If someone has severe enough asthma for it to be life-threatening, they shouldn't be using OTC inhalers anyways. It's a lousy way to control moderate or severe asthma.
The product would not be used for a moderate or severe problem. Asthma can kill. But the inhaler seems to be enough to take care of an occasional light touch of asthma. By all means, if the problem is severe get to the doctor.