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Pyridamal 100: Full Drug Profile

Medically reviewed by Min Clinic Staff | Updated: January 2026

Pyridamal 100 - General Information

A histamine H1 antagonist used in allergic reactions, hay fever, rhinitis, urticaria, and asthma. It has also been used in veterinary applications. One of the most widely used of the classical antihistaminics, it generally causes less drowsiness and sedation than promethazine. [PubChem]

 

Pharmacology of Pyridamal 100

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. Pyridamal 100, 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.

 

Pyridamal 100 for patients

May cause excitability especially in children. Do not take this product unless directed by a physician, if you have a breathing problem such as emphysema or chronic bronchitis, or if you have glaucoma or difficulty in urination due to enlargement of the prostate gland. May cause drowsiness; alcohol, sedatives and tranquilizers may increase the drowsiness effect. Avoid alcoholic beverages, and do not take this product if you are taking sedatives or tranquilizers without first consulting your physician. Use caution when driving a motor vehicle or operating machinery.

 

Pyridamal 100 Interactions

Substrate of CYP2D6 (minor), 3A4 (major); Inhibits CYP2D6 (weak).

Increased toxicity (CNS depression): CNS depressants, MAO inhibitors, tricyclic antidepressants, phenothiazines.

CYP3A4 inhibitors: May increase the levels/effects of chlorpheniramine. Example inhibitors include azole antifungals, ciprofloxacin, clarithromycin, diclofenac, doxycycline, erythromycin, imatinib, isoniazid, nefazodone, nicardipine, propofol, protease inhibitors, quinidine, and verapamil.

 

Pyridamal 100 Contraindications

Hypersensitivity to chlorpheniramine maleate or any component of the formulation; narrow-angle glaucoma; bladder neck obstruction; symptomatic prostate hypertrophy; during acute asthmatic attacks; stenosing peptic ulcer; pyloroduodenal obstruction. Avoid use in premature and term newborns due to possible association with SIDS.

 

Additional information about Pyridamal 100

Pyridamal 100 Indication: For the treatment of rhinitis, urticaria, allergy, common cold, asthma and hay fever. Mechanism Of Action: Pyridamal 100 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. Drug Interactions: Donepezil Possible antagonism of actionGalantamine Possible antagonism of actionRivastigmine Possible antagonism of actionEthotoin The antihistamine increases the effect of hydantoinFosphenytoin The antihistamine increases the effect of hydantoinMephenytoin The antihistamine increases the effect of hydantoinPhenytoin The antihistamine increases the effect of hydantoin Food Interactions: Take with food.Avoid alcohol. Generic Name: Chlorpheniramine Synonyms: Chloropheniramine; Chlorophenylpyridamin; Chlorophenylpyridamine; Chloroprophenpyridamine; Chlorphenamine; Chlorpheniramine Maleate; Chlorprophenpyridamine; Clorfeniramina; Dexchlorpheniramine; Dexchlorpheniramine Maleate Drug Category: Anti-Allergic Agents; Antipruritics; Antihistamines Drug Type: Small Molecule; Approved Other Brand Names containing Chlorpheniramine: Aller-Chlor; Allergican; Allergisan; Antagonate; Chlo-Amine; Chlor-Trimeton; Chlor-Trimeton Allergy; Chlor-Trimeton Repetabs; Chlor-Tripolon; Chlorate; Chloropiril; Cloropiril; Efidac 24 Chlorpheniramine Maleate; Gen-Allerate; Haynon; Histadur; Kloromin; Mylaramine; Novo-Pheniram; Pediacare Allergy Formula; Phenetron; Piriton; Polaramine; Polaronil; Pyridamal 100; Telachlor; Teldrin; Absorption: Well absorbed in the gastrointestinal tract. Toxicity (Overdose): LD50 = 306 mg/kg in humans, mild reproductive toxin to women of childbearing age. Protein Binding: 72% Biotransformation: Primarily hepatic via Cytochrome P450 (CYP450) enzymes. Half Life: 21-27 hours Dosage Forms of Pyridamal 100: Tablet OralTablet, extended release OralSyrup Oral Chemical IUPAC Name: 3-(4-chlorophenyl)-N,N-dimethyl-3-pyridin-2-ylpropan-1-amine Chemical Formula: C16H19ClN2 Chlorpheniramine on Wikipedia: https://en.wikipedia.org/wiki/Chlorpheniramine Organisms Affected: Humans and other mammals