Timolol

Timolol
Timolol
Systematic (IUPAC) name
(S)-1-(tert-butylamino)-3-[(4-morpholin-4-yl-1,2,5-thiadiazol-3-yl)oxy]propan-2-ol
Clinical data
Trade names Timoptic
AHFS/Drugs.com monograph
MedlinePlus a602022
Pregnancy cat. C(AU) C(US)
Legal status ℞ Prescription only
Routes oral, Ophthalmic
Pharmacokinetic data
Bioavailability 60%
Metabolism Hepatic: 80%
Half-life 2.5-5 hours
Excretion Renal
Identifiers
CAS number 26839-75-8 YesY
ATC code C07AA06
PubChem CID 33624
IUPHAR ligand 565
DrugBank APRD00229
ChemSpider 31013 YesY
UNII 5JKY92S7BR YesY
KEGG D08600 YesY
ChEBI CHEBI:9599 YesY
ChEMBL CHEMBL499 YesY
Chemical data
Formula C13H24N4O3S 
Mol. mass 316.421 g/mol
SMILES eMolecules & PubChem
 N(what is this?)  (verify)

Timolol maleate is a non-selective beta-adrenergic receptor blocker.

Contents

Uses

In its oral form (Blocadren), it is used:

In its ophthalmic form (brand names Timoptol in Italy; Timoptic), 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.

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.

Usual dosage

  • Children and Adults: Ophthalmic: Initial: 0.25% solution, instill 1 drop twice daily; increase to 0.5% solution if response not adequate; decrease to 1 drop/day if *controlled; do not exceed 2 drops twice daily of 0.5% solution Adults: Oral:
  • Hypertension: Initial: 10 mg twice daily, increase gradually every 14 days, usual dosage: 20–40 mg/day in 2 divided doses; maximum: 60 mg/day
  • Prevention of myocardial infarction: 10 mg twice daily initiated within 1–6 weeks after infarction
  • Migraine headache: Initial: 10 mg twice daily, increase to maximum of 30 mg/day

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): 5 mg, 10 mg, 20 mg

For ophthalmic use, timolol is also available combined with other medications:

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.

Chemical synthesis

Timolol 2.png

References

  1. ^ Dawn A. Marcus; Philip A. Bain (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 9781603274388. http://books.google.com/books?id=Z5YWpjj89NEC&pg=PA141. Retrieved 14 November 2010. 

External links

v · d · eBeta blockers (C07)
Beta, nonselective
Alprenolol  • Bopindolol  • Bupranolol  • Carteolol  • Cloranolol  • Mepindolol  • Nadolol  • Oxprenolol  • Penbutolol  • Pindolol  • Propranolol  • Sotalol  • Tertatolol  • Timolol
Beta1 selective
Acebutolol  • Atenolol  • Betaxolol  • Bevantolol  • Bisoprolol  • Celiprolol  • Epanolol  • Esmolol  • Nebivolol  • Metoprolol  • Practolol  • S-atenolol  • Talinolol
Alpha + beta
Other/ungrouped

M: VAS

anat(a:h/u/t/a/l,v:h/u/t/a/l)/phys/devp/cell/prot

noco/syva/cong/lyvd/tumr, sysi/epon, injr

proc, drug(C2s+n/3/4/5/7/8/9)
v · d · eOphthalmologicals: antiglaucoma preparations and miotics (S01E)
Sympathomimetics
Parasympathomimetics
muscarinic
muscarinic/nicotinic
Carbonic anhydrase inhibitors/
(sulfonamides)
Beta blocking agents
Befunolol • Betaxolol • Carteolol • Levobunolol • Metipranolol • Timolol • Mepindolol
Prostaglandin analogues (F2α)
Bimatoprost • Latanoprost • Tafluprost • Travoprost • Unoprostone
Other agents

M: EYE

anat(g/a/p)/phys/devp/prot

noco/cong/tumr, epon

proc, drug(S1A/1E/1F/1L)


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