Efficacy and tolerability of beclomethasone dipropionate delivered by a novel multidose dry powder inhaler (Clickhaler®) versus a metered-dose inhaler in children with asthma

The use of inhaled corticosteroids in pediatric asthma: update

Despite the availability of several formulations of inhaled corticosteroids (ICS) and delivery devices for treatment of childhood asthma and despite the development of evidence-based guidelines, childhood asthma control remains suboptimal. Improving uptake of asthma management plans, both by families and practitioners, is needed. Adherence to daily ICS therapy is a key determinant of asthma control and this mandates that asthma education follow a repetitive pattern and involve literal explanation and physical demonstration of the optimal use of inhaler devices. The potential adverse effects of ICS need to be weighed against the benefit of these drugs to control persistent asthma especially that its safety profile is markedly better than oral glucocorticoids. This article reviews the key mechanisms of inhaled corticosteroid action; recommendations on dosage and therapeutic regimens; potential optimization of effectiveness by addressing inhaler technique and adherence to therapy; and updated knowledge on the real magnitude of adverse events.

Efficacy and tolerability of budesonide Clickhaler and Turbuhaler in adult asthma

New dry powder inhalers should be clinically comparable with established devices to ensure the continuity of effective therapy for asthma patients. This randomized, open, parallel group study compared the clinical efficacy and tolerability of budesonide delivered via Clickhaler or Turbuhaler dry powder inhalers in adults with mild to moderate stable asthma. Following a 4-week stabilizing period using budesonide Turbuhaler adults aged 18 years or older, who had been treated with inhaled corticosteroids for at least the previous 12 weeks, were randomized to receive budesonide twice daily (<or=1600 microg/day) via either Clickhaler (n=110) or Turbuhaler (n=112) for 12 weeks. Morning peak expiratory flow (PEF), evening PEF, asthma symptoms, and use of inhaled short-acting beta2-agonist were recorded daily by the patients on diary cards. Lung function and tolerability data were recorded at clinic visits following 4, 8, and 12 weeks' treatment. Efficacy was measured primarily by mean change from the run-in baseline in weekly morning PEF. Of the 222 patients randomized to treatment, 167 completed the study according to the protocol. Repeated-measures analysis of covariance indicated that the devices were clinically equivalent; a treatment difference of--2.3 L/min separated the group mean changes in weekly morning PEF (95% confidence interval--7.9 to 3.3). Secondary analyses also supported clinical comparability. This study demonstrates the comparable clinical efficacy and tolerability of budesonide Clickhaler and Turbuhaler devices in adult patients with stable asthma.

Propellant-driven metered-dose inhalers for pulmonary drug delivery

The current market for pulmonary drug delivery is at a bottleneck. The therapeutic advantages of inhalation aerosols, and the potential for the lungs as a route for systemically acting drugs, vaccines and gene therapeutic agents, have resulted in a rapid growth of the industry. Alongside this, the environment of inhaler design and formulation has changed markedly in recent years. Environmental concerns over propellants, the commercial success of dry powder inhalers, and the apparent lack of advancement of propellant-driven metered-dose inhalers (pMDIs) has led to a less clear future for these devices. This review critically assesses these pressures and also potential opportunities for the pMDI. It is proposed that the future role of pMDIs will be determined by several important forces that can be classified under 'technology development' or 'market climate' categories. Technology development forces will be strengthened by the ability of the industry to have a systematic understanding of mechanisms of spray formation, perform subsequent and continued device and formulation advances, and a focus on all patient groups: particularly paediatric and geriatric populations. The ability to succeed in these areas will be largely determined by the willingness to invest in fundamental research of pMDI technologies.

The inhalers of the future? A review of dry powder devices on the market today

International agreements to ban the use of environmentally damaging chlorofluorocarbons (CFCs) have signalled an end to the traditional CFC-propelled pressurised metered dose inhaler (pMDI) which has long been the mainstay of topical asthma therapy. The need for acceptable and cost-effective replacement inhalers, combined with opportunities to develop generic formulations of patent-expired drugs, has fueled a lively response from the pharmaceutical industry. Improvements in pMDI design and reformulation with propellants such as hydrofluoroalkanes may offer significant advantages over CFC-pMDIs and prolong the widespread use of pressurised drug delivery systems for many years to come. In the longer term, however, another likely candidate for success in providing economical, efficient and acceptable inhaled therapies is the breath-actuated, multiple-dose dry powder inhaler (DPI). This review concentrates on the multiple-dose DPIs available within Europe today.

Majority of children aged 3 years and above can reliably inhale through the Clickhaler

Guidelines suggest that pressurized metered dose inhalers (pMDI) plus spacers are the delivery system of choice for children. However, they are bulky, which makes them inconvenient. It was suggested that the smaller dry-powder inhalers (DPIs) may be suitable for delivering short-acting bronchodilators to preschool children. This study considered whether preschool children could reliably generate sufficient inspiratory flows to use the Clickhaler DPI. Twenty-seven asthmatic and 34 nonasthmatic children, aged 2-5 years, were recruited. Following training, they were asked to inhale four times through a Clickhaler flow monitoring system, twice "steadily" and twice "forcefully." Inspiratory flow data were collected during each inhalation. Of the 3-, 4-, and 5-year-old asthmatics, 62.5, 100, and 100%, respectively, could reliably differentiate between inhaling and exhaling through the DPI. For nonasthmatics, the figures were 66, 60, and 88%, respectively. All but one of the children who understood the instructions generated a PIF of greater than 15 l/min (range, 13.9-88.3 l/min and 21.2-84.5 l/min in asthmatic and nonasthmatic children, respectively). These data indicate that the majority of children aged 3 years and above could reliably inhale rather than exhale through a dry-powder inhaler, and that they generate inspiratory flows sufficient to use the Clickhaler effectively. The results indicate that the device could be a suitable delivery system for beta(2)-agonists in preschool children.

Inspiratory flow rate through a dry powder inhaler (Clickhaler) in children with asthma

Dry powder inhalers (DPIs) are increasingly being used to deliver drugs for the treatment of asthma. Both the aerosolization and delivery of the drug from a DPI to the lung are dependent on an adequate inspiratory effort from the patient, and it is well-known that the air flow achieved early in the inspiratory profile is important in determining particle size distribution from the inhaler. The present study assessed the peak inspiratory flow (PIF) generated through the Clickhaler DPI, and the early inspiratory flow at 150 mL of inspired volume (IF(150)), in asthmatic children. These measurements were made in a well-controlled setting, and two attempts were recorded to establish maximum achievement. Results were obtained from 57 children aged 6-17 years, showing a (mean +/- SD) best PIF of 60.5 +/- 18.7 L/min (range, 26.8-97.0). The mean PIF overall was 54.2 +/- 20.8 L/min (7.9-97.0). For children aged 6-8 years, the mean best PIF was 46.5 +/- 14.6 L/min (26.8-71.1); for those aged 9 years or more, it was >65 L/min (30.3-97.0). PIF values were unrelated to % predicted FEV(1) measurements. Best IF(150) (mean +/- SD) was 42.9 +/- 13.6 L/min (23.1-66.6) in children aged 6-8 years, and >55 L/min (28.0-86.4) for the older children, showing that high flow rates were achieved early in the inspiratory profile. These data indicate that children with stable asthma can generate adequate inspiratory flow rates to operate the Clickhaler effectively.