Inhaled drug delivery: A practical guide to prescribing inhaler devices (6)

Another way to circumvent problems in coordinating actuation of the inhaler with early inspiration is to use a breath actuated device, most commonly a DPI, though more recently breath actuated pMDIs have become available. These newer breath actuated pMDIs deliver the plume of propellant and medication once the patient has overcome a resistance equivalent to an inspiratory flow of 30 L/min; there is at least a theoretical concern that this resistance might not be overcome during a severe asthma attack. As mentioned previously, many older DPIs require quite high inspiratory flows for optimal performance. Furthermore, the active ingredient is often mixed with a large amount of vehicle, usually lactose, that may induce cough and that many patients find unpleasant to inhale.

Category: Inhaled drug

Tags: Aerosols, Asthma, COPD, Drug therapy