Drug Compliance in Patients with Bronchial Asthma: Relation among Compliance with Different Types of Antiasthmatic Drug and Association with Daily Administration Frequency

Not only monotherapy with inhaled corticosteroids (ICS) but also the concurrent use of other antiasthmatic agents, including leukotriene receptor antagonists (LTRA), play an important role in the management of asthma. However, few studies have focused on compliance with these drugs and on the relation between drug compliance and drug usage. Data were derived from a survey of pharmacists dispensing antiasthmatic drugs to adults with asthma who visited participating pharmacies from October through November 2002. The patients were limited to regular users of ICS whose medication had not been changed for at least 6 months before the survey. Drug compliance and the daily administration frequency of antiasthmatic agents were evaluated on the basis of pharmaceutical records. Completed data were received for 322 patients. ICS compliance was lower than compliance with oral sustained-released theophylline (OSRT) and compliance with LTRA. ICS compliance significantly correlated with OSRT compliance and with LTRA compliance. There were no significant differences of ICS compliance among ICS alone, ICS + LTRA, ICS + OSRT and ICS + LTRA + OSRT group, while the daily inhalation frequency in ICS + OSRT or ICS + OSRT + LTRA group were higher than those in ICS alone group. Although there was a significant negative correlation between ICS compliance and daily inhalation frequency, neither OSRT compliance nor LTRA compliance significantly correlated with the tablet or capsule numbers per day. These findings indicate that OSRT may increase the compliance of concomitant ICS, and that the compliance of OSRT or LTRA is independent of the numbers of tablets taken per day. These unique characteristics should be considered in the treatment and guidance of patients with bronchial asthma.