Is astemizole still available?

Hismanal Side Effects Center. Hismanal (astemizole) is an antihistamine used to treat allergies, hives (urticaria), and other allergic inflammatory conditions. The brand name Hismanal is discontinued, but generic versions may be available.

Is terfenadine an antihistamine?

Terfenadine is an antihistamine recently approved for use in the U.S. Terfenadine possesses a unique chemical structure when compared with other antihistamines. It is a selective inhibitor of H1-receptors with little or no anticholinergic, antiserotoninergic, or antiadrenergic effects.

Why was astemizole withdrawn from the market?

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 It was withdrawn from market by the manufacturer in 1999 due to the potential to cause arrhythmias at high doses, especially when when taken with CYP inhibitors or grapefruit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.

What is the relationship of fexofenadine and terfenadine?

Pharmacology. Terfenadine acts as a peripherally-selective antihistamine, or antagonist of the histamine H1 receptor. It is a prodrug, generally completely metabolized to the active form fexofenadine in the liver by the enzyme cytochrome P450 3A4.

What are the side effects of astemizole and terfenadine?

Toxic effects of terfenadine and astemizole have been reported in patients taking concomitant macrolides, especially clarithromycin [103–106 ], typically resulting in prolongation of the QT interval and cardiac dysrhythmias (torsade de pointes) [ 107 ].

When was terfenadine first marketed as an antihistamine?

Terfenadine, the first nonsedating antihistamine, was initially marketed in the United States in 1985 for the treatment of allergic rhinitis.

What are some of the names of antihistamines?

Terfenadine. Terfenadine is an antihistamine formerly used for the treatment of allergic conditions. It was brought to market by Hoechst Marion Roussel (now Sanofi-Aventis) and was marketed under various brand names, including Seldane in the United States, Triludan in the United Kingdom, and Teldane in Australia.

What kind of drugs are associated with terfenadine?

It is associated with either high doses of terfenadine or inhibition of its metabolism. Terfenadine depends solely on the 3A4 isoform of cytochrome P450, and inhibiting drugs include erythromycin, ketoconazole and even grapefruit juice.