allergetin

allergetin Uses, Dosage, Side Effects, Food Interaction and all others data.

Chlorpheniramine is an alkylamine antihistamine. It is one of the most potent H1 blocking agents and is generally effective in relatively low doses. Chlorpheniramine is not so prone to produce drowsiness, readily absorbed from the gastro-intestinal tract, metabolised in the liver and excreted usually mainly as metabolised in the urine.

In allergic reactions an allergen interacts with and cross-links surface IgE antibodies on mast cells and basophils. Once the mast cell-antibody-antigen complex is formed, a complex series of events occurs that eventually leads to cell-degranulation and the release of histamine (and other chemical mediators) from the mast cell or basophil. Once released, histamine can react with local or widespread tissues through histamine receptors. Histamine, acting on H1-receptors, produces pruritis, vasodilatation, hypotension, flushing, headache, tachycardia, and bronchoconstriction. Histamine also increases vascular permeability and potentiates pain. Chlorpheniramine, is a histamine H1 antagonist (or more correctly, an inverse histamine agonist) of the alkylamine class. It competes with histamine for the normal H1-receptor sites on effector cells of the gastrointestinal tract, blood vessels and respiratory tract. It provides effective, temporary relief of sneezing, watery and itchy eyes, and runny nose due to hay fever and other upper respiratory allergies.

Pseudoephedrine is structurally related to ephedrine but exerts a weaker effect on the sympathetic nervous system. Both drugs naturally occur in in ephedra plant which have a history of use in traditional Eastern medicine and were first researched in the west in 1889. The decongestant effect of pseudoephedrine was described in dogs in 1927.

Pseudoephedrine causes vasoconstriction which leads to a decongestant effect. It has a short duration of action unless formulated as an extended release product. Patients should be counselled regarding the risk of central nervous system stimulation.

Trade Name allergetin
Generic Chlorpheniramine + pseudoephedrine
Weight 2, 30mg
Type Syrup
Therapeutic Class
Manufacturer Kuwait Saudi Pharmaceutical Industries
Available Country Saudi Arabia
Last Updated: September 19, 2023 at 7:00 am
allergetin
allergetin

Uses

Indicated mainly in allergic conditions including urticaria, sensitivity reactions, angioneurotic oedema, seasonal hay fever, vasomotor rhinitis, cough, common cold, motion sickness.

Pseudoephedrine is an alpha and beta adrenergic agonist used to treat nasal and sinus congestion, as well as allergic rhinitis.

Pseudoephedrine is a sympathomimetic amine used for its decongestant activity.

allergetin is also used to associated treatment for these conditions: Allergic Contact Dermatitis, Allergic Reaction, Allergic Rhinitis (AR), Allergic cough, Allergies, Allergies caused by Serum, Allergy to House Dust, Allergy to vaccine, Angioneurotic Edema, Asthma, Bronchial Asthma, Bronchitis, Common Cold, Conjunctival congestion, Conjunctivitis, Conjunctivitis allergic, Cough, Cough caused by Common Cold, Coughing caused by Flu caused by Influenza, Drug Allergy, Eye allergy, Fever, Flu caused by Influenza, Food Allergy, Headache, Headache caused by Allergies, Itching of the nose, Itching of the throat, Migraine, Nasal Congestion, Nasal Congestion caused by Common Cold, Pollen Allergy, Productive cough, Pruritus, Rash, Rhinorrhoea, Seasonal Allergic Conjunctivitis, Sinus Congestion, Sinusitis, Sneezing, Transfusion Reactions, Upper Respiratory Tract Infection, Upper respiratory tract hypersensitivity reaction, site unspecified, Urticaria, Vasomotor Rhinitis, Acute Rhinitis, Allergic purpura, Conjunctival hyperemia, Dry cough, Excess mucus or phlegm, Itchy throat, Mild bacterial upper respiratory tract infections, Ocular hyperemia, Throat inflammation, Upper airway congestion, Upper respiratory symptoms, Watery eyes, Watery itchy eyes, Airway secretion clearance therapyAllergic Rhinitis (AR), Allergies, Common Cold, Common Cold Associated With Cough, Common Cold/Flu, Cough, Cough caused by Common Cold, Eye allergy, Fever, Flu caused by Influenza, Headache, Irritative cough, Nasal Allergies, Nasal Congestion, Nasal Congestion caused by Common Cold, Pain, Perennial Allergy, Priapism, Respiratory Allergy, Rhinorrhoea, Seasonal Allergic Rhinitis, Seasonal Allergies, Sinus Congestion, Sinusitis, Sneezing, Sore Throat, Symptoms of Acute Bronchitis Accompanied by Coughing, Throat irritation, Upper Respiratory Tract Infection, Upper respiratory tract congestion, Upper respiratory tract signs and symptoms, Dry cough, Minor aches and pains, Sinus pain, Watery itchy eyes, Airway secretion clearance therapy

How allergetin works

Chlorpheniramine binds to the histamine H1 receptor. This blocks the action of endogenous histamine, which subsequently leads to temporary relief of the negative symptoms brought on by histamine.

Pseudoephedrine acts mainly as an agonist of alpha adrenergic receptors and less strongly as an agonist of beta adrenergic receptors.[A10896] This agonism of adrenergic receptors produces vasoconstriction which is used as a decongestant and as a treatment of priapism. Pseudoephedrine is also an inhibitor of norepinephrine, dopamine, and serotonin transporters.

The sympathomimetic effects of pseudoephedrine include an increase in mean arterial pressure, heart rate, and chronotropic response of the right atria. Pseudoephedrine is also a partial agonist of the anococcygeal muscle. Pseudoephedrine also inhibits NF-kappa-B, NFAT, and AP-1.

Dosage

allergetin dosage

Adults: 4 mg 3-4 times daily.

Children:

  • Up to 1( one) year: 1 mg twice daily
  • 1-5 years: 1 mg 3-4 times daily
  • 6-12 years: 2 mg 3-4 times daily or as directed by the physician

Side Effects

Drowsiness, dizziness, headache, psychomotor impairment, urinary retention, dry mouth, blurred vision and gastro intestinal disturbances, paradoxical stimulation may rarely occur, especially in high dosage or in children.

Toxicity

Oral LD50 (rat): 306 mg/kg; Oral LD50 (mice): 130 mg/kg; Oral LD50 (guinea pig): 198 mg/kg [Registry of Toxic Effects of Chemical Substances. Ed. D. Sweet, US Dept. of Health & Human Services: Cincinatti, 2010.] Also a mild reproductive toxin to women of childbearing age.

The oral LD50 of pseudoephedrine is 2206mg/kg in rats and 726mg/kg in mice.

Patients experiencing an overdose of pseudoephedrine may present with giddiness, headache, nausea, vomiting, sweating, thirst, tachycardia, precordial pain, palpitations, difficulty urinating, muscle weakness, muscle tension, anxiety, restlessness, insomnia, toxic psychosis, cardiac arrhythmias, circulatory collapse, convulsions, coma, and respiratory failure. Treat overdose with symptomatic and supportive treatment including removal of unabsorbed drug.

Precaution

Chlorpheniramine may produce mild sedation and it is advised that patients under continuous treatment should avoid operating machinery. Not recommended during pregnancy & lactation.

Interaction

Alcohol, CNS depressants, anticholinergic drugs, MAOIs.

Volume of Distribution

The apparent volume of distribution of pseudoephedrin is 2.6-3.3L/kg.

Elimination Route

Well absorbed in the gastrointestinal tract.

A 240mg oral dose of pseudoephedrine reaches a Cmax of 246.3±10.5ng/mL fed and 272.5±13.4ng/mL fasted, with a Tmax of 6.60±1.38h fed and 11.87±0.72h fasted, with an AUC of 6862.0±334.1ng*h/mL fed and 7535.1±333.0ng*h/mL fasted.

Half Life

21-27 hours

The mean elimination half life of pseudoephedrine is 6.0h.

Clearance

A 60mg oral dose of pseudoephedrine has a clearance of 5.9±1.7mL/min/kg.

Elimination Route

55-75% of an oral dose is detected in the urine as unchanged pseudoephedrine.

Pregnancy & Breastfeeding use

Pregnancy Category B. Either animal-reproduction studies have not demonstrated a foetal risk but there are no controlled studies in pregnant women or animal-reproduction studies have shown an adverse effect (other than a decrease in fertility) that was not confirmed in controlled studies in women in the 1st trimester (and there is no evidence of a risk in later trimesters).

Contraindication

There is no definite contraindication to therapy. It should be used with caution in epilepsy, prostatic hypertrophy, glaucoma and hepatic disease. The ability to drive or operate machinery may be impaired.

Innovators Monograph

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*** Taking medicines without doctor's advice can cause long-term problems.
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