Drug Groups

approved

Description

First generation histamine H1 antagonist used in allergic rhinitis; asthma; and urticaria. It is a component of cough and cold medicines. It may cause drowsiness. [PubChem]

Indication

For the symptomatic relief of seasonal or perennial allergic rhinitis or nonallergic rhinitis; allergic conjunctivitis; and mild, uncomplicated allergic skin manifestations of urticaria and angioedema. Also used in combination with other agents for the symptomatic relief of symptoms associated with the common cold.

Pharmacology

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. Triprolidine, is a histamine H1 antagonist that 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. Triprolidine has anticholinergic and sedative effects.

Toxicity

Symptoms of overdose include drowsiness, weakness, inco-ordination, difficulty with micturition, respiratory depression, hypotension, agitation, irritability, convulsions, hypertension, palpitation and tachycardia.

Affected Organisms

Absorption

Rapidly absorbed in the intestinal tract.

Half Life

4 to 6 hours.

References

External Links