Conditions: Asthma
Keywords: asthma, corticosteroids, bronchodilator, airway blood flow
Allocation: RANDOMIZED | Intervention model: CROSSOVER
Enrollment: 14
Healthy volunteers: no

Brief summary:
The addition of an inhaled long-acting beta-adrenergic agonist to an inhaled glucocorticosteroid improves disease control in persistent asthma. This observation has supported the use of long-acting beta-adrenergic agonist/glucocorticosteroid combination preparations for the management of asthma. Currently, salmeterol/fluticasone and formoterol/budesonide are available for clinical use. The long-term beneficial clinical effects of the two drug classes seem to be synergistic, and several mechanisms of glucocorticoid-beta-adrenergic agonist interactions involving gene transcription have been invoked to explain this phenomenon.This study, wish to address the question whether glucocorticoids can acutely potentiate the bronchodilator response to a long-acting beta-adrenergic agonist.We expect that in patients with asthma, the short-term bronchodilator effect of salmeterol is enhanced by the addition of fluticasone, which by itself has no short-term bronchodilator effect. To test this premise, we will assess the respective short-term effects of salmeterol (50 µg), fluticasone (250 µg), salmeterol/fluticasone (50/250 µg), and placebo/placebo on spirometric parameters. Airway Blood flow will also be measured to ensure that vasoconstriction does not occur.

Detailed description:
Fourteen lifetime nonsmokers with a physician diagnosis of asthma will be recruited for the study. All subjects will be allowed to use short-acting beta-adrenergic agonists as rescue medication.

Inclusion criteria:

1. Males and females, 18 to 65 years of age.
2. FEV1 60-85% of predicted on the screening day.

Exclusion criteria:

1. Women of childbearing potential who do not use accepted birth control measures; pregnant and breast feeding women.
2. Cardiovascular disease and/or use of cardiovascular medications

2\. Subjects with known beta-adrenergic agonist or glucocorticosteroid intolerance 4. Acute respiratory infection within four weeks prior to the study 5. Use, within two weeks prior to the study, of any anti-asthma medication not mentioned above

Arms:
arm 1: participants were treated fluticasone/salmeterol, arm 2: participants were treated with salmeterol arm 3: participants were treated with fluticasone arm 4: participants were treated with placebo

Interventions: intervention 1: fluticasone intervention 2: placebo inhalation intervention 3: Salmeterol intervention 4: fluticasone/salmeterol
Intervention descriptions: intervention 1: 220- mcg once intervention 2: placebo inhalation once intervention 3: 50 mcg salmeterol once intervention 4: inhalation of 250 mcg of fluticasone combined with 50 mcg of salmeterol

Protocol document: