Assessment of a new device for delivering aerosol drugs to asthmatic children.

Abstract

SUMMARY A new device, known as the aerochamber, for delivering aerosol drugs was compared with a standard aerosol inhaler in asthmatic children aged between 5 years 3 months and 13 years 10 months. The study was conducted under doubleblind conditions using fenoterol, a 3 2 stimulant, as the active agent and a placebo. Response to treatment was assessed by measuring the peak expiratory flow rate before and after each inhaler. Seven of 10 children had greater mean improvements in peak expiratory flow rates when receiving the active drug from the aerochamber. The aerochamber offers a method for administering a whole range of canistered packaged drugs to children unable to use the standard inhalers.Conventional pressurised aerosol devices administering metered doses of bronchodilator drugs present certain problems to the young asthmatic child. Co-ordinating activation of the aerosol with inspiration is the main difficulty, and often results in little of the active agent getting to its site of action. A considerable proportion of the dose is deposited in the mouth and pharynx.1 2 Even when used correctly the proportion of the drug administered that reaches the lower respiratory tract is about 5 to 10%.3Attempts have been made to design delivery systems for administering aerosol drugs that overcome the problems of co-ordination and oral deposition.4 5 It is possible to decrease oral deposition by attaching tubes of various lengths and diameters to the activator6 allowing further evaporation of the aerosol vapour after the initial flash of propellent liquid and by reducing initial droplet velocity.7 Incorporating an inhalation valve into the system allows the patient to separate inhalation from activation thereby overcoming the problem of co-ordination often encountered by asthmatic children. This study was designed to compare a conventional aerosol delivery system alone delivering a p 2 stimulant with one attached to an extension tube with an inhalation valve for asthmatic children. The attachment is known as the aerochamber. MethodChildren between ages 5 and 14 years with perennial asthma who required regular daily a 2 stimulantssuch as salbutamol-for the control of asthma were entered into the trial. Each child was given two standard metered dose inhalers, one delivering a placebo, the other 0. 2 mg fenoterol, a ,B 2 stimulant, per activation. The inhalers were labelled A and B under double-blind conditions. The new aerochamber device was attached to either inhaler A or inhaler B. The trial inhalers were used at a set time each day when the child would normally inhale a P 2 stimulant for relief of wheezing. For the rest of the day the children received their regular treatment, but no P 2 stimulant was given during the 4 hours before using the inhalers. The inhalers were always used in a set order, A first followed by B. Before using aerosol A each child recorded the best of three peak expiratory flow efforts using a mini Wright peak flow meter. The child then took two puffs from aerosol A and recorded the peak expir...

Salmeterol Administration by Metered-Dose Inhaler Alone vs Metered-Dose Inhaler Plus Valved Holding Chamber

“…In another adult study, 26 it was reported that patients who are "unable to use a pressurized aerosol efficiently" will achieve greater improvement in pulmonary function using terbutaline with a tube spacer vs an MDI alone. Although most clinical evaluations of spacer devices have found that the response to short-acting ␤ 2 -agonists is equivalent to that achieved with correctly performed MDI technique, [15][16][17][18][19][20][21][22][23] one pediatric study found that the MDI plus a 750-mL spacer was superior to correct use of MDI alone. 31 One adult study of primarily chronic bronchitis patients also showed that a spacer device provided a better response to a short-acting ␤ 2 -agonist.…”

“…5 Numerous trials have demonstrated that a large percentage of patients make errors in using MDI, 6 -11 and evaluations of health professionals reveal similar difficulties. [12][13][14] Studies have shown that spacer devices provide at least equivalent efficacy in patients with optimal MDI technique, [15][16][17][18][19][20][21][22][23] and enhance efficacy of short-acting ␤ 2 -agonists in stable patients who have poor MDI technique. [23][24][25][26] Our review of the literature shows no studies comparing salmeterol MDI alone with salmeterol MDI plus a delivery-enhancement or spacer device.…”

Cámara Aérea para Medicamentos Presurizados

“…La tecnica de inhalation es particularmente importance en nifios de corta edad 11 -12 , en quienes la principal dificultad consiste en sincronizar la inhalation con la descarga, como ocurre con elempleo de dosificadores apresion 13 ' 14 -Varies autores han propuesto diferentes adaptaciones como bolsas colapsables 15 -16 , tubos de extension bucal 12 ' 17 , aerocamaras 13 -18 -19 , las que no siempre resultan efectjvas pues requieren Un esfuerzo respiratorio exclusivamente bucal y ademas aumentan los costos.…”