Bronchodilator drugs are accepted if they are taken by way of an inhaler and the athlete is registered as asthmatic. To my knowledge it is not against IOC guidelines to take such drugs in this way prior to competition as there are no known performance enhancing effects.

There are different forms of asthma though; the drugs help the physiological symptoms and by way of placebo for the psychological causes of the symptoms. It might be worth asking him if he needs the inhaler during training to ascertain if the cause is purely physiological.