About zafirlukast

Asthma is a common condition caused by inflammation in the airways. The inflammation irritates the muscles around the airways, and causes them to constrict. This causes your airways to narrow. It is then more difficult for air to get in and out of your lungs. This causes the typical symptoms of wheeze, chest tightness, and shortness of breath. The inflammation also causes the lining of your airways to make extra mucus which causes coughing.

Asthma symptoms flare up from time to time and there may be no apparent reason why. However, some people find that symptoms are made worse by triggers such as exercise, fumes, and pollen. These things cause your body to produce chemical substances called leukotrienes, which cause inflammation. Zafirlukast helps control the symptoms of asthma by blocking the effects of these leukotrienes.

Before taking zafirlukast

Some medicines are not suitable for people with certain conditions, and sometimes a medicine may only be used if extra care is taken. For these reasons, before you start taking zafirlukast it is important that your doctor or pharmacist knows:

• If you are pregnant, trying for a baby or breast-feeding.
• If you have liver or kidney problems.
• If you are taking or using any other medicines. This includes any medicines you are taking which are available to buy without a prescription, such as herbal and complementary medicines.
• If you have ever had an allergic reaction to a medicine.

How to take zafirlukast

• Before you start this treatment, read the manufacturer's printed information leaflet from inside your pack. The leaflet will give you more information about zafirlukast, and a full list of possible side-effects from taking it.
• Take zafirlukast twice a day, one tablet in the morning and one in the evening. Your dose will also be on the label of the pack.
• You should take the tablets 'on an empty stomach', which means you should take them about an hour before a meal, or wait until two hours afterwards. This is because your body absorbs less zafirlukast after a meal, which means the medicine is less effective.
• Take zafirlukast regularly every day, even if your asthma is well controlled. Try not to miss any of your doses, but if you do forget, take it as soon as you remember. If it is almost time to take your next dose, skip the missed dose and take your next dose when it is due. Do not take two doses together to make up for a forgotten dose.

Getting the most from your treatment

• Try to keep your regular appointments with your doctor. This is so your doctor can check on your progress. Also, your doctor may want you to have blood tests to check on the way your liver is working from time to time.
• Zafirlukast will not give you immediate relief if you are having an asthma attack. Your doctor will have prescribed a reliever inhaler for you to use if this happens. Make sure that you keep it with you all the time.
• If you find that your asthma symptoms are getting worse, or that you need to use the reliever inhaler more regularly than usual, contact your doctor or nurse for advice straightaway.
• Do not smoke. Smoking causes severe irritation and damage to the lungs. It will make your condition worse and will reduce the beneficial effects of your medication.
• If you buy any medicines, check with a pharmacist that they are safe for you to take. Some anti-inflammatory painkillers and aspirin can make asthma symptoms worse in some people.

Can zafirlukast cause problems?

Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. These usually improve as your body adjusts to the new medicine, but speak with your doctor or pharmacist if any of the following side-effects continue or become troublesome.

Important: if you get any of the following symptoms, you should let your doctor know straightaway:

• Continually feeling or being sick, jaundice (yellowing of your skin or the whites of your eyes), and generally feeling unwell. These can be signs of a liver problem and your doctor will want to check for this.
• Flu-like symptoms, numbness in your arms or legs, difficulties breathing, and a skin rash. These may be a sign of a rare but serious disorder called Churg-Strauss syndrome.

If you experience any other symptoms which you think may be due to this medicine, speak with your doctor or pharmacist.

How to store zafirlukast

• Keep all medicines out of the reach and sight of children.
• Store in a cool, dry place, away from direct heat and light.

Important information about all medicines