Welcome to HCM
Your brother is Asthamatic and may be he has some component like Pulmonary obstructive disease but as you said he is not smoker.
He should be investigated properly to know allergic etiology and reversibility of bronchospasm
by PFT ( Pulmonary function Test) serum IGE level to know allergy, he can also get allergy test in vitro and can avoid those allergens.
is cornerstone in treatment of asthma,which will help him if find difficult may use a Nebulizer to get proper deposition of drug in lungs.
or oral corticosteroid may also help him
There are other preventive medicines like montelucast.,once his symptoms are controlled he should practice pranayam and yoga. At least deep breathing exercises.
A chronic lung disease
in advance stages can cause right heart failure
It is the chest Physician/Pulmonologist who will decide inhalers are Ok or he needs other drugs also.