How to Use a Metered-Dose Inhaler

To use a metered-dose inhaler, the person shakes the inhaler and removes the cap. The person exhales completely, then brings the inhaler close to or in the mouth and breathes in slowly while pressing the top of the inhaler. The person continues to inhale as a puff of medicine sprays out. The person then holds the breath and subsequently exhales again. Exhaling fully helps clear air from the lungs, so that more air can be inspired with the next inhalation. The more air is inhaled, the more of the medication can also be inhaled and thus reach the more distant, smaller airways.

See the Centers for Disease Control and Prevention: Self-Care for Asthma: Using Your Inhaler.