What Causes Poor Concentration And Weakness While On Seroflo?

Good Morning Doctor... My son is 7 years old and he is on taking Seroflo 50 since last one year due to recurring cough and wheezing issue. Initially, he was put on other inhalers of higher strengths and slowly doses are made mild as per health improvement. Over the past 2-3 years, we have observed degradation in my son s overall health (in terms of confidence, spirit to learn new things, immune, playing physical games outside, stamena issues, delay in learning, concentration, lack of concentration, low in energy so far and so forth)...please advise, can it be due to Inhaler which he is taking continuously since last 3-3.5 years.