Antiasthmatic drug delivery in children

Asthma and COPD Patients' Perception of Appropriate Metered-Dose Inhaler Technique

Objectives:

Asthma and chronic obstructive pulmonary disease (COPD) are chronic illnesses of the airways affecting a good number of people in Lebanon and the Middle East. Pressurized metered-dose inhalers (pMDIs) are important drug delivery systems used to treat such pulmonary diseases. Drugs proven to be valuable and effective may fail to act effectively if such inhalers are used incorrectly. The purpose of this study was to assess the technical use of pMDIs by patients with pulmonary diseases presenting to the community pharmacies in Lebanon.

Methods:

A structured questionnaire was developed to collect data. A total of 601 patients using drugs delivered through pMDIs and presenting to 12 Lebanese community pharmacies were recruited to participate in the research project. The questionnaire items were divided into 3 subscales: subscale 1—assessing the device preparation; subscale 2—investigating the device use; and subscale 3—examining the knowledge and use of spacers. After confirming the reliability and validity of the survey tool, patients’ responses were analyzed and compared according to many variables.

Results:

Many patients answered inaccurately to questions assessing both the device preparation and use. Around 40% of patients said they do not coordinate the inhalation with pressing the canister down. The mean scores were 1.72 (± 0.73) over 6 and 5.67 (± 1.44) over 7 for subscales 1 and 2, respectively. The mean total score on all questions was 7.39 over 13, with a standard deviation of 1.75. While patients’ age did not impact the results, asthmatic, well-educated, male patients had fewer wrong answers when it comes to preparing and using the device (P < .01).

Conclusions:

Our study showed that many patients with asthma and COPD might not be properly using their pMDIs. Appropriate inhaler use is crucial for successful pulmonary disease management. As pMDIs are one of the most difficult devices to use, proper and tailored instructions should be given to patients.

Use of spacers for patients treated with pressurized metered dose inhalers: focus on the VENTOLIN™ Mini Spacer

INTRODUCTION

Spacers offer a multitude of benefits by reducing the requirement to coordinate inhalation with actuation and improving inhaler technique in patients using a pressurized metered dose inhaler (pMDI). Spacers improve drug targeting by retaining within the spacer large particles normally deposited in the oropharynx, and by creating a prolonged aerosol cloud of fine particles to give the user increased time to inhale after actuation. This is particularly important in young children and the elderly to effectively deliver medication to the airways.

AREAS COVERED

By investigating the history and features of spacers, we demonstrate that the advantages of using spacers far outweigh their limitations. We also discuss the optimal characteristics of spacers in terms of shape, volume, presence of valve and static charge, and present a detailed discussion of the VENTOLIN™ Mini Spacer.

EXPERT OPINION

Generally, the shape and size of spacers makes them inherently inconvenient. Consideration of human factors and modern design may make them more attractive to patients. However, the incentive to use spacers should be their ability to help patients correctly use inhaled medications delivered by pMDIs. Understanding of these principles through education is key to their acceptance by patients.

Metered-dose inhaler for asthma patients: knowledge and effects of a theoretical and practical guidance for pediatricians

OBJECTIVE

To evaluate the effect of a theoretical and practical guidance on knowledge of pediatricians regarding the use of metered dose inhalers with spacers. To identify major deficiencies, correct them and train these physicians on the correct use of the devices.

METHODS

Pediatricians who participated in a theoretical-practical program focusing on the use of inhaler devices answered a questionnaire with five questions about the use of these devices before and after the program. A comparison of the scores obtained in the pre- and post-training tests was performed by Wilcoxon test for related samples, and a significance level of 0.05 was adopted.

RESULTS

Twenty pediatricians performed pre- and post-training tests. The performance of pediatricians in the post-training test was significantly better than baseline (p<0.001).

CONCLUSION

A brief orientation program for pediatricians significantly improved their knowledge on the use of metered-dose inhalers with spacers, which may translate into an improvement in quality and quantity of prescriptions of these devices in clinical practice. The questions with higher rates of errors in the pre-training test were the questions about the waiting time between two sprays in successive applications and about the correct way to attach the inhaler to the spacer, both with high levels of success in the post-training test.

[Evaluation of the knowledge of health professionals at a pediatric hospital regarding the use of metered-dose inhalers]

OBJECTIVE

To evaluate health professionals working at a tertiary pediatric hospital in terms of their knowledge regarding the practical use of metered-dose inhalers.

METHODS

Practical and written tests on the use of metered-dose inhalers were applied to physicians, physical therapists, nurses and nursing assistants. A score from 0 to 10 was assigned to each evaluation, and median scores were calculated for each professional category. Questions with higher and lower correct values were identified, and a descriptive comparison was made regarding the performance of the various professional categories. Statistical analysis was performed using the Kruskal-Wallis method for comparison of medians. A sequential logistic multiple regression analysis was also performed.

RESULTS

A total of 30 resident physicians or interns in the pediatrics department, 23 attending physicians, 29 physical therapists, 33 nurses and 31 nursing assistants were evaluated. Resident physicians, physical therapists and attending physicians performed significantly better than did nurses and nursing assistants. Only resident physicians had a median score greater than 6.

CONCLUSIONS

The health professionals evaluated, particularly the nurses and nursing assistants, who are directly involved in the practical use of metered-dose inhalers, possess insufficient knowledge regarding the use of such inhalers.

Use of inhaler devices in pediatric asthma

Inhalation is the preferred route for asthma therapy, since it offers a rapid onset of drug action, requires smaller doses, and reduces systemic effects compared with other routes of administration. Unfortunately, inhalation devices are frequently used in an empirical manner rather than on evidence-based awareness.A wide variety of nebulizers are available. Conventional jet nebulizers are highly inefficient, as much of the aerosol is wasted during exhalation. However, incorporating an extra open vent into the system has considerably increased the amount of drug that patients receive. Breath-assisted open vent nebulizers limit the loss of aerosol during exhalation, but are dependent on the patient's inspiratory flow. Ultrasonic nebulizers produce a high mass output and have a short nebulization time, but are inefficient for delivering suspensions or viscous solutions. Adaptive aerosol delivery devices release a precise dose that is tailored to the individual patient's breathing pattern. Nebulizers have several drawbacks, and their use should be limited to patients who cannot correctly manage other devices.Pressurized metered-dose inhalers (pMDI) are practical, cheap and multidose. However, there are several problems with their use. Breath-actuated MDI are easy to use and can be activated by very low flow. However, young children may not be able to use them efficiently. Dry powder inhalers (DPI) are portable and easy to use. They are indicated either for rescue bronchodilator therapy or for regular treatment with inhaled corticosteroids and long-acting bronchodilators. The use of spacers reduces oropharyngeal deposition and improves drug delivery to the lung. Spacers do not require patient coordination, but some general rules must be followed for their optimal use.Thus, the choice of a delivery device mainly depends on the age of the patient, the drug to be administered and the condition to be treated. Proper education is also essential when prescribing an inhalation device.

Pulmonary mucus: Pediatric perspective

Airway mucus hypersecretion is a clinical feature of a number of childhood diseases, including asthma and bronchitis-associated conditions. However, compared with adults, there is relatively scarce information concerning mucus pathophysiology in respiratory diseases in children. The available evidence indicates many similarities between adult and childhood respiratory hypersecretory conditions, including goblet-cell hyperplasia and submucosal gland hypertrophy, and airway mucus plugging in asthma. Consequently, it is likely that treatments that are effective in adults would be effective in children. Numerous therapeutic targets are linked to the pathophysiology of airway mucus hypersecretion in experimental models and adults with respiratory disease. Whether or not these same targets are relevant in children is for the most part unclear. These targets include the inflammatory cells mediating the inflammatory response that generates the hypersecretory phenotype, and highly specific cellular elements such as epidermal growth factor receptor tyrosine kinase and calcium-activated chloride (CACL) channels. Identification of these factors is linked with the development of different classes of pharmacotherapeutic molecules directed at these targets. Compounds with a broader spectrum of anti-inflammatory activity are likely to be more effective than compounds with restricted activity. However, certain highly specific targets, such as human CACL1 channels, appear to be strongly associated with the development of an airway hypersecretory phenotype. Data from current clinical trials in adults with blockers of these specific targets are awaited with great interest. The hope is that, if effective, pediatric trials with these compounds could be initiated with a view to alleviation of the clinical impact of airway mucus hypersecretion in children. A significant challenge to the therapeutic progression of these new compounds is effective delivery to the airways in children, with the research effort into development of new compounds matched by advances in inhaler design.