Actions of salbutamol, disodium cromoglycate, and placebo administered as aerosols in acute asthma.

Abstract

Little is known about the relative actions of placebo in the acute attack and between attacks. In this study the actions were compared of inhaled salbutamol, inhaled DSCG, and placebo, early and late, in an acute attack of asthma. MethodsThe 35 children studied were admitted with an acute attack of asthma. Fifteen were examined on two occasions late in the attack, and 20 were examined on one occasion early in the attack.Fifteen were examined the following morning, 12-24 hours after admission and again the next day. On the first occasion alternate patients received the drug regimen: placebo (sterile water for injections BP) 2 ml given after measurement of the initial peak expiratory flow rate (PEFR), followed 30 minutes later by salbutamol 5 mg in 2 ml of solution, and 60 minutes later by DSCG 20 mg in 2 ml of solution. Alternate patients received the drugs in the reverse sequence, placebo-DSCG-salbutamol. Preliminary observations had shown that the placebo effect was complete at about 30 minutes, but it is possible that water in the DSCG + salbutamol preparations could have contributed to apparent drug effects, but this does not invalidate the comparison between the drugs. PEFR measurements were repeated at 5-minute intervals throughout the study, and values at 30, 60, and 90 minutes, when maximum effects for each treatment had been reached, were used for statistical analysis. The same children were examined 24 hours later by the alternative drug sequence. A child was eliminated from the study and not given the second sequence if the PEFR failed to be within ± 10O of the value on the first day. In this way the children chosen were ones in whom recovery was prolonged and the clinical state was fairly stable. None of these children was breathless at rest or had tachypnoea, but there was wheeze, and rhonchi were 722 on 11 May 2018 by guest. Protected by copyright.

Evidence based general practice: a retrospective study of interventions in one training practice

“…Primary interventions were classified “evidence based” if they fulfilled the criteria for category (i) or (ii), with the result that 81% of patients (82/101) had received evidence based interventions (tables 1 and 2) 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33. The remaining 19% (table 3) were judged to have received treatment that had no substantial evidence from our search.…”

Bronchodilator effect of disodium cromoglycate administered as a dry powder in exercise induced asthma.

“…This study does not help to elucidate the mechanism of action of DSCG as a bronchodilator. Although when given after exercise it may act, in part, by preventing on going mast cell degranulation this would not account for its bronchodilator properties when given in the resting state as shown by us and others (Chung & Jones, 1979;Hasham et al, 1981;Corkey et al, 1982;Jones et al, 1983).…”

“…The site of deposition of inhaled particles is also influenced 3.4r by differences in technique of inhalation, tidal breathing tending to distribute aerosols more diffusely throughout the lungs, whilst vital capacity inhalation results in more central deposition (Dolovich et al, 1979 This study does not help to elucidate the mechanism of action of DSCG as a bronchodilator. Although when given after exercise it may act, in part, by preventing on going mast cell degranulation this would not account for its bronchodilator properties when given in the resting state as shown by us and others (Chung & Jones, 1979;Hasham et al, 1981;Corkey et al, 1982;Jones et al, 1983).…”

“…It has been stated to have no bronchodilator properties, but recent evidence suggests that this is not the case (Chung & Jones, 1979;Hasham et al, 1981;Jones et al, 1983). Previous studies all used DSCG as a pressurised aerosol or respiratory solution and we undertook this study to determine if the dry powder, delivered by the spinhaler, possessed similar properties.…”

Furosemide Inhalation in Dyspnea of Mustard Gas-Exposed Patients: A Triple-Blind Randomized Study

“…The placebo effect may be due to the nebulized form of use, decreasing respiratory rate or increasing the airways humidity (Noseda et al, 1997). Some suggest that this effect is due to the action of water on the surface film of surfactant, thus decreasing airways resistance (Hasham et al, 1981). However, the exact mechanism needs to be elucidated.…”