クレマスチン

Soluble (hydrogen fumarate formulation)

4.05e-04 g/L

Breast Feeding; Lactation; Milk, Human; Antihistamines; Antipruritics

Pharmaceuticals

Despite widespread use, the first generation antihistamines such as clemastine have rarely been linked to liver test abnormalities or to clinically apparent liver injury. The reason for their safety may relate to low daily dose and limited duration of use.

Benchmark Dataset for the Liver Toxicity Knowledge Base (LTKB)

clemastine

Tavist®

Antihistamines

Not Applicable

no-DILI-concern

Clemastine

0.047

0.2

Tablets contain 1.34 mg clemastine fumarate (equivalent to 1 mg clemastine). Adults and children 12 years and older take 1 tablet every 12 hours; not more than 2 tablets in 24 hours.

Data used to generate the benchmarks include the following: Lowest Daily Dose (LDD): 2 mg/day, Lowest Therapeutic Dose (LTD): 0.025 mg/kg-day, and Screening Dose: 0.000008 mg/kg-day.

21-May-12

R - Respiratory system

D - Dermatologicals

QR - Respiratory system

QD - Dermatologicals

Clemastine is an antihistamine that also induces anticholinergic and sedative effects. Antihistamines competitively antagonize various physiological effects of histamine including increased capillary permeability and dilatation, the formation of edema, the "flare" and "itch" response, and gastrointestinal and respiratory smooth muscle constriction. Within the vascular tree, H1- receptor antagonists inhibit both the vasoconstrictor and vasodilator effects of histamine. Depending on the dose, H1- receptor antagonists can produce CNS stimulation or depression. Most antihistamines exhibit central and/or peripheral anticholinergic activity. Antihistamines act by competitively blocking H1- receptor sites. Antihistamines do not pharmacologically antagonize or chemically inactivate histamine, nor do they prevent the release of histamine.

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)