Cromolyn sodium inhibits the degranulation of mast cells and therefore the release of histamines and leukotrienes. The exact mechanism is not known. Cromolyn sodium has a short duration of action. So it needs to be applied at least 4 times a day.
In hay fever periods the drug can best be used as prophylaxis. But since the maximal prophylactic effect is reached after several weeks dosing should start early. The drug is generally well tolerated. Cromolyn sodium is drug of choice for chronic allergic rhinitis in children.
Which one of the following substances works to directly reverse bronchoconstriction and hence is the treatment of choice in severe, allergic respiratory distress?
Extra info: Epinephrine can be lifesaving in anaphylaxis. Once the disease process is well underway, the other drugs (A & B) are of little value. You must know this! You will not have time to look it up in an emergency situation!
Which of the following substances could prevent the ragweed allergen from reaching the sensitized mast cell?
Extra info: This is blocking antibody. All other drugs act after the antigen has bound to the receptor.