Drug Groups

approved; withdrawn

Description

Astemizole is a long-acting, non-sedating second generation antihistamine used in the treatment of allergy symptoms. It was withdrawn from market by the manufacturer in 1999 due to the potential to cause arrhythmias at high doses, especially when when taken with CYP inhibitors or grapefruit juice.

Indication

Astemizole was indicated for use in the relieving allergy symptoms, particularly rhinitis and conjunctivitis. It has been withdrawn from the market however due to concerns of arrhythmias.

Pharmacology

Astemizole is a second generation H₁-receptor antagonist. It does not significantly cross the blood brain barrier and therefore does not cause drowsiness or CNS depression at normal doses.

Toxicity

LD₅₀=2052mg/kg in mice

Affected Organisms

Biotransformation

Almost completely metabolized in the liver and primarily excreted in the feces.

Absorption

Rapidly absorbed from the gastrointestinal tract.

Half Life

1 day

Protein Binding

96.7%

References

External Links