Dexchlorpheniramine

Manufacturers, packers, and distributors of drug and drug products for human use are responsible for complying with the labeling, certification, and usage requirements as prescribed by the Federal Food, Drug, and Cosmetic Act, as amended (secs 201-902, 52 Stat. 1040 et seq., as amended; 21 U.S.C. 321-392).

SRP: At the time of review, criteria for land treatment or burial (sanitary landfill) disposal practices are subject to significant revision. Prior to implementing land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance on acceptable disposal practices.

Concurrent use /of ototoxic medications/ with antihistamines may mask the symptoms of ototoxicity such as tinnitus, dizziness, or vertigo. /Antihistamines/

Concurrent use of monoamine oxidase (MAO) inhibitors with antihistamines may prolong and intensify the anticholinergic and CNS depressant effects of antihistamines; concurrent use is not recommended. /Antihistamines/

Concurrent use /with alcohol or other CNS depression-producing medications/ may potentiate the CNS depressant effects of either these medications or antihistamines; also, concurrent use of maprotiline or tricyclic antidepressants may potentiate the anticholinergic effects of either antihistamines or these medications. /Antihistamines/

Anticholinergic effects may be potentiated when /anticholinergics or other medications with anticholinergic activity/ are used concurrently with antihistamines; patients should be advised to report occurrence of gastrointestinal problems promptly since paralytic ileus may occur with concurrent therapy. /Antihistamines/

R - Respiratory system

QR - Respiratory system

Dexchlorpheniramine is an antihistamine that antagonizes histamine H1 receptors.

Antihistamines used in the treatment of allergy act by competing with histamine for H1-receptor sites on effector cells. They thereby prevent, but do not reverse, responses mediated by histamine alone. Antihistamines antagonize, in varying degrees, most of the pharmacological effects of histamine, including urticaria and pruritus. Also, the anticholinergic actions of most antihistamines provide a drying effect on the nasal mucosa. /Antihistamines/

DEXCHLORPHENIRAMINE MALEATE ANTAGONIZES MANY OF CHARACTERISTIC EFFECTS OF HISTAMINE.

WHEN TESTED IN DOGS, ANTIHISTAMINIC POTENCY OF DEXTRO ISOMER WAS 100 TIMES GREATER THAN THAT OF LEVO ISOMER, & 2.5 TIMES GREATER THAN RACEMIC FORM. ON CIRCUS-MOVEMENT ATRIAL FLUTTER, LEVO FORM WAS 1.4 & 2.3 TIMES THAT OF RACEMIC & DEXTRO CMPD.

H1 antagonists inhibit most responses of smooth muscle to histamine. Antagonism of the constrictor action of histamine on respiratory smooth muscle is easily shown in vivo and in vitro. /Histamine Antagonists: H1 Antagonists/

For more Mechanism of Action (Complete) data for DEXCHLORPHENIRAMINE (7 total), please visit the HSDB record page.

MAIN SITE OF METABOLIC TRANSFORMATION IS LIVER. /ANTIHISTAMINES/

Primarily hepatic via Cytochrome P450 (CYP450) enzymes. Half Life: 21-27 hours

Agents, usually topical, that relieve itching (pruritus).

Drugs that selectively bind to but do not activate histamine H1 receptors, thereby blocking the actions of endogenous histamine. Included here are the classical antihistaminics that antagonize or prevent the action of histamine mainly in immediate hypersensitivity. They act in the bronchi, capillaries, and some other smooth muscles, and are used to prevent or allay motion sickness, seasonal rhinitis, and allergic dermatitis and to induce somnolence. The effects of blocking central nervous system H1 receptors are not as well understood.

Agents that are used to treat allergic reactions. Most of these drugs act by preventing the release of inflammatory mediators or inhibiting the actions of released mediators on their target cells. (From AMA Drug Evaluations Annual, 1994, p475)