Verlukast

Verlukast is a leukotriene receptor antagonist (LTRA) that is used in the management of asthma and to relieve symptoms of allergic rhinitis. It works by blocking the action of leukotrienes, which are chemicals in the immune system that contribute to inflammation, bronchoconstriction, and mucus production in the airways.

Mechanism of Action

Verlukast functions by selectively antagonizing the cysteinyl leukotriene receptor CysLT1. Leukotrienes are inflammatory mediators derived from arachidonic acid through the lipoxygenase pathway. By blocking these receptors, Verlukast reduces bronchoconstriction, decreases mucus secretion, and mitigates airway inflammation, thereby improving respiratory function in patients with asthma.

Clinical Uses

Verlukast is primarily indicated for the prophylaxis and chronic treatment of asthma in adults and children. It is also used to alleviate symptoms of seasonal allergic rhinitis. Unlike some other asthma medications, Verlukast is not intended for the relief of acute asthma attacks.

Pharmacokinetics

Verlukast is administered orally and is well absorbed from the gastrointestinal tract. It undergoes extensive metabolism in the liver, primarily by the cytochrome P450 enzyme system. The drug is excreted mainly in the bile, with a small fraction eliminated in the urine. The half-life of Verlukast is approximately 3 to 6 hours, necessitating once or twice daily dosing.

Adverse Effects

Common side effects of Verlukast include headache, dizziness, and gastrointestinal disturbances such as nausea and diarrhea. Rarely, it may cause liver dysfunction, and patients should be monitored for signs of liver damage. Neuropsychiatric events, including agitation, depression, and suicidal thoughts, have been reported in some patients.

Contraindications and Precautions

Verlukast is contraindicated in patients with known hypersensitivity to the drug or any of its components. Caution is advised in patients with hepatic impairment due to the drug's metabolism in the liver. It is important to monitor liver function tests periodically during treatment.

Drug Interactions

Verlukast may interact with other medications metabolized by the cytochrome P450 system, such as warfarin, phenytoin, and theophylline. These interactions can alter the plasma concentrations of Verlukast or the co-administered drugs, necessitating dose adjustments.

Also see

• Leukotriene receptor antagonist
• Asthma management
• Allergic rhinitis
• Montelukast
• Zafirlukast