The effects of separate and combined topical treatment with timolol maleate and trifluormethazolamide on the intraocular pressure in normal rabbits.
The effects of separate and combined topical treatment with timolol maleate and trifluormethazolamide (TFM) on the intraocular pressure (IOP) were studied in normotensive rabbits. Timolol had a distinct, albeit small, dose related hypotensive effect. Unilateral application of timolol resulted in dose related decrease in IOP in the untreated fellow eye. These effects could be observed only by using a protocol that reduces the contribution of individual and diurnal variations to the overall variability in IOP in the rabbit. Topical treatment with TFM caused a reduction in the calculated outflow pressure of 32%, similar to that observed after systemic administration of acetazolamide and methazolamide. At the concentration and dosage employed here there was no significant difference between the hypotensive effects of timolol and TFM. The maximal decrease in the calculated outflow pressure for the different doses of timolol varied between 24% to 37%. The hypotensive effect of the combined timolol and TFM treatment (delta IOP = -2.4 +/- 0.4 mmHg, n = 12) was greater than that observed in rabbits treated with TFM alone (delta IOP = -1.6 +/- 0.5 mmHg, n = 12). The increment was smaller than the initial effect of either drug alone.
D000287:Administration, Topical; D000818:Animals; D002940:Circadian Rhythm; D004357:Drug Synergism; D005901:Glaucoma / Q000188:drug therapy; D006801:Humans; D007429:Intraocular Pressure / Q000187:drug effects*; D008297:Male; D008704:Methazolamide / Q000008:administration & dosage* / Q000031:analogs & derivatives; D011817:Rabbits; D013830:Thiadiazoles / Q000008:administration & dosage*; D013999:Timolol / Q000008:administration & dosage*
D013830:Thiadiazoles; C037168:2,2,2-trifluoromethazolamide; D013999:Timolol; D008704:Methazolamide