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(timolol) Ophthalmic Solution
Betimol® (timolol ophthalmic solution), 0.25% and 0.5%, is a non-selective beta-adrenergic antagonist for ophthalmic use. The chemical name of the active ingredient is (S)-1-[(1,1-dimethylethyl)amino]-3-[[4-(4-morpholinyl)-1,2,5-thiadiazol-3-yl]oxy]-2-propanol. Timolol hemihydrate is the levo isomer. Specific rotation is [α]25 405nm=-16° (C=10% as the hemihydrate form in 1N HCI).
The molecular formula of timolol is Formula C13H24N4O3S and its structural formula is:
Timolol (as the hemihydrate) is a white, odorless, crystalline powder which is slightly soluble in water and freely soluble in ethanol. Timolol hemihy-drate is stable at room temperature.
Betimol® (timolol ophthalmic solution) is a clear, colorless, isotonic, sterile, microbiologically preserved phosphate buffered aqueous solution. It is supplied in two dosage strengths, 0.25% and 0.5%.
Each mL of Betimol® 0.25% contains 2.56 mg of timolol hemihydrate equivalent to 2.5 mg timolol.
Each mL of Betimol® 0.5% contains 5.12 mg of timolol hemihydrate equivalent to 5.0 mg timolol.
Inactive ingredients: monosodium and disodium phosphate dihydrate to adjust pH (6.5 - 7.5) and water for injection, benzalkonium chloride 0.01% added as preservative.
The osmolality of Betimol® (timolol ophthalmic solution) is 260 to 320 mOsmol/kg.
What are the possible side effects of timolol ophthalmic?
Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.
Stop using this medication and call your doctor at once if you have any of these serious side effects:
- swelling or redness of your eyelids;
- eye redness, discomfort, or sensitivity to light;
- drainage, crusting, or oozing of your eyes or eyelids;
- depressed mood, confusion, hallucinations, unusual thoughts or behavior;
- wheezing, gasping, or other breathing problems;
What are the precautions when taking timolol ophthalmic solution (Betimol)?
Before using timolol, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients (such as preservatives like benzalkonium chloride), which can cause allergic reactions or other problems. Talk to your pharmacist for more details.
This medication should not be used if you have certain medical conditions. Before using this medicine, consult your doctor or pharmacist if you have: lung disease (e.g., current or past history of asthma, severe chronic obstructive pulmonary disease), certain types of irregular heartbeats (e.g., sinus bradycardia, second or third degree AV block), certain types of heart disease (e.g., severe heart failure, cardiogenic shock).
Before using this medication, tell your...
Last reviewed on RxList: 3/26/2009
This monograph has been modified to include the generic and brand name in many instances.
Additional Betimol Information
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You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
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