349
[3]Li Shiwen, edited by Kang Manzhen; edited by Li Yi, Li Lun, Li Shiwen, Zou Qingbo, Zhang Yuan, and Kang Manzhen, Old Drugs with New Uses, 5th Edition, People’s Military Medical Press, 2013.09, page 419
