Objective evaluation of adjunctive glaucoma therapy

Abstract

Abstract Purpose: To measure adherence with electronic monitoring in two populations of subjects: those using once‐daily prostaglandin analogs (q.d.), and those on adjunctive medicine to the prostaglandin analog. Methods: Single‐site, open‐label, non‐randomized, parallel, 60 day study. 62 open angle glaucoma or ocular hypertension adult subjects currently using either a topical prostaglandin as sole ocular hypotensive medical therapy q.d. (“1‐drug” subjects, n=31) or a topical prostaglandin plus an adjunctive topical ocular hypotensive product either q.d., twice‐daily (b.i.d.), or three‐times‐daily (t.i.d.) in the same eye(s) (“2‐drug” subjects, n = 31). An electronic event medication monitoring device was used to record each opening of the bottle containing the ocular hypotensive medication. The main outcome measures were dosing errors (number of under or over‐adherence events) and coverage (proportion of pharmacological duration covered by dosing) relative to ophthalmologist‐prescribed regimen. Results: Adherence to the prostaglandins q.d. was good in both groups by all measures (≤10% of subjects with >5 dosing errors and mean coverage of 97.2±6.1%). Adherence to the second medication in the 2‐drug group was poorer (37% of subjects with > 5 dosing errors and mean coverage of 85.6 ± 12.6%). For the subjects on β‐adrenoceptor antagonists, 24.8±18.4% of doses were taken at less than 10 hour intervals (over‐adherence). Conclusions: The use of electronic monitoring provides more information than simple “pill count,” bottle weighing methods, or prescription refill rate, as it incorporates a time component. We found that more complex dosing regimens result in poorer adherence, although q.d. drugs in a complex dosing regimen were found to have good adherence.