Details

Zafirlukast is a leukotriene inhibitor. Leukotrienes are chemicals your body releases when you breathe in an allergen (such as pollen). These chemicals cause swelling in your lungs and tightening of the muscles around your airways, which can result in asthma symptoms. Zafirlukast is used for chronic treatment of asthma, and to prevent asthma attacks in adults and children as young as 5 years old. Do not give this medicine to a child younger than 5 years without a doctor's advice. You should not use this medicine if you are allergic to zafirlukast, or if you have liver disease (including cirrhosis). To make sure zafirlukast is safe for you, tell your doctor if you have a history of liver disease if you also take erythromycin or theophylline or if you also take a blood thinner.

Typical Uses

Zafirlukast is used to prevent asthma symptoms and to decrease the number of asthma attacks in people 5 and older. It helps make breathing easier by reducing swelling (inflammation) in the airways. Regular use of this medication can help control your asthma, improve your ability to exercise, and decrease the number of times you need to use your rescue inhaler. This medication works by blocking the activity of natural substances (leukotrienes) that may cause or worsen asthma. This medication does not work right away and is not used to treat sudden asthma attacks. This drug may also be used for hay fever and to prevent breathing problems while exercising.

Side Effects

Common zafirlukast side effects may include depressed mood, unusual thoughts or behaviour severe sinus pain or congestion numbness or tingly feeling in your arms or legs worsening or no improvement in your asthma symptoms liver problems-nausea, upper stomach pain, itching, tired feeling, loss of appetite, dark urine, clay-coloured stools, jaundice (yellowing of the skin or eyes) or high levels of certain white blood cells-skin rash, bruising, severe tingling, pain, muscle weakness, new or worsening cough, fever, trouble breathing.

Drug Interactions

• Zafirlukast+fentanyl- Zafirlukast may significantly increase the blood levels and effects of fentanyl. You may need a dose adjustment or more frequent monitoring by your doctor to safely use both medications. Talk to your doctor if you have any questions or concerns.
• Zafirlukast+leflunomide- Leflunomide may cause liver problems, and using it with other medications that can also affect the liver such as zafirlukast may increase that risk. Because leflunomide can stay in your blood for a prolonged period after the last dose, interactions with other drugs may occur for some time even after you have stopped taking it. You should avoid or limit the use of alcohol while being treated with these medications.
• Zafirlukast+mipomersen- Mipomersen may cause liver problems, and using it with other medications that can also affect the liver such as zafirlukast may increase that risk. You should avoid or limit the use of alcohol to no more than one drink per day while being treated with these medications.
• Zafirlukast+pimozide- Using pimozide together with zafirlukast is not recommended. Combining these medications may significantly increase the blood levels of pimozide. High blood levels of pimozide can increase the risk of an irregular heart rhythm that may be serious and potentially life-threatening, although it is a relatively rare side effect. You may be more susceptible if you have a heart condition called congenital long QT syndrome, other cardiac diseases, conduction abnormalities, or electrolyte disturbances.

Mechanism of action

Zafirlukast belongs to a group of medicines called leukotriene antagonists. Certain natural substances (leukotrienes) released in response to allergy cause swelling and narrowing of airways, thereby, causing difficulty in breathing. Zafirlukast blocks the action of leukotrienes, relaxes blocked airways, and eases breathing.

Pregnancy Category : B