Introduction
Zukast Tablet 20 mg is an oral leukotriene receptor antagonist (LTRA) for the maintenance treatment of asthma, often used in conjunction with an inhaled steroid and/or long-acting bronchodilator. It is available as a tablet and is usually dosed twice daily. Another leukotriene receptor antagonist is montelukast (Singulair), which is usually taken just once daily.
Zukast Tablet 20 mg blocks the action of the cysteinyl leukotrienes on the CysLT1 receptors, thus reducing constriction of the airways, build-up of mucus in the lungs and inflammation of the breathing passages.
Uses
Zukast Tablet 20 mg is a leukotriene receptor antagonist used for prophylaxis and chronic treatment of asthma.
For the prophylaxis and chronic treatment of asthma.
Associated Conditions
Pharmacodynamics
Zukast Tablet 20 mg is a synthetic, selective peptide leukotriene receptor antagonist (LTRA) indicated for the prophylaxis and chronic treatment of asthma. Patients with asthma were found in one study to be 25-100 times more sensitive to the bronchoconstricting activity of inhaled LTD4 than nonasthmatic subjects. In vitro studies demonstrated that zafirlukast antagonized the contractile activity of three leukotrienes (LTC4, LTD4 and LTE4) in conducting airway smooth muscle from laboratory animals and humans. Zukast Tablet 20 mg prevented intradermal LTD4-induced increases in cutaneous vascular permeability and inhibited inhaled LTD4-induced influx of eosinophils into animal lungs.
Mechanism of Action
Zukast Tablet 20 mg is a selective and competitive receptor antagonist of leukotriene D4 and E4 (LTD4 and LTE4), components of slow-reacting substance of anaphylaxis (SRSA). Cysteinyl leukotriene production and receptor occupation have been correlated with the pathophysiology of asthma, including airway edema, smooth muscle constriction, and altered cellular activity associated with the inflammatory process, which contribute to the signs and symptoms of asthma.
Absorption
Rapidly absorbed following oral administration, reduced following a high-fat or high-protein meal.
Volume of Distribution
- 70 L
Protein Binding
99%
Route of Elimination
The most common metabolic products are hydroxylated metabolites which are excreted in the feces.
Half Life
10 hours
Clearance
- apparent oral CL=20 L/h
- 11.4 L/h [7-11 yrs]
- 9.2 L/h [5-6 yrs]
Toxicity
Side effects include rash and upset stomach.
Food Interactions
- Take on an empty stomach. Take at least 1 hour before or 2 hours after meals.
Dosage
Children under 7 years of age: There is no clinical experience of the use of Zukast Tablet 20 mg in children under 7 years of age until safety information is available.
Children over 7 years through 11 years of age: The recommended dose of Zukast Tablet 20 mg in this age group is 10 mg twice daily.
Adult and children aged 12 years and over: The dosage is one 20 mg tablet twice daily. This dosage should not be exceeded. Higher doses may be associated with elevations of one or more liver enzymes consistent with hepatotoxicity. As food may reduce the bioavailability of Zukast Tablet 20 mg, Zukast Tablet 20 mg should not be taken with meals
Elderly: The clearance of Zukast Tablet 20 mg is significantly reduced in elderly patients (over 65 years old), and Cmax and AUC are approximately double than those of younger adults. However, accumulation of Zukast Tablet 20 mg is not greater than that seen in multiple dose trials conducted in adult subjects with asthma and the consequences of the altered kinetic in the elderly are unknown. Clinical experience with Zukast Tablet 20 mg in the elderly (over 65 years) is limited and caution is recommended until further information is available.
Renal impairment: No dosage adjustment is necessary in patients with mild renal impairment.
