Timolol and metoprolol. A diurnal study of the ocular and systemic effects in glaucoma patients.

A comparison of the diurnal effects of timolol 0.5% and metoprolol 3.0% eye drops on the intraocular pressure, blood pressure and heart rate in 10 glaucoma patients was performed in a double-masked cross-over study. Both agents produced a significant ocular hypotensive effect for more than 12 h. Timolol appeared to be more potent after 4 and 7 h. No significant difference in hypotensive action was present between timolol and metoprolol 1, 12 and 24 h after treatment. The mean arterial pressure was significantly lowered after I and 4 h with timolol and after 1 h during metoprolol therapy. Both agents reduced the heart rate after 1 h. Measurements of plasma concentration of ocular applied timolol and metoprolol showed in 4 patients levels of plasma timolol high enough to induce minimal systemic beta-blockade.