Adherence to Preservative-Free Dorzolamide/Timolol Fixed Combination Assessed by Counting the Unused Single-Dose Units.

Yeon, Dong Yun; Yoo, Chungkwon; Park, Ji Hye; Han, Ji Yun; Kim, Yong Yeon

doi:2015.56.6.906

J Korean Ophthalmol Soc > Volume 56(6); 2015 > Article

Original Article

Journal of the Korean Ophthalmological Society 2015;56(6):906-910.
DOI: https://doi.org/10.3341/jkos.2015.56.6.906 Published online June 15, 2015.

Adherence to Preservative-Free Dorzolamide/Timolol Fixed Combination Assessed by Counting the Unused Single-Dose Units.

Dong Yun Yeon, Chungkwon Yoo, Ji Hye Park, Ji Yun Han, Yong Yeon Kim

Department of Ophthalmology, Korea University College of Medicine, Seoul, Korea. augen@lycos.co.kr

무보존제 도졸라마이드-티몰롤 복합제제의 미사용 용기 확인을 통한 녹내장 환자의 순응도 평가

연동윤⋅유정권⋅박지혜⋅한지윤⋅김용연

고려대학교 의과대학 안과학교실

Received: 24 October 2014 • Revised: 10 December 2014 • Accepted: 20 April 2015

Abstract

PURPOSE
To investigate the actual adherence to treatment with preservative-free dorzolamide-timolol fixed combination (DTFC) eyedrops of primary open-angle glaucoma (POAG) patients by counting the number of unused single-dose units of DTFC. METHODS: This study included 34 POAG patients newly prescribed with preservative-free DTFC eyedrops (formulated in single-dose units). The enrolled patients were asked to bring the unused DTFC units on their next visit after 2 weeks of treatment with DTFC. On their second visit, they were asked to complete a questionnaire regarding the self-reported adherence and the number of unused DTFC single-dose units was counted. The actual adherence (%) was calculated by dividing the expected number of used DTFC units by the actual number of used DTFC units. The correlation between the self-reported adherence and the measured adherence was assessed. RESULTS: Twenty-nine (93.5%) patients answered they adhered to the medication by more than 90% and 2 (6.5%) answered they instilled the eyedrops at 80-90% of the dosing schedule. However, after counting the unused DTFC single-dose units, 9 (29.0%) patients showed an actual adherence of <90%. Moreover, the actual adherence of 3 (9.7%) patients was <60%. Unexpectedly, 4 (12.9%) patients showed the actual adherence exceeding 100% (196%, 1 patient; 107-132%, 3 patients). CONCLUSIONS: We demonstrated a large difference between the self-reported and the actual adherence to treatment by counting the unused single-dose units of eyedrops. Preservative-free topical anti-glaucoma medications (formulated in single-dose units) provide clinicians an opportunity to assess the actual adherence of glaucoma patients by counting the unused units of eyedrops.

Key Words: Adherence;Dorzolamide/timolol fixed combination;Glaucoma;Single dose units