Respimat (a new soft mist inhaler) delivering fenoterol plus ipratropium bromide provides equivalent bronchodilation at half the cumulative dose compared with a conventional metered dose inhaler in asthmatic patients

Novel drug delivery systems and significance in respiratory diseases

Pulmonary drug delivery offers targeted therapy for the treatment of respiratory diseases such as asthma, lung cancer, and chronic obstructive pulmonary diseases. However, this route poses challenges like deposition mechanism, drug instability, and rapid clearance mechanism. Other factors like the type of inhaler device, patient compatibility, consistent delivery by device, and inhaler technique also affect the performance of pulmonary delivery systems. Thus, to overcome these issues, pulmonary delivery systems utilizing particle-based approaches (nano/microparticles) have emerged in the last two decades. This chapter provides insight into various mechanisms of pulmonary drug administration, the ideal requirements of a pulmonary system, and the general devices used for pulmonary delivery. An overview of new pulmonary delivery systems and their relevance in the treatment of respiratory diseases is provided. In the end, novel pulmonary technologies that have been patented and cleared clinical trials have been highlighted along with the advances in the inhaler device.

Inhalation device options for the management of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is characterized by chronic respiratory symptoms and airflow limitation, resulting from abnormalities in the airway and/or damage to the alveoli. Primary care physicians manage the healthcare of a large proportion of patients with COPD. In addition to determining the most appropriate medication regimen, which usually includes inhaled bronchodilators with or without inhaled corticosteroids, physicians are charged with optimizing inhalation device selection to facilitate effective drug delivery and patient adherence. The large variety of inhalation devices currently available present numerous challenges for physicians that include: (1) gaining knowledge of and proficiency with operating different device classes; (2) identifying the most appropriate inhalation device for the patient; and (3) providing the necessary education and training for patients on device use. This review provides an overview of the inhalation device types currently available in the United States for delivery of COPD medications, including information on their successful operation and respective advantages and disadvantages, factors to consider in matching a device to an individual patient, the need for device training for patients and physicians, and guidance for improving treatment adherence. Finally, the review will discuss established and novel tools and technology that may aid physicians in improving education and promoting better adherence to therapy.

The function and performance of aqueous aerosol devices for inhalation therapy

OBJECTIVES

In this review paper, we explore the interaction between the functioning mechanism of different nebulizers and the physicochemical properties of the formulations for several types of devices, namely jet, ultrasonic and vibrating-mesh nebulizers; colliding and extruded jets; electrohydrodynamic mechanism; surface acoustic wave microfluidic atomization; and capillary aerosol generation.

KEY FINDINGS

Nebulization is the transformation of bulk liquids into droplets. For inhalation therapy, nebulizers are widely used to aerosolize aqueous systems, such as solutions and suspensions. The interaction between the functioning mechanism of different nebulizers and the physicochemical properties of the formulations plays a significant role in the performance of aerosol generation appropriate for pulmonary delivery. Certain types of nebulizers have consistently presented temperature increase during the nebulization event. Therefore, careful consideration should be given when evaluating thermo-labile drugs, such as protein therapeutics. We also present the general approaches for characterization of nebulizer formulations.

SUMMARY

In conclusion, the interplay between the dosage form (i.e. aqueous systems) and the specific type of device for aerosol generation determines the effectiveness of drug delivery in nebulization therapies, thus requiring extensive understanding and characterization.

Inhalation drug delivery devices: technology update

The pulmonary route of administration has proven to be effective in local and systemic delivery of miscellaneous drugs and biopharmaceuticals to treat pulmonary and non-pulmonary diseases. A successful pulmonary administration requires a harmonic interaction between the drug formulation, the inhaler device, and the patient. However, the biggest single problem that accounts for the lack of desired effect or adverse outcomes is the incorrect use of the device due to lack of training in how to use the device or how to coordinate actuation and aerosol inhalation. This review summarizes the structural and mechanical features of aerosol delivery devices with respect to mechanisms of aerosol generation, their use with different formulations, and their advantages and limitations. A technological update of the current state-of-the-art designs proposed to overcome current challenges of existing devices is also provided.

Long-Term Efficacy and Safety of Ipratropium Bromide plus Fenoterol via Respimat((R)) Soft Misttrade mark Inhaler (SMI) versus a Pressurised Metered-Dose Inhaler in Asthma

OBJECTIVE

Respimat((R)) Soft Misttrade mark Inhaler (SMI) is a novel, propellant-free device that significantly increases lung deposition compared with pressurised metered-dose inhalers (pMDIs). The aim of this study was to compare the efficacy and safety of ipratropium bromide/fenoterol hydrobromide (IB/FEN; Berodual((R))) delivered via Respimat((R)) SMI and via a chlorofluorocarbon (CFC)-driven pMDI (CFC-MDI) in patients with asthma.

DESIGN

Multicentre, randomised, double-blind, placebo-controlled, parallel- group study.

PATIENTS

631 patients (18-65 years old) with stable asthma.

INTERVENTIONS

After a 2-week run-in period (IB/FEN 20mug/50mug via CFC-MDI, two actuations four times a day), patients were randomised to 12 weeks' treatment with one of five treatments: IB/FEN 10mug/25mug, 20mug/50mug or placebo via Respimat((R)) SMI (one actuation four times a day), or IB/FEN 20mug/50mug or placebo via CFC-MDI (two actuations four times a day). The main efficacy measure was lung function (assessed on days 1, 29, 57 and 85); safety was assessed by monitoring adverse events.

RESULTS

Bronchodilator responses to IB/FEN were much greater than those to placebo (mean peak increases in forced expiratory volume in 1 second [FEV(1)] on day 85: 0.498-0.521L, active treatment; 0.215 and 0.240L, placebo). According to the primary endpoint, i.e. the average change in FEV(1) from test-day baseline over the 6 hours after dosing on day 85, neither IB/FEN dosage via Respimat((R)) SMI was inferior to IB/FEN via pMDI (p < 0.001). Non-inferiority of the two Respimat((R)) SMI dosages was supported by analyses of other lung function measures, e.g. average change in FEV(1) from test-day baseline over the 6 hours after dosing on the other 3 test days, and peak FEV(1) on all test days. Overall, the safety profile of IB/FEN via Respimat((R)) SMI was comparable to that via CFC-MDI.

CONCLUSION

IB/FEN from Respimat((R)) SMI is as effective and safe as from CFC-MDI and enables a 2- to 4-fold daily dose reduction of IB/FEN.

Practical aspects of inhaler use in the management of chronic obstructive pulmonary disease in the primary care setting

Sustained bronchodilation using inhaled medications in moderate to severe chronic obstructive pulmonary disease (COPD) grades 2 and 3 (Global Initiative for Chronic Obstructive Lung Disease guidelines) has been shown to have clinical benefits on long-term symptom control and quality of life, with possible additional benefits on disease progression and longevity. Aggressive diagnosis and treatment of symptomatic COPD is an integral and pivotal part of COPD management, which usually begins with primary care physicians. The current standard of care involves the use of one or more inhaled bronchodilators, and depending on COPD severity and phenotype, inhaled corticosteroids. There is a wide range of inhaler devices available for delivery of inhaled medications, but suboptimal inhaler use is a common problem that can limit the clinical effectiveness of inhaled therapies in the real-world setting. Patients' comorbidities, other physical or mental limitations, and the level of inhaler technique instruction may limit proper inhaler use. This paper presents information that can overcome barriers to proper inhaler use, including issues in device selection, steps in correct technique for various inhaler devices, and suggestions for assessing and monitoring inhaler techniques. Ensuring proper inhaler technique can maximize drug effectiveness and aid clinical management at all grades of COPD.

Clinical effectiveness of the Respimat inhaler device in managing chronic obstructive pulmonary disease: evidence when compared with other handheld inhaler devices

Objectives:

Medication for the management of chronic obstructive pulmonary disease (COPD) may be delivered by a number of different inhaler devices. This study was undertaken to determine the clinical effectiveness of the Respimat^® handheld inhaler device compared with other handheld inhaler devices for the delivery of medication in stable COPD.

Methodology:

A systematic review of high-quality randomized controlled clinical trials comparing Respimat with other inhaler devices using the same medication was performed. Studies were searched for in the Cochrane Central Register of Controlled Trials as well as other relevant electronic databases. Manufacturers of inhaled COPD medication were also contacted for potential trials.

Results:

Seven studies of high methodological quality with 3813 participants were included in the review. Three trials used Handihaler^® as the comparator inhaler, three used a chlorofluorocarbon metered-dose inhaler (CFC-MDI), and one trial used a hydroflouroalkane (HFA)-MDI. When Respimat was compared with Handihaler, the following reported outcomes were not significantly different: trough forced expiratory volume in 1 second (FEV₁) (weighted mean difference [WMD] 0.01 L; P = 0.14), trough forced vital capacity (FVC) (WMD 0.001 L: P = 0.88), peak FEV₁ (WMD 0.01 L: P = 0.08), peak FVC (WMD 0.01 L: P = 0.55), morning peak expiratory flow rate (PEFR) (WMD 5.06 L/min: P = 0.08), and evening PEFR (WMD 4.39 L/min: P = 0.15). Furthermore, there were no differences when Respimat was compared with Handihaler for risk of exacerbations (relative risk [RR] 0.94: P = 0.81), dry mouth (RR 1.57: P = 0.34), or nasopharyngitis (RR 1.42: P = 0.22). For Respimat compared with CFC-MDI, the only outcome for which data were available for meta-analysis was exacerbations, which were not significantly different (RR 1.20: P = 0.12). In addition, five trials with 2136 patients showed that there was no difference in risk of exacerbations or nasopharyngitis when Respimat was compared with all other handheld inhaler devices (RR 1.18: P = 0.13 and RR 1.33: P = 0.19, respectively). None of the clinical outcome measures reported was significantly different when the same, higher, or lower doses of medication were used in the inhaler devices being compared. Unfortunately, none of the included trials reported mortality as an outcome measure.

Conclusions:

Evidence from high-quality trials published to date suggests that the Respimat inhaler does not provide any additional clinical benefit to that provided by other inhaler devices in the management of COPD. Although in vitro studies have reported differences between the Respimat inhaler device and other handheld devices, we found no difference in any clinical outcome measures, including lung function and adverse events. Although recent reports have highlighted concerns of increased mortality with the Respimat inhaler device, none of the included trials reported mortality as an outcome. Only a small number of trials reported data that could be used in this systematic review, and a limited number of studies have been published that compare Respimat with other inhaler devices using the same drug and strength. Therefore, further trials comparing Respimat with other handheld inhaler devices using the same drug and dose are required before firm conclusions can be drawn. The concern with increased mortality with Respimat use should be investigated urgently.

Clinical efficacy and safety of the combination of ipratropium bromide and fenoterol inhaled via the Respimat Soft Mist inhaler for relief of airflow obstruction

Bronchodilators are key drugs in symptomatic as well as maintenance treatment of obstructive lung diseases such as chronic obstructive pulmonary disease and asthma. The short-acting anticholinergic ipratropium bromide and the short-acting beta(2)-adrenergic receptor agonist fenoterol hydrobromide have been available for combined use both as a pressurized metered-dose inhaler and as a solution for nebulization. Their combination at half the dose in the novel device, the Respimat Soft Mist inhaler (RMT), has been shown to provide therapeutic equivalence to their combination into a conventional pressurized metered-dose inhaler, both in terms of efficacy and safety in patients with chronic obstructive pulmonary disease or asthma, both adults and children. Dose reduction with the RMT has been made possible due to the physical characteristics of the aerosol cloud emitted from the RMT, facilitating correct inhalation and ensuring higher pulmonary deposition of the aerosolized bronchodilators. Post-marketing studies using validated questionnaires confirm a high level of satisfaction with the performance and convenience of the RMT device, a large majority of patients preferring the RMT to other inhaler systems.

[Bronchial asthma and chronic obstructive pulmonary disease with acute exacerbation: preclinical differential diagnostic and emergency treatment]

Chronic obstructive pulmonary disease (COPD) and bronchial asthma are the most common causes of obstructive pulmonary diseases and acute dyspnoea. In the preclinical emergency situation a distinction between bronchial asthma and exacerbated COPD is difficult because symptoms are similar. Although the preclinical measures differ only marginally, a differential diagnosis from other causes of respiratory obstruction and acute dyspnoea, such as cardiac decompensation, anaphylaxis, aspiration of foreign bodies, tension pneumothorax and inhalation trauma is necessary because alternative treatment options are required. In the treatment of COPD and bronchial asthma inhalative bronchodilatory beta(2)-mimetics are the first choice especially for serious obstructive emergencies because there is an unfavorable relationship between effect and side-effects for the intravenous route. Dosable aerosols, nebulization and if necessary, continuous nebulization, are appropriate application forms even for serious obstructive crises with the need of a respirator. In these cases a minimal inspiratory flow in patients is not required. Theophylline only plays a minor role to beta(2)-mimetics and anticholinergics as a bronchodilator in asthma and COPD guidelines, even in serious obstructive diseases. For severe asthma attacks the administration of magnesium is a possible additional option. Systemic intravenous administration of steroids has an anti-inflammatory effect and for this reason is the second column of treatment for both diseases. Invasive ventilation remains a last resort to ensure respiratory function and indications for this are given in patients with clinical signs of impending exhaustion of breathing.

Use of Respimat Soft Mist inhaler in COPD patients

Events of the past decade have stimulated development of new drug formulations and delivery devices that have improved the efficiency, ease of use, and environmental impact of inhaled drug therapy. Respimat^® Soft Mist™ Inhaler is a novel, multidose, propellant-free, hand-held, liquid inhaler that represents a new category of inhaler devices. The aerosol cloud generated by Respimat contains a higher fraction of fine particles than most pressurized metered dose inhalers (pMDIs) and dry powder inhalers (DPIs), and the aerosol spray exits the inhaler more slowly and for a longer duration than with pMDIs. This translates into higher lung drug deposition and lower oropharyngeal deposition, making it possible to give lower nominal doses of delivered drugs without lowering efficacy. In clinical trials in patients with COPD, bronchodilator drugs delivered from Respimat were equally effective at half of the dose delivered from a pMDI. In one study of inhaler preference, Respimat was preferred over the pMDI by patients with COPD and other obstructive lung diseases. Respimat is a valuable addition to the range of inhaler devices available to the patient with COPD.

A review of the development of Respimat Soft Mist Inhaler

Respimat Soft Mist Inhaler (SMI) is a new generation inhaler from Boehringer Ingelheim developed for use with respiratory drugs. The device functions by forcing a metered dose of drug solution through a unique and precisely engineered nozzle (the uniblock), producing two fine jets of liquid that converge at a pre-set angle. The collision of these two jets generates the soft mist. The soft mist contains a high fine particle fraction of approximately 65 to 80%. This is higher than aerosol clouds from conventional portable inhaler devices, such as pressurised metered dose inhalers (pMDIs) and dry powder inhalers (DPIs). In addition, the relatively long generation time of the aerosol cloud (approximately 1.5s) facilitates co-ordination of inhalation and actuation--a major problem with pMDIs. These features, together with the slow velocity of the soft mist, result in larger amounts of the drug reaching the lungs and less being deposited in the oropharynx compared with either pMDIs or DPIs. Generation of the soft mist from Respimat SMI is purely mechanical, so propellants are not necessary. The innovative design of Respimat SMI, using water-based drug formulations, ensures patients receive consistent and reliable doses of the drug with each actuation. The device was initially tested in scintigraphic lung deposition studies and produced encouraging results when compared with the chlorofluorocarbon-based pMDI (CFC-MDI). Subsequent clinical studies have confirmed that Respimat SMI is effective and safe in delivering bronchodilators to patients with asthma or chronic obstructive pulmonary disease.

Low incidence of paradoxical bronchoconstriction with bronchodilator drugs administered by Respimat Soft Mist inhaler: results of phase II single-dose crossover studies

BACKGROUND AND OBJECTIVES

Respimat Soft Mist Inhaler (SMI) is an innovative device that offers improved lung deposition and is an environmentally friendly alternative to conventional, chlorofluorocarbon-containing metered-dose inhalers (CFC-MDIs). The aqueous formulations of bronchodilator drugs administered from Respimat SMI contain low concentrations of ethylene diamine tetra-acetic acid (EDTA), a stabilising agent, and benzalkonium chloride (BAC), an antibacterial agent, both of which have been associated with bronchoconstriction when administered via nebulisers. The aim of this retrospective analysis was to compare the incidence of paradoxical bronchoconstriction with bronchodilator drugs administered via Respimat SMI or a CFC-MDI in patients with asthma or chronic obstructive pulmonary disease (COPD).

METHODS

Nine randomised, active- and/or placebo-controlled, double-blind, crossover studies, in which asthmatic and COPD patients (n = 444 and n = 216, respectively) received a beta(2)-agonist and/or anticholinergic or placebo via Respimat SMI or CFC-MDI, were included in the analysis. The incidence of conditions indicative of paradoxical bronchoconstriction were collated and divided into four categories: (1) 'bronchospasm'; (2) two or more of the following events: 'other respiratory adverse events', 'rescue medication use' or 'asymptomatic drop in forced expiratory volume in one second' (FEV(1)); (3) either 'rescue medication use' or 'other respiratory adverse event'; (4) 'asymptomatic drop in FEV(1)'.

RESULTS

The incidence of adverse events indicative of paradoxical bronchoconstriction was low in those patients using the Respimat SMI device, and similar to that seen in the CFC-MDI group. In addition, the incidence of adverse events indicative of paradoxical bronchoconstriction observed in the Respimat SMI group was similar for BAC + EDTA and BAC-only drug formulations.

CONCLUSIONS

These studies demonstrate that, due to the extremely low absolute amounts of BAC and EDTA delivered to the lungs by the device, Respimat SMI is safe with regard to paradoxical bronchoconstriction in patients with asthma or COPD.

A review of ipratropium bromide/fenoterol hydrobromide (Berodual) delivered via Respimat Soft Mist Inhaler in patients with asthma and chronic obstructive pulmonary disease

Asthma and chronic obstructive pulmonary disease (COPD) can be effectively treated by the use of bronchodilator therapies delivered by inhalation. Berodual is a fixed combination of the anticholinergic agent ipratropium bromide (IB) and the beta2-adrenergic agonist fenoterol hydrobromide (FEN). IB/FEN has been available for the treatment of asthma and COPD in a pressurised metered dose inhaler (MDI) [pMDI] formulation for many years. The pMDI is the most widely used device for the delivery of inhaled medications, such as IB/FEN. However, most conventional pMDIs contain chlorofluorocarbon (CFC) propellants, which are currently being withdrawn because of their detrimental effects on the environment. This has resulted in alternative methods of drug delivery being developed. Respimat Soft Mist Inhaler (SMI) is a new generation, propellant-free inhaler that generates a fine, slow-moving cloud (the Soft Mist) which can be easily inhaled. Scintigraphic studies have shown that this improves deposition of drugs in the lung and results in less oropharyngeal deposition than the CFC-MDI. A clinical development programme has been conducted to compare the efficacy and safety of IB/FEN delivered via Respimat SMI with that of IB/FEN via CFC-MDI in the treatment of patients with asthma or COPD. Five clinical studies (two phase II and three phase III) investigated dosages of IB/FEN 5/12.5 microg to 320/800 microg via Respimat SMI in single and multiple dose administration regimens. Four of the trials were conducted in patients with asthma (three in adults and one in children), while one phase III trial was conducted in patients with COPD. In phase III, 2058 patients participated, with a total of 1112 patients treated with IB/FEN via Respimat SMI. In the phase III studies, each dose from Respimat SMI was given in one actuation compared with two actuations with the CFC-MDI. In the paediatric asthma phase III study, all CFC-MDI doses were delivered via a spacer device. The results of the trials demonstrated that IB/FEN via Respimat SMI allows a reduction in the nominal dose of IB/FEN, while offering similar therapeutic efficacy and safety to a CFC-MDI. In children, Respimat SMI obviates the need for a spacer.

Improved delivery of ipratropium bromide/fenoterol from Respimat® Soft MistTM Inhaler in patients with COPD

We performed a multicentre, randomised, double-blind (within-device), placebo- and active-controlled, parallel-group study to compare the efficacy and safety of ipratropium bromide plus fenoterol hydrobromide (IB/FEN; Berodual) delivered via the novel, propellant-free Respimat Soft Mist Inhaler (SMI) and from a chlorofluorocarbon (CFC)-metered-dose inhaler (MDI) in moderate-to-severe chronic obstructive pulmonary disease (COPD) patients. After 2-weeks' run-in (CFC-MDI [IB 20 microg/FEN 50 microg per actuation] two actuations q.i.d. [MDI 40/100]), 892 patients were randomised to Respimat SMI containing IB 10 microg/FEN 25 microg (Respimat SMI 10/25), IB 20 microg/FEN 50 microg (Respimat SMI 20/50) or placebo (one actuation q.i.d.), or a CFC-MDI containing IB 20 microg/FEN 50 microg (MDI 40/100) or placebo (two actuations q.i.d.) for 12 weeks. Analysis of the primary endpoint (change in forced expiratory volume in 1 s [FEV1] in the first 60 min after dosing [area under the curve; AUC0-1h]) on day 85 showed that the efficacy of Respimat SMI 20/50 (but not Respimat SMI 10/25) was not inferior to that of MDI 40/100. The safety profile of Respimat SMI was comparable to CFC-MDI. Switching from MDI 40/100 to Respimat SMI was well tolerated. Respimat SMI enables a 50% reduction of the nominal inhaled dose of IB/FEN in COPD patients while offering similar therapeutic efficacy and safety to the CFC-MDI.

Efficacy and safety of ipratropium bromide plus fenoterol inhaled via Respimat Soft Mist Inhaler vs. a conventional metered dose inhaler plus spacer in children with asthma

The objective of this study was to compare the efficacy and safety of ipratropium bromide/fenoterol hydrobromide (IB/FEN; Berodual) delivered from the novel propellant-free Respimat Soft Mist Inhaler (SMI) with that from a chlorofluorocarbon (CFC) metered-dose inhaler (MDI) plus spacer in children with asthma. The study followed a multicenter, randomized, double-blind (within Respimat SMI), parallel-group design. During the 2-week run-in period, patients received two actuations of CFC-MDI tid (IB 20 microg/FEN 50 microg per actuation) via a spacer (Aerochamber) (MDI 40/100). Patients (n=535) were then randomized to: Respimat SMI containing IB 10 microg/FEN 25 microg (Respimat SMI 10/25), IB 20 microg/FEN 50 microg (Respimat SMI 20/50), one actuation tid or CFC-MDI containing IB 20 microg/FEN 50 microg per actuation (in total 1B 40 microg/FEN 100 microg), or two actuations tid via Aerochamber (MDI 40/100), for 4 weeks. The primary endpoint was the change in forced expiratory volume in 1 second (FEV1) during the first 60 min after dosing (area under the curve from 0-1 h [AUC(0-1 h)]) on day 29. Analysis of the primary endpoint demonstrated that the efficacy of Respimat SMI 10/25 and 20/50 was equivalent to or greater than that of MDI 40/100. Similar results indicating that Respimat SMI 10/25 and 20/50 were not inferior to MDI 40/100 were also found on days 1 and 15. Analyses of other secondary endpoints supported these results. The safety profile of Respimat SMI was comparable to that of the CFC-MDI plus spacer. In conclusion, IB/FEN delivered via Respimat SMI is at least as effective as, and is as safe as, when delivered via CFC-MDI plus Aerochamber in children with asthma. Use of Respimat SMI thus enables a 2-4-fold reduction in the nominal dose of IB/FEN, and obviates the need for a spacer.

Anticholinergic agents for chronic asthma in adults

BACKGROUND

Anticholinergic agents such as ipratropium bromide are sometimes used in the treatment of chronic asthma. They effect bronchodilation and have also been used in combination with beta2-agonists in the management of chronic asthma.

OBJECTIVES

To examine the effectiveness of anticholinergic agents versus placebo and in comparison with beta2-agonists or as adjunctive therapy to beta2-agonists.

SEARCH STRATEGY

The Cochrane Airways Group asthma and wheeze database was searched with a pre-defined search strategy. Searches were current as of August 2003. Reference lists of articles were also examined.

SELECTION CRITERIA

Randomised trials or quasi-randomised trials were considered for inclusion. Studies assessing an anticholinergic agent versus placebo or in combination/comparison with beta2-agonists were included. In practice, all beta2-agonists were short acting. Short-term (less than 24 hours duration) and longer-term studies were separated; the latter are reported in this review and the former in the review, "Anticholinergic agents for chronic asthma in adults short term".

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed abstracts for retrieval of full text articles. Papers were then assessed for suitability for inclusion in the review. Data from included studies were extracted by two reviewers and entered into the software package (RevMan 4.2). We contacted authors for missing data and some responded. Adverse effect data were analysed if reported in the included studies.

MAIN RESULTS

The studies analysed were in two groups: those comparing anticholinergics with placebo and those comparing the combination of anticholinergics with short acting beta2-agonists versus short acting beta2-agonists alone. The former group had 13 studies involving 205 participants included in this review, and the latter 9 studies involving 440 patients. Generally methodological quality was poorly reported, and there were some reservations with respect to the quality of the studies. Despite the limited number of studies that could be combined, anticholinergic agents in comparison with placebo resulted in more favourable symptom scores particularly in respect of daytime dyspnoea (WMD -0.09 (95%CI -0.14, -0.04, 3 studies, 59 patients). Daily peak flow measurements also showed a statistically significant improvement for the anticholinergic (e.g. morning PEF: WMD =14.38 litres/min (95%CI 7.69, 21.08; 3 studies, 59 patients). However the clinical significance is small and in terms of peak flow measurements equates to approximately a 7% increase over placebo. The more clinically relevant comparison of a combination of anticholinergic plus short acting beta2-agonist versus short acting beta2-agonist alone gave no evidence in respect of symptom scores or peak flow rates of any significant differences between the two regimes. Again there are reservations with respect to the quality of the information from which these conclusions are drawn.

REVIEWERS' CONCLUSIONS

Overall this review provides no justification for routinely introducing anticholinergics as part of add-on treatment for patients whose asthma is not well controlled on standard therapies. This does not exclude the possibility that there may be a sub-group of patients who derive some benefit and a trial of treatment in individual patients may still be justified. The role of long term anticholinergics such as tiotropium bromide has yet to be established in patients with asthma and any future trials might draw on the messages derived from this review.

Fenoterol delivery by Respimat soft mist inhaler versus CFC metered dose inhaler: cumulative dose-response study in asthma patients

OBJECTIVES

Respimat (RMT) soft mist inhaler (SMI) is a novel, propellant-free alternative to chlorofluorocarbon metered-dose inhalers (CFC-MDIs). The aim of this study was to evaluate the safety and establish the equipotent dose of fenoterol delivered by RMT SMI vs. a conventional MDI.

DESIGN

Double-blind, randomized, crossover, comparative study between fenoterol inhaled via RMT (either 50 microg/actuation, RMT50; or 100 microg/actuation. RMT100) and MDI (100 microg/actuation; MDI100).

PATIENTS AND INTERVENTIONS

A total of 41 asthma patients received cumulative doses of fenoterol 600 microg (RMT50) or 1200 microg (RMT100 and MDI100) on 3 test days.

MEASUREMENTS AND RESULTS

The bronchodilator response (forced expiratory volume in 1 second [FEV1]) was considered therapeutically equivalent (i.e., noninferior) if the 95% confidence intervals for the difference in their mean changes from baseline were within limits of +/- 0.15L. Systemic exposure was evaluated from plasma fenoterol levels. Adverse events (AEs) were recorded. RMT50 and RMT100 produced noninferior bronchodilatation to MDI100 from 30minutes after the first dose. RMT50 showed equivalent safety and tolerability to MDI100, whereas RMT100 produced a higher incidence of AEs, a significantly greater plasma potassium reduction and a significant increase in pulse rate. Fenoterol plasma levels were twice as high with RMT100 as with RMT50 or MDI100. CONCLUSIONS; The nominal dose of fenoterol administered via RMT SMI can be at least halved to achieve equivalent efficacy, safety, and tolerability to a MDI.

Pressurised metered dose inhalers versus all other hand-held inhaler devices to deliver beta-2 agonist bronchodilators for non-acute asthma

BACKGROUND

A number of different inhaler devices are available to deliver beta2-agonist bronchodilators in asthma. These include hydrofluoroalkane (HFA) or chlorofluorocarbon (CFC)-free propelled pressurised metered dose inhalers (pMDIs) and dry powder devices.

OBJECTIVES

To determine the clinical effectiveness of pMDI compared with any other available handheld inhaler device for the delivery of short-acting beta-2 agonist bronchodilators in non-acute asthma in children and adults.

SEARCH STRATEGY

The Cochrane Collaboration Clinical Trials register was searched for studies as well as separate additional searches carried out on MEDLINE, EMBASE, CINAHL and also on the Current Contents Index as well as the Science Citation Index. In addition, 17 individual online respiratory journals and 12 electronically available clinical trial databases were also searched. The UK pharmaceutical companies who manufacture inhaled asthma medication were contacted in order to obtain details of any published or unpublished studies.

SELECTION CRITERIA

- The full texts of all potentially relevant articles were reviewed independently by two reviewers.

DATA COLLECTION AND ANALYSIS

Fixed and random effect models were used. Dichotomous outcomes were assessed using Odds Ratios or Relative Risks (RR) with 95% Confidence Intervals (95%CI).

MAIN RESULTS

Eighty-four randomised controlled trials were included in this review, but few could be combined to assess a specific outcome for a given delivery device comparison. Only two studies required demonstration of adequate pMDI technique as an entry requirement. There were no difference between a standard CFC containing pMDI and any other device for most outcomes. Regular use of HFA-pMDI containing salbutamol reduced the requirement for short courses of oral corticosteroids (3 trials, 519 patients: RR 0.67; 95% CI 0.49, 0.91); however the total number of exacerbations were unchanged (3 trials, 1271 patients: RR 1.0; 95% CI 0.75, 1.33).

REVIEWER'S CONCLUSIONS

In patients with stable asthma, short-acting beta-2 bronchodilators in standard CFC-pMDI's are as effective as any other devices. The effect of HFA-pMDI on requirement for oral corticosteroid courses to treat acute exacerbations should be confirmed. Effectiveness studies that use an intention-to-treat analysis are required.

Electro-hydrodynamic atomization of drug solutions for inhalation purposes

Monodisperse aerosols show therapeutic advantages, but they are difficult to generate. A new method (electrohydrodynamic atomization) is described. A high voltage is applied to a nozzle through which a solution, containing dissolved drug, is pumped. At the nozzle tip, a liquid cone is formed and a stream of monodisperse droplets is released. The droplet diameter is governed by the density, conductivity, and the flow rate of the fluid. The droplets are charged and need to be neutralized. Therefore, a corona discharge system is used. Methylparahydroxybenzoate was used as a model drug, and additional data were generated by using beclomethasone dipropionate (BDP). At a flow rate of 1 ml/h and 0.5% methylparahydroxybenzoate, 1.58-microm particles were produced with a geometric SD of 1.18. Increasing the flow rate to 3 ml/h and the concentration to 3% resulted in 4.55-microm particles with a geometric SD of 1.29. The experiments with BDP resulted in similar particle sizes. The mass of BDP was found to range between 1.42 and 6 microg/l air. Aqueous solutions cannot be sprayed by using this setup. This method can be used to deliver antiasthma drugs to patients.