MedlinePlus a600034 Routes of
administration Oral Legal status Withdrawn CAS ID 68844-77-9 | Pregnancy
category C (USA) ATC code R06AX11 (WHO) Molar mass 458.571 g/mol | |
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AHFS/Drugs.com Multum Consumer Information | ||
Astemizole (marketed under the brand name Hismanal, developmental code R43512) was a second-generation antihistamine drug that has a long duration of action. Astemizole was discovered by Janssen Pharmaceutica in 1977. It has been withdrawn from the market in most countries because of rare but potentially fatal side effects (QTc interval prolongation and related arrhythmias due to hERG channel blockade).
Contents
What does astemizole mean
Pharmacology
Astemizole is a histamine H1-receptor antagonist. It has anticholinergic and antipruritic effects.
Astemizole is rapidly absorbed from the gastrointestinal tract and competitively binds to histamine H1 receptor sites in the gastrointestinal tract, uterus, blood vessels, and bronchial muscle. This suppresses the formation of edema and pruritus (caused by histamine).
Despite some earlier reports that astemizole does not cross the blood–brain barrier, several studies have shown high permeability and high binding to protein folds associated with Alzheimer's.
Astemizole may also act on histamine H3 receptors, thereby producing adverse effects.
Astemizole does also act as FIASMA (functional inhibitor of acid sphingomyelinase).
Toxicity
Astemizole has an oral LD50 of approximately 2052 mg/kg (in mice).