An inhaler (puffer or pump) is a medical device used for delivering medication into the body via the lungs. It is mainly used in the treatment of asthma and chronic obstructive pulmonary disease. Zanamivir, used to treat influenza, must be administered via inhaler.
To reduce deposition in the mouth and throat, and to reduce the need for precise synchronization of the start of inhalation with actuation of the device, MDIs are sometimes used with a complementary spacer or holding chamber device.