Metered dose inhalers and spacer devices.

Easy to carry, highly effective and extremely safe, allowing accurate, consistent dose delivery, metered dose inhalers are the inhalation devices doctors and patients choose most readily the world over. Clinical response, however, may be affected by the inhalation technique used and the precise formulation in the canisters. The purpose of this review is to consider metered dose inhalers, add on devices and training issues related to the proper coordination of drug delivery with inhalation, and to report on new technology and recent studies into non ozone depleting propellants, in compliance with the Montreal protocol.