OBJECTIVES: Using intraocular pressure lowering agents (IOPLAs) is the major treatment approach for glaucoma. Prostaglandin analogs (PAs) are commonly used as first-line treatment; Patients on PAs may receive other IOPLAs as adjunctive therapy (AT). Treatment of systemic hypertension with oral antihypertensives (AHs) may affect intraocular pressure. We quantified the use of AT and AH in association with PAs. METHODS: We conducted a cohort study using claims data from Québec, Canada. We identified all patients with a first claim for PAs (bimatoprost, latanoprost or travoprost) between 05-24-03 and 02-28-05. AT and AH utilization were identified by at least two claims in the 12-month follow-up period from their first PA prescription. Statistical and descriptive analyses were performed using SAS 9.1. RESULTS: We included 10,618 patients (average age=74±10, 60% females). PA users naïve to IOPLA treatment comprised 60% of the cohort. Of that cohort, we identified 3813 patients who were not on statin therapy. Of those 3813 patients, 1135 were on PA only, 706 were on PA+AT, 1291 were on PA+AH, and 681 were on PA+AT+AH. Of the PA and non-AH users, 38% were on AT, and of the PA+AH users, 35% were on AT. There were significant differences among these groups (?2=5.988, p=0.014). The time to adjunct therapy for the PA+AT users was 165 days for the non-AH and 198 days for the AH groups, respectively, with statistically significance differences (Kruskal-Wallis Test, ?2=14.93, p<0.001). It was also determined that the PA+AT+AH users were significantly older than the PA+AT users (Kruskal-Wallis Test, ?2=101.47, p<0.001). CONCLUSION: Patients on PA using AHs required less AT therapy in the first 12 months of PA use, and started AT later than non-AH users. Further research is warranted for incident vs. prevalent analyses, to fully evaluate the impact of AH therapy on the ability to control IOP.