Timolol maleate is a non-selective beta-adrenergic receptor antagonist indicated for treating glaucoma, heart attacks, hypertension, and migraine headache.
It is on the World Health Organization's List of Essential Medicines, a list of the most important medications needed in a basic health system.
Medical uses
In its oral form, it is used:
- to treat high blood pressure
- to prevent heart attacks
- to prevent migraine headaches
In its ophthalmic form it is used to treat open-angle and occasionally secondary glaucoma by reducing aqueous humour production through blockage of the beta receptors on the ciliary epithelium. The pharmacological mechanism by which it actually does this is still unknown. First beta-blocker approved for topical use in treatment of glaucoma in the USA (1978). With monotherapy, depresses IOP 18-34% below baseline within first few treatments. However, there are short-term escape and long-term drift effects in some patients. That is, tolerance develops. May reduce extent of diurnal IOP curve up to 50%. IOP higher during sleep. 5-10x more potent beta-blocker than propranolol. Light sensitive; preserved with 0.01% benzalkonium Cl (and also comes BAC free). Can also be used in adjunctive therapy with pilocarpine or CAIs.
The 20 January 2014, issue of the Medical Journal of Australia (MJA) reported on topical timolol being successfully used to treat chronic leg ulcers in 92-year-old patient. <1>
A Cochrane Systematic Review compared the effect of timolol versus brimonidine in slowing the progression of open angle glaucoma in adult participants.
Side effects
The most serious possible side effects include cardiac arrhythmias and severe bronchospasms. Timolol can also lead to fainting, congestive heart failure, depression, confusion, worsening of Raynaud's syndrome and impotence.
Formulations
- Gel-forming solution, ophthalmic, as maleate (Timoptic-XE): 0.25% (2.5 mL, 5 mL); 0.5% (2.5 mL, 5 mL)
- Solution, ophthalmic, as hemihydrate (Betimol): 0.25% (5 mL, 10 mL, 15 mL); 0.5% (5 mL, 10 mL, 15 mL) [contains benzalkonium chloride]
- Solution, ophthalmic, as maleate: 0.25% (5 mL, 10 mL, 15 mL); 0.5% (5 mL, 10 mL, 15 mL) [contains benzalkonium chloride]
- Timoptic: 0.25% (5 mL, 10 mL); 0.5% (5 mL, 10 mL) [contains benzalkonium chloride]
- Solution, ophthalmic, as maleate [preservative free] (Timoptic OcuDose): 0.25% (0.2 mL);0.5% (0.2 mL) [single use]
- Tablet, as maleate (Blocadren): 5Â mg, 10Â mg, 20Â mg
For ophthalmic use, timolol is also available combined with other medications:
- Combigan - timolol and brimonidine
- IOTIM-B - timolol and brimonidine
- Cosopt - timolol maleate and dorzolamide hydrochloride
- DuoTrav - timolol and travoprost
- Xalacom (Pfizer) - timolol and latanoprost
Brand names
- In Canada: Apo-Timol, Apo-Timop, Gen-Timolol, Nu-Timolol, Phoxal-timolol, PMS-Timolol, Tim-AK, Timoptic, Timoptic-XE.
- In the United States: Betimol, Blocadren, Istalol, Timoptic, Timoptic-XE, Timoptic OcuDose.
- In Jordan:Apimol ( By API )
- IOTIM is No. 1 prescribed brand in INDIA from FDC LIMITED .
Chemical synthesis
References
External links
- http://dx.doi.org/10.1021/jo00881a011