Product Information
Registration Status: ActiveSIN11643P
COSOPT OPHTHALMIC SOLUTION is approved to be sold in Singapore with effective from 2001-08-22. It is marketed by SANTEN PHARMACEUTICAL ASIA PTE LTD, with the registration number of SIN11643P.
This product contains Dorzolamide 2%, and Timolol 0.5% in the form of SOLUTION. It is approved for OPHTHALMIC use.
This product is manufactured by Santen Pharmaceutical Co. in JAPAN.
It is a Prescription Only Medicine that can only be obtained from a doctor or a dentist, or a pharmacist with a prescription from a Singapore-registered doctor or dentist.
Product Reference
Important Note: For generic product, the SPC/PIL provided may not be brand specific.
{{/items}} {{^items}}Description
Dorzolamide is a carbonic anhydrase (CA) inhibitor. It is used in ophthalmic solutions (Trusopt) to lower intraocular pressure (IOP) in open-angle glaucoma and ocular hypertension.
Indication
For the treatment of elevated intraocular pressure in patients with ocular hypertension or open-angle glaucoma. Also used prophylatically for the inhibition of perioperative IOP increase (before neodynium yttrium aluminum garnet laser posterior capsulotomy).
Mechanism of Action
Dorzolamide is a sulfonamide and a highly specific carbonic anhydrase II (CA-II) inhibitor, which is the main CA isoenzyme involved in aqueous humor secretion. Inhibition of CA-II in the ciliary processes of the eye decreases aqueous humor secretion, presumably by slowing the formation of bicarbonate ions with subsequent reduction in sodium and fluid transport. Dorzolamide also accumulates in red blood cells as a result of CA-II binding, as CA-II is found predominantly in erythrocytes. However, sufficient CA-II activity remains so that adverse effects due to systemic CA inhibition are not observed.
Toxicity
Dizziness, headache, shortness of breath, slow heartbeat, severe asthma, cardiac arrest
Active Ingredient/Synonyms
(4S-trans)-4-(ETHYLAMINO)-5,6-dihydro-6-methyl-4H-thieno(2,3-b)thiopyran-2-sulfonamide-7,7-dioxide | (4S,6S)-4-Ethylamino-6-methyl-7,7-dioxo-4,5,6,7-tetrahydro-7lambda*6*-thieno[2,3-b]thiopyran-2-sulfonic acid amide | (4S,trans)-4-(Ethylamino)-6-methyl-5,6-dihydro-4H-thieno[2,3-b]thiopyran-2-sulfonamide 7,7-dioxide | 4-Ethylamino-6-methyl-7,7-dioxo-4,5,6,7-tetrahydro-7lambda*6*-thieno[2,3-b]thiopyran-2-sulfonic acid amide | 4-Ethylamino-6-methyl-7,7-dioxo-4,5,6,7-tetrahydro-7lambda6-thieno[2,3-b]thiopyran-2-sulfonic acid amide | 4S,6S-Dorzolamide | Dorzolamid | Dorzolamida | Dorzolamide | Dorzolamidum | Dorzolamide |
Source of information: Drugbank (External Link). Last updated on: 3rd July 18. *Trade Name used in the content below may not be the same as the HSA-registered product.
Description
A beta-adrenergic antagonist similar in action to propranolol. The levo-isomer is the more active. Timolol has been proposed as an antihypertensive, antiarrhythmic, antiangina, and antiglaucoma agent. It is also used in the treatment of migraine disorders and tremor. [PubChem]
Indication
In its oral form it is used to treat high blood pressure and prevent heart attacks, and occasionally to prevent migraine headaches. In its opthalmic form it is used to treat open-angle and occasionally secondary glaucoma.
Mechanism of Action
Like propranolol and nadolol, timolol competes with adrenergic neurotransmitters such as catecholamines for binding at beta(1)-adrenergic receptors in the heart and vascular smooth muscle and beta(2)-receptors in the bronchial and vascular smooth muscle. Beta(1)-receptor blockade results in a decrease in resting and exercise heart rate and cardiac output, a decrease in both systolic and diastolic blood pressure, and, possibly, a reduction in reflex orthostatic hypotension. Beta(2)-blockade results in an increase in peripheral vascular resistance. The exact mechanism whereby timolol reduces ocular pressure is still not known. The most likely action is by decreasing the secretion of aqueous humor.
Pharmacokinetics
- Absorption
- Bioavailability is about 60%
- Distribution
- Metabolism
- Primarily hepatic (80%) via the cytochrome P450 2D6 isoenzyme.
- Elimination
Toxicity
LD50=1190 mg/kg (oral, mice), LD50=900 mg/kg (oral, rat). Symptoms of overdose include drowsiness, vertigo, headache, and atriventricular block.
Active Ingredient/Synonyms
(S)-1-(tert-butylamino)-3-[(4-morpholin-4-yl-1,2,5-thiadiazol-3-yl)oxy]propan-2-ol | Timolol | Timolol anhydrous | Timololo | Timololum | Timolol |
Source of information: Drugbank (External Link). Last updated on: 3rd July 18. *Trade Name used in the content below may not be the same as the HSA-registered product.