Intranasal Corticosteroid Use Prevalence and Adherence in Allergic Rhinitis: A Cross-sectional Study at Community Pharmacies in Singapore

Introduction:

Recent changes to the forensic classification of intranasal corticosteroids (INCS) have enhanced the public’s access to this first-line treatment for allergic rhinitis (AR) at community pharmacies without a prescription. However, the INCS use data among AR patients who visit community pharmacies is unknown.

Objectives:

This study evaluated the prevalence of and adherence to INCS therapy among individuals with moderate-severe AR at community pharmacies in Singapore.

Study Design:

A cross-sectional survey was conducted at thirty-nine branches of a community pharmacy chain (Watson’s Personal Care Stores Pte Ltd) in Singapore from August to December 2014.  

Methods:

Customers who were 21 years old and above and identified with moderate-severe AR symptoms by pharmacists were recruited by pharmacists and project students to complete a self-administered hardcopy/online questionnaire.  AR severity was assessed using the Allergic Rhinitis and its Impact on Asthma (ARIA) classification.  Adherence to the prescribed/recommended INCS dosing regimen was identified using the Morisky Medication Adherence Scale modified for AR.

Results:

Among 283 respondents, 128 (45.2%, 95% CI 39.5% - 51.1%) were on INCS; where majority were prescribed by physicians (71.1%) and recommended by pharmacists (24.2%).  Of the 113 respondents who were instructed to use INCS on a daily basis, 94.7% reported low to medium adherence to the dosing instructions, with the top reason for non-adherence being “stopping the use of INCS when AR symptoms are under control”.

Conclusions:

Despite being the gold standard therapy for moderate-severe AR, INCS were underused.  Although INCS can be directly obtained from community pharmacies without a prescription, the number of INCS recommended by pharmacists was lower than that prescribed by physicians.  Hence community pharmacists can play a greater role in triage and recommendation of INCS for individuals with AR who may benefit from its use, as well as assessment and counseling to improve adherence and appropriate use of INCS.