RESUMO
BACKGROUND: The prevalence of open angle glaucoma increases with age, with many patients also receiving medications for non-ocular systemic diseases. Little is known about how systemic medications impact on the need for adjunctive therapy with prostaglandin analogues (PGA). OBJECTIVES: To evaluate whether systemic medications for hypertension, cholesterol, or glucose influence the need for adjunctive intraocular pressure (IOP) lowering medications in patients using PGAs. METHODS: Pharmaceutical records from the Québec prescription database provided a sample of patients receiving prescriptions for bimatoprost, latanoprost, or travoprost, from which subjects receiving > or =1 prescription for antihypertensives, antidiabetics. diuretics, and statins were identified. Chi-square tests compared proportions using PGAs to those using PGAs + adjunctive therapy, based on the use or non-use of systemic medications; a logistic regression was performed post hoc to adjust for gender and age. RESULTS: Of the 8548 evaluated patients (all using PGAs); 2934 (34.3%) took none of the studied systemic drugs. For the 5614 patients taking systemic medications, significantly fewer (p < 0.001) required an additional IOP lowering medication if taking a systemic antihypertensive medication. The use of a statin or a diabetic medication, alone or in combination, in addition to a PGA, made no significant difference in the need for adjunct glaucoma therapy. Individual drugs associated with significantly less utilization of adjunctive glaucoma medications were calcium-channel blockers, angiotensin-converting enzyme (ACE), and combination antihypertensive therapies. DISCUSSION: A profound association between systemic antihypertensive use and a reduced need for adjunct topical IOP lowering medications in patients using the same prostaglandin analogue for at least one year was found. LIMITATIONS: The use of a prescription claims database without patient compliance or patient outcomes may not reflect actual patient medication use. In addition, these findings may not be applicable to all patients initiating prostaglandin analogues. CONCLUSIONS: In this real-world population-based evaluation, a significant association exists between using systemic antihypertensive medications and reduced use of adjunctive IOP lowering therapies. These results confirm findings from previous studies suggesting an IOP lowering effect with systemic agents or some synergy with topical therapies.
