There were no differences in the incidence of adverse effects in the elderly compared with the other age groups. Patient acceptance of the device was high with a majority of patients preferring the disk system over their previous system regardless of age or gender. The proper use of the inhaler device could be taught easily to the majority of patients. However, a small number of patients demonstrated inadequate handling after 2 weeks of use suggesting the need for repeated verification of and teaching of inhaler technique.
Perhaps the most important barrier to effective delivery of inhaled medication is the ability of the patient to use the delivery systems adequately. Studies have demonstrated that a significant proportion of patients cannot properly coordinate the use of the oldest delivery system, the aerosol MDI.’ While this difficulty is evident in all age groups, elderly patients may represent a group at higher risk of inadequate technique. Therefore, the disk system described herein may have a particularly useful role in such patients, although we note that the elderly group in this study was more likely to have had difficulties in using the device.
Newer inhaled medication delivery systems and add-on spacer devices have been developed in the hope of creating a more “user friendly” system that can deliver an accurate amount of medication. Addon spacer devices have the additional advantage of decreasing local deposition of drug. Both add-on spacers and a multiple-dose dry powder delivery system (Turbuhaler) have been favorably evaluated as replacement devices for those with difficulties using MDIs itat on canadian neighbor pharmacy. The disk system has also been proposed as another alternative to the MDI.
Studies under well-controlled conditions with carefully screened patients with relatively small numbers have demonstrated the effectiveness of the disk system compared with the MDI and the Turbuhaler system.’ It appears that all presently available delivery systems are capable of delivering effective doses of ^-agonists. However, the artificial conditions of these studies and the relatively small numbers of subjects evaluated may not be representative of important clinical findings in the community once a device is available. Infrequent significant adverse events may be uncovered only in large studies.
In the present study, the most common, albeit infrequent, side effects were cough, tremor, and headache. An age-related increase in any of the common adverse events was not found. There were only 3 of 4,572 patients who experienced major adverse events that were considered to be drug related (allergic reaction in 1, increase in asthma symptoms in 1, and increase in blood pressure in 1). The rate of withdrawal due to deteriorating asthma was not inordinately high compared with other studies.
We recognize the limitations of this relatively simple open and unblinded trial. However, the latitude of such a design allows for the recruitment of large numbers of subjects and important evaluations of infrequent events and general acceptance or lack of acceptance of a new device and/or drug under realistic conditions. In addition, the large number of subjects recruited in this study forms an appropriate baseline for the expected incidence of adverse effects associated with inhaled ^-agonists, a feature that may be important when comparing presently available agents with newer, longer-acting preparations.
In summary, the Diskhaler system represents a reasonable alternative to other available inhaled airway medication delivery systems; it is easy to learn, well accepted, effective, and has a low incidence of adverse events. These conclusions apply to all age groups, although the elderly may require additional monitoring to ensure they are able to use the device properly.