Clinical data | |
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Trade names | Betimol, Blocadren, Istalol, Timoptic, others [1] |
AHFS/ Drugs.com | Maleate
Monograph eent Monograph |
MedlinePlus | a684029 |
License data | |
Pregnancy category |
|
Routes of administration | By mouth, topical ( eye drop) |
Drug class | Beta blocker |
ATC code | |
Legal status | |
Legal status | |
Pharmacokinetic data | |
Bioavailability | 60% |
Metabolism | Liver (80%, mainly CYP2D6 [4]) |
Onset of action | 15–30 min [3] |
Elimination half-life | 2.5–5 hours |
Duration of action | 24 hours [3] |
Excretion | Kidney |
Identifiers | |
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CAS Number | |
PubChem CID | |
IUPHAR/BPS | |
DrugBank | |
ChemSpider | |
UNII | |
KEGG | |
ChEBI | |
ChEMBL | |
CompTox Dashboard ( EPA) | |
ECHA InfoCard | 100.043.651 |
Chemical and physical data | |
Formula | C13H24N4O3S |
Molar mass | 316.42 g·mol−1 |
3D model ( JSmol) | |
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(verify) |
Timolol is a beta blocker medication used either by mouth or as eye drops. [3] [5] 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. [5]
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. [5] 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 fetus. [6] Timolol is a non-selective beta blocker. [3]
Timolol was patented in 1968, and came into medical use in 1978. [7] It is on the World Health Organization's List of Essential Medicines. [8] Timolol is available as a generic medication. [3] [9] In 2021, it was the 163rd most commonly prescribed medication in the United States, with more than 3 million prescriptions. [10] [11]
In its by mouth or oral form, it is used:
The combination of timolol and the alpha-1 blocker prazosin has sedative effects. [13]
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 first beta blocker approved for topical use in treatment of glaucoma in the United States (1978). [15] 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 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 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 [19] or prostaglandin analogs. [20]
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. [21]
In its gel form it is used on the skin to treat infantile hemangiomas. [22]
The medication should not be taken by individuals with: [23]
The most serious possible side effects include cardiac arrhythmias and severe bronchospasms. [23] Timolol can also lead to fainting, congestive heart failure, depression, confusion, worsening of Raynaud's syndrome and impotence. [23]
Side effects when given in the eye include: burning sensation, eye redness, superficial punctate keratopathy, corneal numbness. [25] [14]
It is available in tablet and liquid formulations. [23] [25]
For ophthalmic use, timolol is also available combined:
Timolol is marketed under many trade names worldwide. [1] Timolol eye drops are marketed under the brand name Istalol among others. [26] [27]
Clinical data | |
---|---|
Trade names | Betimol, Blocadren, Istalol, Timoptic, others [1] |
AHFS/ Drugs.com | Maleate
Monograph eent Monograph |
MedlinePlus | a684029 |
License data | |
Pregnancy category |
|
Routes of administration | By mouth, topical ( eye drop) |
Drug class | Beta blocker |
ATC code | |
Legal status | |
Legal status | |
Pharmacokinetic data | |
Bioavailability | 60% |
Metabolism | Liver (80%, mainly CYP2D6 [4]) |
Onset of action | 15–30 min [3] |
Elimination half-life | 2.5–5 hours |
Duration of action | 24 hours [3] |
Excretion | Kidney |
Identifiers | |
| |
CAS Number | |
PubChem CID | |
IUPHAR/BPS | |
DrugBank | |
ChemSpider | |
UNII | |
KEGG | |
ChEBI | |
ChEMBL | |
CompTox Dashboard ( EPA) | |
ECHA InfoCard | 100.043.651 |
Chemical and physical data | |
Formula | C13H24N4O3S |
Molar mass | 316.42 g·mol−1 |
3D model ( JSmol) | |
| |
| |
(verify) |
Timolol is a beta blocker medication used either by mouth or as eye drops. [3] [5] 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. [5]
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. [5] 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 fetus. [6] Timolol is a non-selective beta blocker. [3]
Timolol was patented in 1968, and came into medical use in 1978. [7] It is on the World Health Organization's List of Essential Medicines. [8] Timolol is available as a generic medication. [3] [9] In 2021, it was the 163rd most commonly prescribed medication in the United States, with more than 3 million prescriptions. [10] [11]
In its by mouth or oral form, it is used:
The combination of timolol and the alpha-1 blocker prazosin has sedative effects. [13]
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 first beta blocker approved for topical use in treatment of glaucoma in the United States (1978). [15] 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 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 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 [19] or prostaglandin analogs. [20]
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. [21]
In its gel form it is used on the skin to treat infantile hemangiomas. [22]
The medication should not be taken by individuals with: [23]
The most serious possible side effects include cardiac arrhythmias and severe bronchospasms. [23] Timolol can also lead to fainting, congestive heart failure, depression, confusion, worsening of Raynaud's syndrome and impotence. [23]
Side effects when given in the eye include: burning sensation, eye redness, superficial punctate keratopathy, corneal numbness. [25] [14]
It is available in tablet and liquid formulations. [23] [25]
For ophthalmic use, timolol is also available combined:
Timolol is marketed under many trade names worldwide. [1] Timolol eye drops are marketed under the brand name Istalol among others. [26] [27]