Can using too much bronchodilator and corticosteroid be harmful?

Too much of anything: Using "too much" of almost anything can be harmful, especially medications. Bronchodilators can cause such effects as jitteryness and cardiac effects and if more than 2 times/week indicate the need for an inhaled steroid (ics). Ics's have a pretty wide safety dose range, but above recommended amounts may not add benefit. Oral steroids have multiple cumulative side effects. Use meds as prescribed.