What Are the Most Common Chlorpheniramine Side Effects?

Chlorpheniramine is used for allergic rhinitis, cold and sinusitis, and allergic skin disorders such as urticaria, allergic drug rash or eczema, angioedema, and itching caused by insect bites.

Drug Name: Chlorpheniramine
Drug type: Essential medicines
English name: Chlorphenamine

Chinese alias: Chlorpheniramine maleate
English alias: Chlorpheniramine; Chlophenamin
Molecular formula: C16H19ClN2
Molecular weight: 274.79

Brief introduction of chlorpheniramine

Chlorpheniramine Regulatory Information

China

Hazardous Chemicals

Physical and chemical properties of chlorpheniramine

Shape: This product is oily liquid, BP 0.5 159-161 . Its maleate is a white crystalline powder, MP 132-135 ° C, (130-135 ° C). Soluble in water (1: 4), ethanol (1:10) and chloroform (1:10); slightly soluble in ether

Density: 1.938g / cm ³

Melting point: 240-241ºC

Boiling point: 532.5ºC at 760mmHg

Flash point: 275.9ºC

Storage conditions: Store lightly, store in a well-ventilated place, away from open flames, high temperatures, and sunlight, and store separately from oxidants and flammable materials

Chlorpheniramine Safety Information

Danger category: 1.1

Customs Code: 2921499090

Dangerous Goods Transport Code: 0079

WGK Germany: 3

Danger category code: R2

Safety instructions: 35-36-45-61

Dangerous goods mark: E; T +; N

Use of chlorpheniramine

Used in the manufacture of ammunition and for the analysis of potassium salts ^[1] .

Chlorpheniramine Drug Description

Chlorpheniramine classification

Antiallergic Drugs> Antihistamines

Chlorpheniramine

1. Tablets: 4mg each

2. Injection: 10mg / 1ml, 20mg / 2ml

Chlorpheniramine pharmacological effects

Chlorpheniramine is an H1 receptor antagonist and its chemical structure is a hydrocarbon amine. It can competitively block the histamine H1 receptor on allergic target cells, so that histamine cannot bind to the H1 receptor, thereby inhibiting the allergic reaction caused by it. But chlorpheniramine does not affect the metabolism of histamine, nor does it prevent the release of histamine in the body. Chlorpheniramine also has a central and anticholinergic effect, so after taking the drug, it has drowsiness, dry mouth, constipation, thickened sputum and dry nasal mucosa. After a long period of clinical practice, it is believed that chlorpheniramine has a strong antihistamine effect, a small dosage and small side effects. The antihistamine effect of chlorpheniramine is stronger than that of diphenhydramine and promethazine, while the central inhibitory effect is weak and the anticholinergic effect is weak. Due to mild side effects such as drowsiness, it is suitable for children and patients who need to work during the day. Chlorpheniramine has the effect of reducing tracheal secretion and gastric acid secretion. Before the advent of a new generation of antihistamines, they were the most commonly used antihistamines in clinical practice ^[2] .

Chlorpheniramine pharmacokinetics

There were 13.2% of the original form in the urine, 5.8% of N-desmethylparmin, another chlorpheniramine N-oxide, and two unidentified metabolites. Most of the drugs are excreted as polar metabolites. Chlorpheniramine is metabolized by the liver and excreted by urine, stool, and sweat. Breastfeeding women can also excrete part of their milk. Medications for pregnant women can affect the fetus through cord blood ^[2] .

Chlorpheniramine indications

There were 13.2% of the original substance in the urine, 5.8% of N-desmethylparmin, another chlorpheniramine N-oxide, and two unidentified metabolites. Most of the drugs are excreted as polar metabolites. Chlorpheniramine is metabolized by the liver and excreted by urine, stool, and sweat. Breastfeeding women can also excrete part of their milk. Medications for pregnant women can affect the fetus through cord blood ^[2] .

Chlorpheniramine Usage and Dosage

1. Oral, 4mg per adult, 3 times a day. Children take 0.3 mg / kg daily in 4 divided doses.

2. Intramuscular or subcutaneous injection, 10 mg per adult, 3 times a day. Children were injected subcutaneously 0.35mg / kg daily in 4 injections.

3. Intravenous injection, 10 mg per adult, once a day. Patients with vomiting can dissolve 1 dose in 50 to 100 ml of warm water and retain it through the rectum after perfusion ^[2] .

Chlorpheniramine adverse reactions

1. Sometimes there is a slight dry mouth, dizziness, nausea and other reactions, and the sleepiness effect is slight.

2. When the dosage is over acute poisoning, central depression often occurs in adults. When children are poisoned, they are mostly excited. When respiratory failure, artificial respiration, oxygen and other supportive therapies can be used. If necessary, intravenous infusion of norepinephrine can be used to maintain blood pressure, but adrenaline is not suitable. Do not use histamine injection as an antidote during rescue. ^[2]

Clophenamine Contraindications

1. Prohibited for those who are allergic to chlorpheniramine.

2. Newborn, premature, pregnant and lactating women are prohibited.

3. The center is disabled if it is in an excessively suppressed state.

4. Narrow-angle glaucoma, prostatic hypertrophy, bladder neck obstruction, myasthenia gravis, gastric ulcer, pyloric and duodenal obstruction, and epilepsy are prohibited ^[2] .

Chlorpheniramine notes

The injection is irritating, too fast intravenous injection can cause hypotension or central nervous excitement. should not be mixed with aminophylline for injection. Cross-allergy, allergic to other antihistamines or ephedrine, epinephrine, isoproterenol, norepinephrine and iodine may be allergic to this drug. Drivers of cars, ships, and aircraft, and operators of precision instruments are prohibited from taking antihistamines with central nervous system suppression before work. Patients with angle-closure glaucoma, urinary retention, benign prostatic hyperplasia, pyloric duodenal obstruction, and epilepsy should be used with caution. The new antihistamines have less anticholinergic side effects. Use with caution in pregnant and lactating women. Newborns and preterm infants are more sensitive to the anticholinergic effects of this class of drugs and should not be used. The elderly are more sensitive to adverse reactions to histamines, and are prone to adverse reactions such as hypotension, insanity, dementia and dizziness when using this product.

Chlorpheniramine drug interactions

Combination with alcohol and other central nervous system inhibitors, such as barbiturates, hypnotics, opioid analgesics, anxiolytic sedatives, and antiepileptic drugs, can increase the central nervous system inhibitory effect of antihistamines, but new This interaction is weaker with antihistamines. Combination with other anticholinergic drugs, such as atropine, tricyclic antidepressants, and monoamine oxidase inhibitors, can strengthen the anticholinergic effect of this class of drugs. Some liver metabolized antihistamines and liver drug enzyme inhibitors can cause adverse reactions when combined. Some antihistamines may mask some ototoxic drugs, such as the symptoms of toxicity of aminoglycoside antibiotics. Antihistamines can inhibit the skin test response of allergenic substances, so all antihistamine drugs should be stopped for several days before the skin test to avoid affecting the results of the skin test. The combination of this product with phenytoin may inhibit its liver metabolism and increase its toxicity. Care should be taken to monitor the concentration of phenytoin. can enhance the effects of amantadine, anticholinergics, haloperidol, phenothiazines and sympathomimetics. Simultaneous drinking or taking central nervous system inhibitors can enhance the efficacy of this product.

Chlorpheniramine poisoning

Chlorpheniramine (Pulmin) is one of the strongest antihistamines, with long-lasting effects, low dosage, and small side effects. Suitable for allergic diseases, drug allergic reactions, etc. Oral absorption is fast and complete, with a half-life of 12-15 hours. Adult dosage is 4 to 8 mg, and the incidence of adverse reactions is low.

Clinical manifestation

1. The most common adverse reactions are drowsiness, occasionally chest tightness, sore throat, fatigue, palpitations or bleeding tendency, and thick sputum. Overdose is manifested as difficulty urinating or painful urination, dizziness, dry mouth, nose, and throat, loss of appetite, nausea, epigastric discomfort, or stomach pain.

2. Children are prone to irritability, anxiety, difficulty falling asleep and nervousness.

3. There are reports of fixed drug rash, urticaria, angioedema, and even anaphylactic shock. Granulocytopenia, which is rare with general antiallergic drugs, can occur.

treatment

The main points of treatment for chlorpheniramine poisoning are:

Symptomatic treatment ^[3] .

Expert review of chlorpheniramine

Chlorpheniramine is a hydrocarbon amine antihistamine. It is characterized by strong antihistamine effect, small dosage and few adverse reactions. Suitable for children. For various allergic diseases, insect bites, drug allergic reactions, etc. In addition, drivers and machine operators should not use it during work. The antipruritic effect is better, and it is more commonly used clinically. In order to reduce drowsiness and dry mouth adverse reactions, it can be taken at night before going to bed for chronic allergic pain. Chlorpheniramine counteracts the allergic effects of histamine by antagonizing the H1 receptor. For skin and mucous membrane allergies, such as contact eyelid dermatitis, allergic conjunctivitis ^[2] .

Chlorpheniramine standard

[Identification] (1) Take about 10mg of this product, add 1ml of citric acid acetic anhydride test solution, and heat on a water bath, showing red and purple. (2) Take about 20mg of this product, add 1ml of dilute sulfuric acid, dropwise add potassium permanganate test solution, and the red color will disappear. (3) The infrared absorption spectrum of this product should be consistent with the control spectrum (spectrum set 61).

[Inspection] Take 0.1g of this product, add 10ml of water to dissolve it, and then measure it according to the method (Appendix VI H). Relevant substances are taken from this product, and the solvent [mobile phase A-acetonitrile (80:20)] is dissolved and diluted to a solution containing 1 mg per 1 ml as the test solution; a precise amount is taken and diluted with the above-mentioned solvents to make each A solution containing 3 g in 1 ml was used as a control solution. According to the high-performance liquid chromatography (Appendix VD) test, octadecylsilane bonded silica gel is used as the filler; mobile phase A is phosphate buffer solution (take 11.5 g of ammonium dihydrogen phosphate, add water to dissolve, and add phosphoric acid 1ml, diluted to 1000ml with water), mobile phase B is acetonitrile, gradient elution according to the following table; flow rate is 1.2ml per minute; detection wavelength is 225nm. The number of theoretical plates is not less than 4000 calculated based on the chlorpheniramine peak. Take 10 l of the control solution and inject it into the liquid chromatograph to adjust the detection sensitivity so that the peak height of the chlorpheniramine chromatographic peak is about 25% of the full scale. Then accurately measure 10 l each of the test solution and the control solution, and inject them into the liquid chromatograph respectively to record the chromatogram. If there is an impurity peak in the chromatogram of the test solution, the area of a single impurity peak should not be larger than the chlorpheniramine peak area (0.3%) in the control solution, except for the maleic acid peak. The sum of the peak areas of each impurity should not be greater than the control solution. Three times the area of the chlorpheniramine peak (0.9%). The chromatogram in the chromatogram of the test solution was less than 0.17 times the area of the chlorpheniramine peak in the control solution (0.05%).

Residual solvents: tetrahydrofuran, dioxane, pyridine, and toluene. Take this product, weigh it accurately, add dimethylformamide to dissolve and dilute it to make a solution containing about 0.2g per 1ml. , 1,4-dioxane, pyridine and toluene, precisely weighed, and quantitatively diluted with dimethylformamide to make 144 g of tetrahydrofuran per 1 ml, 76 g of 1,4-dioxane, 40 g of pyridine, toluene A solution of 178 g was used as a reference solution. Precisely measure 1 ml of each of the test solution and the photo solution, place them in a headspace bottle, and seal. According to the residual solvent measurement method (Appendix P second method), use 5% phenyl-95% methyl polysiloxane (or similar polarity) as the fixing solution; maintain the column temperature at 50 ° C for 15 minutes, The rate of 8 ° C per minute was raised to 120 ° C and maintained for 10 minutes; the inlet temperature was 200 ° C; the detector temperature was 250 ° C. The headspace flask equilibrium temperature was 90 ° C, the equilibrium time was 30 minutes, and the injection volume was 1.0 ml. Take the reference solution headspace sample, the number of theoretical plates calculated from the tetrahydrofuran peak is not less than 5000, and the resolution of each component peak should meet the requirements. Then take the test solution and the reference solution for headspace injection and record the chromatogram. The peak area calculated according to the external standard method should all meet the requirements. Take 25mg of this product for easy carbonization, and check it according to the law (Appendix O). Compared with the yellow colorimetric standard liquid, it must not be deeper. Loss on drying: Take this product and dry 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 0.15g of this product, accurately weigh, add 10ml of glacial acetic acid to dissolve, add 1 drop of crystal violet indicator solution, titrate with perchloric acid titration solution (0.1mol / L) until the solution is blue-green, and The results of the titration were corrected with a blank test. Each 1 ml of perchloric acid titration solution (0.1 mol / L) is equivalent to 19.54 mg of C ₁₆ H ₁₉ ClN ₂ · C ₄ H ₄ O ₄ .

[Category] Antihistamine.

[Storage] shading and sealed.

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