"There have been a few disgruntled phone calls after a patient learns that only 3 months worth of refills have been submitted to the pharmacy, instead of the standard 6-12 month supply.
Inhaled corticosteroids, when taken regularly as prescribed, generally take around 2 weeks to begin exerting their beneficial effects, but take around 6 weeks to reach maximal efficacy. So, after changing a patient's asthma controller medicine dose or regimen, I will wait at least 6 weeks before deciding if the new dose is working adequately. If it is working well, I will continue the dose for at least 3 months before attempting to decrease the dose. I always attempt to decrease, as long as the patient has done well for the past 3 months."
Asthma classification and treatment for each stage (click to enlarge the image).
The Doctor Will See You... Sooner Than You Thought? Why Asthma Patients Need Frequent Follow-Up. Achoo!- Adventures of an Allergist Mommy, 2010.