Histadyl
Histadyl Uses, Dosage, Side Effects, Food Interaction and all others data.
Histadyl is an alkylamine antihistamine. It is one of the most potent H1 blocking agents and is generally effective in relatively low doses. Histadyl 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. Histadyl, 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.
| Trade Name | Histadyl |
| Availability | Rx and/or OTC |
| Generic | Chlorpheniramine |
| Chlorpheniramine Other Names | Chlorophenylpyridamine, Chlorphenamin, Chlorphenamine, Chlorphenaminum, Chlorpheniramine, Chlorpheniramine polistirex, Chlorpheniraminum, Clorfenamina, Clorfeniramina |
| Related Drugs | prednisone, cetirizine, loratadine, fluticasone nasal, promethazine, diphenhydramine, triamcinolone, Benadryl, Zyrtec, Promethazine DM |
| Weight | 4mg, 2mg/5ml, |
| Type | Tablet, Syrup |
| Formula | C16H19ClN2 |
| Weight | Average: 274.788 Monoisotopic: 274.123676325 |
| Protein binding | 72% |
| Groups | Approved |
| Therapeutic Class | Sedating Anti-histamine |
| Manufacturer | Rephco Pharmaceuticals Ltd |
| Available Country | Bangladesh, |
| Last Updated: | September 19, 2023 at 7:00 am |
Uses
Indicated mainly in allergic conditions including urticaria, sensitivity reactions, angioneurotic oedema, seasonal hay fever, vasomotor rhinitis, cough, common cold, motion sickness.
Histadyl 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 therapy
How Histadyl works
Histadyl 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.
Dosage
Histadyl 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.
Precaution
Histadyl 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.
Food Interaction
- Avoid alcohol.
- Take with food.
[Moderate] GENERALLY AVOID: Alcohol may potentiate some of the pharmacologic effects of CNS-active agents.
Use in combination may result in additive central nervous system depression and
MANAGEMENT: Patients receiving CNS-active agents should be warned of this interaction and advised to avoid or limit consumption of alcohol.
Ambulatory patients should be counseled to avoid hazardous activities requiring complete mental alertness and motor coordination until they know how these agents affect them, and to notify their physician if they experience excessive or prolonged CNS effects that interfere with their normal activities.
Histadyl Drug Interaction
Moderate: diphenhydramine, diphenhydramine, cetirizine, cetirizineUnknown: aspirin, aspirin, omega-3 polyunsaturated fatty acids, omega-3 polyunsaturated fatty acids, fluticasone nasal, fluticasone nasal, acetaminophen, acetaminophen, acetaminophen, acetaminophen, cyanocobalamin, cyanocobalamin, ascorbic acid, ascorbic acid, cholecalciferol, cholecalciferol
Histadyl Disease Interaction
Moderate: anticholinergic effects, asthma/COPD, cardiovascular, renal/liver disease
Elimination Route
Well absorbed in the gastrointestinal tract.
Half Life
21-27 hours
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
You find simplified version here Histadyl
Histadyl contains Chlorpheniramine see full prescribing information from innovator Histadyl Monograph, Histadyl MSDS, Histadyl FDA label
FAQ
What is Histadyl used for?
Histadyl is an antihistamine used to relieve symptoms of allergy, hay fever, and the common cold. These symptoms include rash, watery eyes, itchy eyes/nose/throat/skin, cough, runny nose, and sneezing.
How safe is Histadyl?
Histadyl is approved by the U.S. Food and Drug Administration and is safe and effective when used according to the Drug Facts label directions.
How does Histadyl work?
Histadyl works by blocking the action of histamine, a substance in the body that causes allergic symptoms.
What are the common side effects of Histadyl?
Common side effects include feeling sick (nausea), sleepy or dizzy. You may also have difficulty concentrating, a dry mouth, headaches or blurred vision.
Is Histadyl safe during pregnancy?
To conclude first generation antihistamines such as chlorpheniramine, hydroxyzine, and dexchlorpheniramine are the safest among antihistamines to be used in pregnancy.
Is Histadyl safe during breastfeeding?
Small occasional doses of Histadyl are acceptable during breastfeeding. Larger doses or more prolonged use might cause effects in the infant or decrease the milk supply, particularly in combination with a sympathomimetic such as pseudoephedrine or before lactation is well established.
Can I drink alcohol with Histadyl?
Do not drink alcohol while you're taking Histadyl. Alcohol may make you feel sick or more sleepy.
Can I drive after taking Histadyl?
After taking Histadyl you may feel very tired and sleepy. Do not drive, ride a bike or operate machinery or tools if this happens to you.
When should be taken of Histadyl?
The regular capsules of Histadyl are usually taken every 4 to 6 hours as needed. The extended-release tablets and capsules are usually taken twice a day in the morning and evening as needed.
Can I take Histadyl on an empty stomach?
Histadyl may be taken with food or milk if stomach upset occurs.
How long does Histadyl take to work?
Histadyl usually takes 30 minutes to 1 hour to work.
How long does Histadyl stay in my system?
Histadyl has a serum half-life of approximately 20 hours in adults, and elimination from the body is primarily by metabolism to monodesmethyl and didesmethyl compounds.
How long can Histadyl be taken?
You can buy many different Histadyls and forms of antihistamines without a prescription. Some work for only 4 to 6 hours, while others last for 12 to 24 hours. Some are combined with a decongestant, a drug that dries up your nasal passages.
Who should not take Histadyl?
Always ask a doctor before giving a cough or cold medicine to a child. Death can occur from the misuse of cough and cold medicines in very young children. You should not use Histadyl if you have narrow-angle glaucoma, a blockage in your stomach or intestines, an enlarged prostate, if you are unable to urinate, or if you are having an asthma attack.
What happens if I miss a dose?
Since this medicine is taken when needed, you may not be on a dosing schedule. If you are taking the medication regularly, take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.
What happens if I overdose?
Seek emergency medical attention. Overdose symptoms may include severe forms of some of the side effects listed in this medication guide.
Does Histadyl affect liver?
Despite widespread use, the first generation antihistamines such as brompheniramine and Histadyl have rarely been linked to liver test abnormalities or to clinically apparent liver injury.
Can Histadyl cause kidney problems?
Histadyl do not cause kidney problems.
Will Histadyl affect my fertility?
Studies have not been done to see if Histadyl could affect male fertility or increase the chance of birth defects. In general, exposures that fathers or sperm donors have are unlikely to increase the risks to a pregnancy.
Can I stop taking Histadyl?
If you suddenly stop using this medication, you may have withdrawal symptoms (such as restlessness, watering eyes, runny nose, nausea, sweating, muscle aches). To help prevent withdrawal, your doctor may lower your dose slowly.
