Timolol
Chemical compound
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Clinical data | |
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Trade names | Betimol, Blocadren, Istalol, Timoptic, others [1] |
AHFS / Drugs.com |
Maleate
Monograph
eent Monograph |
MedlinePlus | a684029 |
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By mouth , topical ( eye drop ) |
Drug class | Beta blocker |
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Pharmacokinetic data | |
Bioavailability | 60% |
Metabolism | Liver (80%, mainly CYP2D6 [2] ) |
Onset of action | 15–30 min [3] |
Elimination half-life | 2.5–5 hours |
Duration of action | 24 hours [3] |
Excretion | Kidney |
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CompTox Dashboard ( EPA ) | |
ECHA InfoCard |
100.043.651
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Chemical and physical data | |
Formula | C 13 H 24 N 4 O 3 S |
Molar mass | 316.42 g·mol −1 |
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Timolol is a beta blocker medication used either by mouth or as eye drops . [3] [4] As eye drops it is used to treat increased pressure inside the eye such as in ocular hypertension and glaucoma . [3] By mouth it is used for high blood pressure , chest pain due to insufficient blood flow to the heart , to prevent further complications after a heart attack , and to prevent migraines . [4]
Common side effects with the drops is irritation of the eye. [3] Common side effects by mouth include tiredness, slow heart beat , itchiness, and shortness of breath . [4] Other side effects include masking the symptoms of low blood sugar in those with diabetes . [3] Use is not recommended in those with asthma , uncompensated heart failure , or COPD . [3] It is unclear if use during pregnancy is safe for the baby. [5] Timolol is a non-selective beta blocker . [3]
Timolol was patented in 1968, and came into medical use in 1978. [6] It is on the World Health Organization's List of Essential Medicines . [7] Timolol is available as a generic medication . [3] [8] In 2020, it was the 143rd most commonly prescribed medication in the United States, with more than 4 million prescriptions. [9] [10]
Medical uses
By mouth
In its by mouth or oral form, it is used:
- to treat high blood pressure
- to prevent heart attacks
- to prevent migraine headaches [11]
The combination of timolol and the alpha-1 blocker prazosin has sedative effects. [12]
Eye drops
In its eye drop form it is used to treat open-angle and, occasionally, secondary glaucoma . [3] [13] 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 first beta blocker approved for topical use in treatment of glaucoma in the United States (1978). [14] When used by itself, it depresses intraocular 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 diurnal IOP curve up to 50%. The IOP is higher during sleep. Efficacy of timolol in lowering IOP during the sleep period may be limited. [15] [16] [17] It is a 5–10× more potent β-blocker than propranolol . 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 with pilocarpine , carbonic anhydrase inhibitors [18] or prostaglandin analogs. [19]
A Cochrane review compared the effect of timolol versus brimonidine in slowing the progression of open angle glaucoma in adults but found insufficient evidence to come to conclusions. [20]
On the skin
In its gel form it is used on the skin to treat infantile hemangiomas . [21]
Contraindications
The medication should not be taken by individuals with: [22]
- An allergy to timolol or any other beta-blockers
- Asthma or severe chronic obstructive bronchitis
- A slow heart rate (bradycardia) , or a heart block
- Heart failure [23]
Side effects
The most serious possible side effects include cardiac arrhythmias and severe bronchospasms . [22] Timolol can also lead to fainting , congestive heart failure , depression , confusion , worsening of Raynaud's syndrome and impotence . [22]
Side effects when given in the eye include: burning sensation, eye redness, superficial punctate keratopathy, corneal numbness. [24] [13]
Formulations
It is available in tablet and liquid formulations. [22] [24]
For ophthalmic use, timolol is also available combined:
-
with
carbonic anhydrase inhibitors
:
- timolol and brinzolamide
- timolol and dorzolamide
- with α 2 agonists:
-
with
prostaglandin analogs
:
- timolol and latanoprost
- timolol and travoprost
Brand names
Timolol is marketed under many trade names worldwide. [1] Timolol eye drops are marketed under the brand name Istalol among others. [25] [26]
References
- 1 2 "Timolol" . Drugs.com . Archived from the original on 7 March 2016 . Retrieved 28 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 . PMID 17431033 . S2CID 794764 .
- 1 2 3 4 5 6 7 8 9 10 11 "Timolol eent" . The American Society of Health-System Pharmacists. Archived from the original on 28 December 2016 . Retrieved 8 December 2016 .
- 1 2 3 "Timolol Maleate" . The American Society of Health-System Pharmacists. Archived from the original on 28 December 2016 . Retrieved 8 December 2016 .
- ↑ "Timolol ophthalmic Use During Pregnancy" . The American Society of Health-System Pharmacists. Archived from the original on 28 December 2016 . Retrieved 28 December 2016 .
- ↑ Fischer J, Ganellin CR (2006). Analogue-based Drug Discovery . John Wiley & Sons. p. 460. ISBN 9783527607495 . Archived from the original on 28 December 2016.
- ↑ World Health Organization (2019). World Health Organization model list of essential medicines: 21st list 2019 . Geneva: World Health Organization. hdl : 10665/325771 . WHO/MVP/EMP/IAU/2019.06. License: CC BY-NC-SA 3.0 IGO.
- ↑ "Competitive Generic Therapy Approvals" . U.S. Food and Drug Administration (FDA) . 29 June 2023. Archived from the original on 29 June 2023 . Retrieved 29 June 2023 .
- ↑ "The Top 300 of 2020" . ClinCalc . Retrieved 7 October 2022 .
- ↑ "Timolol - Drug Usage Statistics" . ClinCalc . Retrieved 7 October 2022 .
- ↑ Marcus DA, Bain PA (27 February 2009). Effective Migraine Treatment in Pregnant and Lactating Women: A Practical Guide . シュプリンガー・ジャパン株式会社. pp. 141–. ISBN 978-1-60327-438-8 . Archived from the original on 5 November 2017 . Retrieved 14 November 2010 .
- ↑ Atkin T, Comai S, Gobbi G (April 2018). "Drugs for Insomnia beyond Benzodiazepines: Pharmacology, Clinical Applications, and Discovery" . Pharmacol Rev . 70 (2): 197–245. doi : 10.1124/pr.117.014381 . PMID 29487083 . S2CID 3578916 .
- 1 2 "Timolol Ophthalmic" . MedlinePlus . 15 April 2017 . Retrieved 31 December 2019 .
- ↑ Sambhara D, Aref AA (January 2014). "Glaucoma management: relative value and place in therapy of available drug treatments" . Therapeutic Advances in Chronic Disease . 5 (1): 30–43. doi : 10.1177/2040622313511286 . PMC 3871276 . PMID 24381726 .
- ↑ Liu JH, Kripke DF, Weinreb RN (September 2004). "Comparison of the nocturnal 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 . PMID 15364220 .
- ↑ 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 . PMID 19157559 .
- ↑ Liu JH, Slight JR, Vittitow JL, Scassellati Sforzolini B, Weinreb RN (September 2016). "Efficacy of Latanoprostene Bunod 0.024% Compared With Timolol 0.5% in Lowering Intraocular Pressure Over 24 Hours" . American Journal of Ophthalmology . 169 : 249–257. doi : 10.1016/j.ajo.2016.04.019 . PMID 27457257 .
- ↑ 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. PMID 9697378 .
- ↑ "Ganfort 0.3 mg/ml + 5 mg/ml eye drops, solution - Summary of Product Characteristics (SmPC)" . (emc) . 20 February 2020 . Retrieved 1 March 2020 .
- ↑ Sena DF, Lindsley K (January 2017). "Neuroprotection for treatment of glaucoma in adults" . The Cochrane Database of Systematic Reviews . 1 (1): CD006539. doi : 10.1002/14651858.CD006539.pub4 . PMC 5370094 . PMID 28122126 .
- ↑ Novoa M, Baselga E, Beltran S, Giraldo L, Shahbaz A, Pardo-Hernandez H, Arevalo-Rodriguez I (April 2018). "Interventions for infantile haemangiomas of the skin" . The Cochrane Database of Systematic Reviews . 2018 (4): CD006545. doi : 10.1002/14651858.CD006545.pub3 . PMC 6513200 . PMID 29667726 .
- 1 2 3 4 "Timolol Maleate tablet" . DailyMed . 17 August 2006 . Retrieved 1 December 2019 .
- ↑ "Package leaflet: Information for the user Timolol" (PDF) . hpra.ie .
- 1 2 "Betimol- timolol solution" . DailyMed . 18 March 2010 . Retrieved 1 December 2019 .
- ↑ "Generic Istalol Availability" . Drugs.com . Retrieved 20 June 2019 .
- ↑ "Istalol" . Drugs.com . 1 August 2018 . Retrieved 19 July 2019 .
External links
- "Timolol" . Drug Information Portal . U.S. National Library of Medicine.
- "Timolol Ophthalmic" . Drug Information Portal . U.S. National Library of Medicine.
- "Timolol maleate" . Drug Information Portal . U.S. National Library of Medicine.
- "Timolol Ophthalmic" . MedlinePlus .
Beta blockers
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