The Cardio-Vascular Effects Of Topical Timolol, Levobunolol And Betaxolol In Patients Of Chronic Simple Glaucoma
Dr Rashmi Sharma, 216-A,
Last-Morh Gandhi- Nagar Jammu Tawi.
Pin: 180004. J&K state (INDIA)
Background: βâ€“adrenergic antagonists are the most commonly prescribed drugs for glaucoma. However, these drugs can be absorbed into the systemic circulation through the naso-lacrimal duct to produce various systemic side effects.
Aims: The present study was conducted to evaluate the effects of topical timolol, levobunolol and betaxolol on the cardiovascular system in Indian patients of chronic simple glaucoma.
Settings And Design: This prospective randomized single-blind parallel study was conducted in the Department of Pharmacology and Therapeutics in collaboration with the Department of Ophthalmology of a teaching institute.
Methods And Material: Forty newly diagnosed patients of chronic simple glaucoma were included in the study. 16 patients (23 eyes), 12 patients (19 eyes) and 12 patients (20 eyes) were randomized to receive 0.5% timolol maleate, 0.5% levobunolol hydrochloride and 0.5% betaxolol hydrochloride respectively, as one drop twice a day instillation for 12 weeks. Blood pressure, pulse rate and intraocular pressure of each patient were recorded at 0, 6 and 12 weeks.
Statistics: Effects of the individual drug on various study parameters were analysed using the paired tâ€“test. P values <0.05 were taken as significant. A comparative analysis of the effects of the three drugs on the above parameters was done by using the analysis of variance test. Inter-group comparison was done using the Turkey test.
Results: Topical timolol, levobunolol and betaxolol lowered IOP by 13.05 Â± 1.53, 14.05 Â±1.47 and 7.58 Â± 0.90 mm of Hg respectively, at 6 weeks and by 16.12Â±1.67, 16.28 Â±1.85 and 8.53Â±0.98 respectively, at 12 weeks (P<0.001) .Both topical timolol and levobunolol produced more reduction in IOP than topical betaxolol, with P-values of 0.004 and 0.002 at 6 and 12 weeks respectively. All the three drugs produced a statistically significant reduction in the pulse rate and systolic and diastolic blood pressure, indicating the systemic absorption of β-blockers in a concentration enough to alter the cardiovascular parameters of the patients .On comparative analysis using analysis of variance, a statistically insignificant difference for change in the three parameters was observed among the three groups .
Conclusion: The results of our study necessitate an urgent need for ophthalmological physicians to exclude all the possible cardiovascular problems in the patients before prescribing a topical β-blocker.