In its eye drop form it is used to treat open-angle and, occasionally,secondary glaucoma.[3][14] The mechanism of action of timolol is probably the reduction of the formation of aqueous humor[3] in the ciliary body in the eye. It was the firstbeta blocker approved for topical use in treatment of glaucoma in the United States (1978).[15] When used by itself, it depressesintraocular pressure (IOP) 18–34% below baseline within first few treatments. However, there are short-term escape and long-term drift effects in some people. That is, tolerance develops. It may reduce the extent of the daytime IOP curve up to 50%. The IOP is higher during sleep. Efficacy of timolol in lowering IOP during the sleep period may be limited.[16][17][18] It is a 5–10× more potent beta blocker thanpropranolol. Timolol is light-sensitive; it is usually preserved with 0.01%benzalkonium chloride (BAC), but also comes BAC-free. It can also be used in combination withpilocarpine,carbonic anhydrase inhibitors[19] orprostaglandin analogs.[20]
ACochrane review compared the effect of timolol versusbrimonidine in slowing the progression of open angle glaucoma in adults but found insufficient evidence to come to conclusions.[21]
^abcdefghijk"Timolol eent". The American Society of Health-System Pharmacists.Archived from the original on 28 December 2016. Retrieved8 December 2016.
^Volotinen M, Turpeinen M, Tolonen A, Uusitalo J, Mäenpää J, Pelkonen O (July 2007). "Timolol metabolism in human liver microsomes is mediated principally by CYP2D6".Drug Metabolism and Disposition.35 (7):1135–1141.doi:10.1124/dmd.106.012906.PMID17431033.S2CID794764.
^abc"Timolol Maleate". The American Society of Health-System Pharmacists.Archived from the original on 28 December 2016. Retrieved8 December 2016.
^The selection and use of essential medicines 2023: web annex A: World Health Organization model list of essential medicines: 23rd list (2023). Geneva:World Health Organization. 2023.hdl:10665/371090. WHO/MHP/HPS/EML/2023.02.
^Liu JH, Kripke DF, Weinreb RN (September 2004). "Comparison of the nighttime effects of once-daily timolol and latanoprost on intraocular pressure".American Journal of Ophthalmology.138 (3):389–95.doi:10.1016/j.ajo.2004.04.022.PMID15364220.
^Liu JH, Medeiros FA, Slight JR, Weinreb RN (March 2009). "Comparing diurnal and nocturnal effects of brinzolamide and timolol on intraocular pressure in patients receiving latanoprost monotherapy".Ophthalmology.116 (3):449–54.doi:10.1016/j.ophtha.2008.09.054.PMID19157559.
^Strohmaier K, Snyder E, Adamsons I (July 1998). "A multicenter study comparing dorzolamide and pilocarpine as adjunctive therapy to timolol: patient preference and impact on daily life".Journal of the American Optometric Association.69 (7):441–51.PMID9697378.
