A spacer is a chamber that can be attached to a metered-dose inhaler (MDI). The spacer may have a one-way valve that holds the medicine in the chamber before it is inhaled. This way you can inhale the medicine in one or many breaths, depending on your ability. A spacer:

• May help prevent getting a yeast infection in your mouth. And using one can prevent your voice from sounding hoarse.
• Delivers more medicine straight to your airways. This is true even if you have trouble using your inhaler.
• Reduces the amount of medicine you swallow. This means you are less likely to have side effects.

It is especially important to use a spacer with an inhaler that contains corticosteroids. Spacers also may be used by children who have trouble using a metered-dose inhaler correctly. Don't use a dry powder inhaler (DPI) with a spacer.