Treatment

Devices Used for Administering Inhaled Drugs

Most asthma drugs are inhaled using various forms of inhalers or nebulizers. Inhaled drugs must be used regularly as prescribed and the patient carefully trained in their use in order for them to be effective and safe. Studies suggest that many children fail to use the devices properly, although newer devices are easier to use than others. The basic devices are the metered-dose inhaler (MDI), breath-actuated inhalers, dry powder inhalers, and nebulizers.

MDIs have used chlorofluorocarbons (CFCs) as their propellants. CFCs are damaging to the environment. Over time CFCs are being replaced with other propellants (e.g., hydrofluoroalkane) that are equally effective to CFCs, are environmentally safe, and do not chill the device as CFCs do. Devices that don't use propellants at all are also now available.

Metered-Dose Inhaler. The standard device for administering any asthma medication has been the metered-dose inhaler (MDI). This device, particularly when used with a holding chamber, allows precise doses to be delivered directly to the lungs. MDI-delivered drugs must be used regularly as prescribed and the patient carefully trained in their use in order for them to be effective and safe. Some patients hold the MDI too close to their mouths, or even inside them. Others may exhale too forcefully before inhalation. The holding chamber, or spacer, allows the patient additional time to inhale the medication and so improves delivery. They vary, however, in their ability to deliver medication. For example, in one study the AiroChamber-Plus was more effective than the EasiVent in delivering an inhaled steroid. It should be noted that often MDIs continue to deliver propellant after the drug has been used up. Patients should track their medicine and throw the device away when the last dose has been administered. Nebulizers (not MDIs) are typically used in very small children, both at home and in the emergency room. However, recent studies suggest that with the use of a face mask and a spacer, the MDI is effective even for infants in the emergency room and may prove to be useable at home.