Leukotriene Modifiers #7

   Leukotrienes are chemicals that are responsible for airway inflammation in asthma and are part of what are called "slow-reacting substances of anaphylaxis". Leukotriene modifiers are most often used  in EIA ( Exercise -Induced Asthma ). In this case they are used prophylactically- that is to prevent attacks during exercise. They are also used in stable, mild, persistent asthma. This is also a prophylactic use. These drugs are not for acute attacks. In some cases they can be used as an alternative to inhaled corticosteroids but do not have the potency of low-dose steroids.This is why they are most often  used as an "add-on" to inhaled steroids so that the dose of steroids may be reduced. However, these drugs cannot be used as a substitute for  inhaled corticosteroids in moderate  or severe asthma without a loss of control.
   The most commonly used leukotriene modifier in the US today is montelukast (Singulair). In treating chronic asthma the usual adult dose is 10mg at bedtime. In treating EIA, the dose is usually 10mg at least 2 hours before exercise which should not be repeated within the next 24 hours. In pediatrics the dose varies depending on age:

• 12-23 months - 4mg (oral granules) at bedtime (granules can be mixed with a spoonful of applesauce, ice cream, carrots, or rice)
• 2-6 years  - 4mg (tablets) at bedtime (this can be either granules as above or chewable tablets)
• 6-14 years - 5 mg at bedtime
• over 15 years same dose as adults

   Allergy to the drug is the major contraindicated. Common side effects include headache, fatigue, dizziness, flu-like symptoms, rash, fever and itching. Drug interactions include phenytoin (Dilantin) and carbamazepine (Tegretol) which can reduce montelukast blood levels while drugs like gemfibozil (lopid) can increase blood levels.  Check with your  health care provider or pharmacist if you have any concerns or want additional information on this class of drugs