Is your friend on multiple inhalers for his asthma, nubulized medication? does he have allergies as well? generally the more medication a patient is prescribed for asthma the more severe the condition., does he get acute attacks that put him in the hospital(they will usually prescribe oral prednisone for a few days once he is discharged from the ER) , or doctors office, or does he wheeze and cough with minimal respiratory distress?
A corticosteroid or cromolyn(inh NSAID type) will not help by itself in an acute attack, they are developed for maintenance therapy, he should have a short acting beta2 like albuterol.
an inhaler does not help when it is in the car,,got to keep it with you with patients with moderate severe asthma.