people who have chronic obstructive pulmonary disease or some other lung conditions often take their medications using a device called a metered dose inhaler. an mdi is a handheld device that delivers a specific amount of medication in aerosol form rather than as a pill or capsule. the mdi consists of a pressurized canister inside a plastic case with a mouthpiece attached. with an mdi you press on the device while inhaling the copd medication directly into your lungs. its portability makes it easy to use anywhere anytime. mdis use a chemical propellant to push medication out of the inhaler. the two common chemical propellants are cfcs and hfcs. because cfcs cause damage to the ozone layer they are being being phased out and replaced by hfcs.
what is a metered dose inhaler?