PHAR3817 Lecture Notes - Lecture 10: Drug Delivery, Nebulizer, Asthma
Document Summary
Breath actuated devices-> automatically fire when patient breaths in. Nebulizers-> don"t really use anymore- evidence shows drug delivery from nebulizer is same as from spacer pmdi"s. Press actuator and start inhaling at the same time (slow deep inspiration: hold breath. Exhale out: wait 1 min before using again. If you don"t shake you will get drug concentrate or empty solution. Studies support the need to gently exhale out either to functional residual capacity (frc) or residual volume (rv) before mdi actuation if you don"t breathe out fully then you don"t have the capacity to breathe fully in. Correct coordination leads to increased deposition in lung. Effect of fast inhalation (shaded bars) compared with slow inhalation (white bars) on (a) aerosol penetration into the lung and (b) fev. If you breathe out too quickly some particles will just be breathed back out- need to give time to settle. Flashing of propellant, cooling and aerosol property change.