Astemizole when given orally has a slow onset of action (2-4hrs) and a very long duration of action of about 2-5 days. It is highly plasma protein bound ( 97%). It has plasma halflife of 20 hrs. It has an active metabolite which has a half life of 12-19 days. The drug is mainly excreted through faeces.

Astemizole is a non-sedative drug. It antagonises the H1 receptors by competitive inhibition. It is used in the treatment of histamine induced broncho-constriction, intestinal smooth muscle contraction, triple response, type-1 hypersensitivity reaction, urticaria, itching and angioedema.

Routes of Administration and Dosage

For oral dosage forms (tablets or liquid) in Adults: 10 milligrams (mg) once a day, in Children younger than 6 years of age: 0.2 mg per kilogram (kg) of body weight once a day, in Children 6 to 12 years of age: 5 mg once a day.

Contra Indications

The drug is contraindicated in hypersensitivity, pregnancy, lactation, during concomitant use of Macrolide antibiotic, itraconazole and ketoconazole.

Precautions

Precaution has to be taken in urinary tract problems, prostatic hypertrophy and in Glaucoma. In hepatic disease the level of astemizole is increased thus increasing its toxicity. Use of astemizole in those with hypokalemia may cause arrhythmias.

Interactions

Use of Quinine, Azithromycin, Clarithromycin, Erythromycin, Itraconazole and Ketoconazole with astemizole may cause cardiac problems, such as arrhythmias ; hence these drugs should not be used together.

Brand Names

Acemiz(Lupin), Acipax(Wyeth Lederle), Afdizol(AFD), Alerzole(Themis Pharma), Alestol(Indoco), Astelong(Torrent), Astem(Medley), Camstem-10(Camlin), Hismanal(Ethnor), Histalong(Stangen), Histeese(Micro Labs), Minastem(Glenmark), Perione(Merind), Stemiz(Cadila Healthcare).

Pharmacokinetics | Indications | Routes of Administration and Dosage | Contra Indications | Precautions | Interactions | Brand Names

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