EVALUATION OF MULTIPLE DOSES OF 4 AND 6-PERCENT TIMOLOL, AND TIMOLOL COMBINED WITH 2-PERCENT PILOCARPINE IN CLINICALLY NORMAL BEAGLES AND BEAGLES WITH GLAUCOMA

Topically applied 4% timolol, 4% timolol combined with 2% pilocarpine, 6% timolol, and 6% timolol combined with 2% pilocarpine were evaluate d in clinically normal Beagles and Beagles with glaucoma. The drugs we re instilled twice daily for 5 days. Changes in intraocular pressure ( IOP), pupil size, and heart rate were recorded on days 1, 3, and 5 at 0, 2, 5, and 8 hours, starting at 8:30 AM. In clinically normal dogs, 4 and 6% topically administered timolol did not cause consistent reduc tions in IOP; however, with addition of 2% pilocarpine, IOP was consis tently lower. In the Beagles with glaucoma, 4 and 6% timolol and, to a greater extent, 4 and 6% timolol combined with 2% pilocarpine lowered IOP. The combinations lowered IOP and reduced pupil size consistently . In all test groups, either 4 or 6% topically applied timolol caused approximately 10% decrease in mean heart rate.