Pharmacology Of Carbinoxamine

Indication	For symptomatic relief of seasonal and perennial allergic rhinitis and vasomotor rhinitis, as well as allergic conjunctivitis caused by foods and inhaled allergens. Also for the relief of allergic reactions to blood or plasma, and the symptomatic management of mild, uncomplicated allergic skin manifestations of urticaria and angioedema.
Pharmacodynamics	Carbinoxamine is a first generation antihistamine of the ethanolamine class. Ethanolamine antihistamines have significant antimuscarinic activity and produce marked sedation in most patients. In addition to the usual allergic symptoms, the drug also treats irritant cough and nausea, vomiting, and vertigo associated with motion sickness. It also is used commonly to treat drug-induced extrapyramidal symptoms as well as to treat mild cases of Parkinson's disease. Rather than preventing the release of histamine, as do cromolyn and nedocromil, carbinoxamine competes with free histamine for binding at HA-receptor sites. Carbinoxamine competitively antagonizes the effects of histamine on HA-receptors in the GI tract, uterus, large blood vessels, and bronchial muscle. Ethanolamine derivatives have greater anticholinergic activity than do other antihistamines, which probably accounts for the antidyskinetic action of carbinoxamine.
Mechanism of action	Carbinoxamine competes with free histamine for binding at HA-receptor sites. This antagonizes the effects of histamine on HA-receptors, leading to a reduction of the negative symptoms brought on by histamine HA-receptor binding. Carbinoxamine's anticholinergic action appears to be due to a central antimuscarinic effect, which also may be responsible for its antiemetic effects, although the exact mechanism is unknown.
Absorption	Not Available
Volume of distribution	Not Available
Protein binding	Not Available
Metabolism	Not Available
Route of elimination	Not Available
Half life	10 to 20 hours
Clearance	Not Available
Toxicity	Not Available