Randomized controlled trial of adherence with single or combination inhaled corticosteroid/long-acting beta-agonist inhaler therapy in asthma

J Allergy Clin Immunol. 2010 Sep;126(3):505-10. doi: 10.1016/j.jaci.2010.06.033.


Background: The inhaled corticosteroid (ICS)/long-acting beta-agonist (LABA) combination inhaler has the potential to improve adherence with ICS therapy in asthma.

Objective: To determine whether ICS/LABA combination inhaler therapy improves adherence compared with separate inhaler use.

Methods: In a 24-week randomized controlled parallel group study, 111 subjects were prescribed 125 microg fluticasone dipropionate (FP) and 25 microg salmeterol, 2 actuations twice daily through either a combination inhaler or separate inhalers concurrently. Medication use was recorded by covert electronic monitors. The primary outcome variable was adherence during the final 6-week period, defined as the number of doses taken as a percentage of those prescribed.

Results: Complete adherence data from the final 6-week period were available for 49 and 54 subjects in the separate and combination groups, respectively. The mean (SD) adherence was 73.7% (36.0) for FP, 76.7% (30.5) for salmeterol, and 82.4% (24.5) for FP/salmeterol. There were no significant differences in adherence between FP/salmeterol and FP (-8.7%; 95% CI, -10.6 to 3.3) and salmeterol (-5.6%; 95% CI, -16.4 to 5.1). There was no significant difference in overuse among the FP, salmeterol, or FP/salmeterol groups. In 2 (4%) of 49 subjects, salmeterol was effectively taken as monotherapy during a 6-week period.

Conclusion: In the setting of a randomized controlled trial, use of a combination ICS/LABA inhaler does not markedly increase adherence above that observed with separate inhaler use. LABA monotherapy was observed in a small proportion of patients prescribed ICS and LABA therapy via separate inhalers.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Inhalation
  • Adolescent
  • Adrenal Cortex Hormones / administration & dosage
  • Adrenal Cortex Hormones / therapeutic use*
  • Adrenergic beta-Agonists / administration & dosage
  • Adrenergic beta-Agonists / therapeutic use*
  • Adult
  • Anti-Asthmatic Agents / administration & dosage
  • Anti-Asthmatic Agents / therapeutic use*
  • Asthma / drug therapy*
  • Drug Therapy, Combination*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Treatment Outcome


  • Adrenal Cortex Hormones
  • Adrenergic beta-Agonists
  • Anti-Asthmatic Agents