Method for treating exercise induced asthma

A method for preventing or treating exercise-induced asthma, cold-air induced asthma or pollution-induced asthma in a mammal at risk to suffer from or suffering from same by preferentially inhibiting the PDE 4 catalytic form that binds R-rolipram with a low affinity, which method comprises administering to a subject in need thereof an effective amount of a compound having an IC50 ratio of about 0.1 or greater calculated by dividing the IC50 for the PDE 4 catalytic form which binds R-rolipram with a high affinity divided by the IC50 for the catalytic form which binds R-rolipram with a low affinity.