Zileuton:
         a 5-lipoxygenase inhibitor

1. Zileuton blocks Leukotriene synthesis.
2. Leukotrienes are not able to amplify inflammatory reaction.

Montelukast:
          a cysLT receptor antagonist

1. Montelukast blocks leukotriene receptors.
2. Intracellular signaling from these receptors is reduced.
3. The ability to stimulate an inflammatory response is reduced.

Aspirin Sensitivity

In some patients, moderate to high doses of aspirin may accentuate difficulty with breathing durng an asthma attack and accentuate immune responses.

1. Aspirin decreases prostaglandin production.
2. Arachidonic acid is funneled into leukotriene production.
3. The increased production of leukotrienes causes bonchioconstriction and stimulates the immune response.