istalol
Istalol (Timolol Maleate) is a beta-adrenergic blocker used to treat Angina Pectoris, Open-Angle Glaucoma, Heart Failure, Hypertension.
Timolol Maleate · by Bausch and Lomb
Available as a generic: Timolol Maleate
Key facts
- Active ingredient
- Timolol Maleate
- Drug class
- Beta-Adrenergic Blocker
- Form
- Drops
- Strength
- Timolol Maleate EQ 0.5% Base
- Type
- Prescription (Rx)
- Brand or generic
- Brand-name
- May treat
- angina pectoris, open-angle glaucoma, heart failure
- Manufacturer
- Bausch and Lomb
- What the pharmacy pays
- ~$1.06 per ml — not your price
- FDA application
- NDA021516
What is Istalol?
From the FDA label:ISTALOL (timolol maleate ophthalmic solution) 0.5% is a non-selective beta-adrenergic receptor blocking agent for topical ophthalmic use. Its chemical name is (-)-1-( tert -butylamino)-3-[(4-morpholino-1,2,5-thiadiazol-3-yl)oxy]-2-propanol maleate (1:1) (salt). Timolol maleate possesses an asymmetric carbon atom in its structure and is provided as the levo-isomer. Its molecular formula is C 13 H 24 N 4 O 3 S-C 4 H 4 O 4 and its structural formula is: Timolol maleate has a molecular weight of 432.49. It is a white, odorless, crystalline powder which is soluble in water, methanol, and alcohol. ISTALOL is stable at room temperature. ISTALOL ophthalmic solution is supplied as a sterile, isotonic, buffered, aqueous solution of timolol maleate in a single strength. It has a pH of 6.5-7.5 and an osmolality of 275-330 mOsm/kg. Each mL of ISTALOL contains the active ingredient 5 mg of timolol (6.8 mg of timolol maleate) with the inactive ingredients benzalkonium chloride (0.05 mg/mL), monobasic sodium phosphate monohydrate, potassium sorbate 0.47%, sodium chloride, sodium hydroxide, and purified water. chemstructure
How to use
One drop of ISTALOL should be administered in the affected eye(s) once a day in the morning (AM). If more than one topical ophthalmic drug is being used, the drugs should be administered at least five minutes apart. One drop in the affected eye(s) once a day in the morning. ( 2 )
Side effects
The most frequently reported adverse reactions have been burning and stinging upon instillation in 38% of patients treated with ISTALOL. Additional reactions reported with ISTALOL at a frequency of 4% to 10% include: blurred vision, cataract, conjunctival injection, headache, hypertension, infection, itching and decreased visual acuity. ( 6 ) To report SUSPECTED ADVERSE REACTIONS, contact Bausch & Lomb Incorporated at 1-800-553-5340 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. The most frequently reported adverse reactions have been burning and stinging upon instillation in 38% of patients treated with ISTALOL. Additional reactions reported with ISTALOL at a frequency of 4% to 10% include: blurred vision, cataract, conjunctival injection, headache, hypertension, infection, itching and decreased visual acuity. The following additional adverse reactions have been reported less frequently with ocular administration of this or other timolol maleate formulations. Timolol (Ocular Administration) Body as a Whole: Asthenia/fatigue and chest pain; Cardiovascular: Bradycardia, arrhythmia,…
Warnings
Important safety information
Potentiation of Respiratory Reactions Including Asthma ( 5.1 ) Cardiac Failure ( 5.2 ) Obstructive Pulmonary Disease ( 5.3 ) Increased Reactivity to Allergens ( 5.4 ) Potentiation of Muscle Weakness ( 5.5 ) Masking of Hypoglycemic Symptoms in Patients with Diabetes Mellitus ( 5.6 ) Masking of Thyrotoxicosis ( 5.7 ) 5.1 Potentiation of Respiratory Reactions Including Asthma ISTALOL contains timolol maleate; and although administered topically, it can be absorbed systemically. Therefore, the same adverse reactions found with systemic administration of beta-adrenergic blocking agents may occur with topical administration. For example, severe respiratory reactions and cardiac reactions including death due to bronchospasm in patients with asthma, and rarely death in association with cardiac failure, have been reported following systemic or ophthalmic administration of timolol maleate [see Contraindications ( 4.1 )]. 5.2 Cardiac Failure Sympathetic stimulation may be essential for support of the circulation in individuals with diminished myocardial contractility, and its inhibition of beta-adrenergic receptor blockade may precipitate more severe failure. In patients without a history of cardiac failure, continued depression of the myocardium with beta-blocking agents over a period of time can, in some cases, lead to cardiac failure. At the first sign or symptom of cardiac failure, ISTALOL should be discontinued [see Contraindications ( 4.2 )]. 5.3 Obstructive Pulmonary Disease Patients with chronic obstructive pulmonary disease (e.g., chronic bronchitis, emphysema) of mild or moderate severity, bronchospastic disease, or a history of bronchospastic disease [other than bronchial asthma or a history of bronchial asthma in which ISTALOL is contraindicated] should, in general, not receive beta-blocking agents, including ISTALOL [see Contraindications ( 4.1 )]. 5.4 Increased Reactivity to Allergens While taking beta-blockers, patients with a history of atopy or a history of severe anaphylactic reactions to a variety of allergens may be more reactive to repeated accidental, diagnostic, or therapeutic challenge with such allergens. Such patients may be unresponsive to the usual doses of epinephrine used to treat anaphylactic reactions. 5.5 Potentiation of Muscle Weakness Beta-adrenergic blockade has been reported to potentiate muscle weakness consistent with certain myasthenic symptoms (e.g., diplopia, ptosis, and generalized weakness). Timolol has been reported rarely to increase muscle weakness in some patients with myasthenia gravis or myasthenic symptoms. 5.6 Masking of Hypoglycemic Symptoms in Patients with Diabetes Mellitus Beta-adrenergic blocking agents should be administered with caution in patients subject to spontaneous hypoglycemia or to diabetic patients (especially those with labile diabetes) who are receiving insulin or oral hypoglycemic agents. Beta-adrenergic receptor blocking agents may mask the signs and symptoms of acute hypoglycemia. 5.7 Masking of Thyrotoxicosis Beta-adrenergic blocking agents may mask certain clinical signs (e.g., tachycardia) of hyperthyroidism. Patients suspected of developing thyrotoxicosis should be managed carefully to avoid abrupt withdrawal of beta-adrenergic blocking agents that might precipitate a thyroid storm. 5.8 Contamination of Topical Ophthalmic Products After Use There have been reports of bacterial keratitis associated with the use of multiple-dose containers of topical ophthalmic products. These containers had been inadvertently contaminated by patients who, in most cases, had a concurrent corneal disease or a disruption of the ocular epithelial surface [see Patient Counseling Information ( 17 )]. 5.9 Impairment of Beta-adrenergically Mediated Reflexes During Surgery The necessity or desirability of withdrawal of beta-adrenergic blocking agents prior to major surgery is controversial. Beta-adrenergic receptor blockade impairs the ability of the heart to respond to beta-adrenergically mediated reflex stimuli. This may augment the risk of general anesthesia in surgical procedures. Some patients receiving beta-adrenergic receptor blocking agents have experienced protracted severe hypotension during anesthesia. Difficulty in restarting and maintaining the heartbeat has also been reported. For these reasons, in patients undergoing elective surgery, some authorities recommend gradual withdrawal of beta-adrenergic receptor blocking agents. If necessary during surgery, the effects of beta-adrenergic blocking agents may be reversed by sufficient doses of adrenergic agonists. 5.10 Angle-Closure Glaucoma In patients with angle-closure glaucoma, the immediate objective of treatment is to reopen the angle. This may require constricting the pupil. Timolol maleate has little or no effect on the pupil. ISTALOL should not be used alone in the treatment of angle-closure glaucoma. 5.11 Cerebrovascular Insufficiency Because of potential effects of beta-adrenergic blocking agents on blood pressure and pulse, these agents should be used with caution in patients with cerebrovascular insufficiency. If signs or symptoms suggesting reduced cerebral blood flow develop following initiation of therapy with ISTALOL, alternative therapy should be considered. 5.12 Choroidal Detachment Choroidal detachment after filtration procedures has been reported with the administration of aqueous suppressant therapy (e.g., timolol). 5.13 Contact Lens Use ISTALOL contains benzalkonium chloride, an anti-microbial preservative which may be absorbed by soft contact lenses. Contact lenses should be removed prior to administration of the solution. Lenses may be reinserted 15 minutes following ISTALOL administration. 5.1 Potentiation of Respiratory Reactions Including Asthma ISTALOL contains timolol maleate; and although administered topically, it can be absorbed systemically. Therefore, the same adverse reactions found with systemic administration of beta-adrenergic blocking agents may occur with topical administration. For example, severe respiratory reactions and cardiac reactions including death due to bronchospasm in patients with asthma, and rarely death in association with cardiac failure, have been reported following systemic or ophthalmic administration of timolol maleate [see Contraindications ( 4.1 )]. 5.2 Cardiac Failure Sympathetic stimulation may be essential for support of the circulation in individuals with diminished myocardial contractility, and its inhibition of beta-adrenergic receptor blockade may precipitate more severe failure. In patients without a history of cardiac failure, continued depression of the myocardium with beta-blocking agents over a period of time can, in some cases, lead to cardiac failure. At the first sign or symptom of cardiac failure, ISTALOL should be discontinued [see Contraindications ( 4.2 )]. 5.3 Obstructive Pulmonary Disease Patients with chronic obstructive pulmonary disease (e.g., chronic bronchitis, emphysema) of mild or moderate severity, bronchospastic disease, or a history of bronchospastic disease [other than bronchial asthma or a history of bronchial asthma in which ISTALOL is contraindicated] should, in general, not receive beta-blocking agents, including ISTALOL [see Contraindications ( 4.1 )]. 5.4 Increased Reactivity to Allergens While taking beta-blockers, patients with a history of atopy or a history of severe anaphylactic reactions to a variety of allergens may be more reactive to repeated accidental, diagnostic, or therapeutic challenge with such allergens. Such patients may be unresponsive to the usual doses of epinephrine used to treat anaphylactic reactions. 5.5 Potentiation of Muscle Weakness Beta-adrenergic blockade has been reported to potentiate muscle weakness consistent with certain myasthenic symptoms (e.g., diplopia, ptosis, and generalized weakness). Timolol has been reported rarely to increase muscle weakness in some patients with myasthenia gravis or myasthenic symptoms. 5.6…
Who should not take Istalol
Bronchial asthma, a history of bronchial asthma, severe chronic obstructive pulmonary disease ( 4.1 , 5.1 , 5.3 ) Sinus bradycardia, second or third degree atrioventricular block, overt cardiac failure, cardiogenic shock ( 4.2 , 5.2 ) Hypersensitivity to any component of this product ( 4.3 ) 4.1 Asthma, COPD ISTALOL is contraindicated in patients with bronchial asthma; a history of bronchial asthma; severe chronic obstructive pulmonary disease [see Warnings and Precautions ( 5.1 , 5.3 )] . 4.2 Sinus Bradycardia, AV Block, Cardiac Failure, Cardiogenic Shock ISTALOL is contraindicated in patients with sinus bradycardia; second or third degree atrioventricular block; overt cardiac failure; cardiogenic shock [see Warnings and Precautions ( 5.2 )] . 4.3 Hypersensitivity Reactions ISTALOL is contraindicated in patients who have exhibited a hypersensitivity reaction to any component of this product in the past. 4.1 Asthma, COPD ISTALOL is contraindicated in patients with bronchial asthma; a history of bronchial asthma; severe chronic obstructive pulmonary disease [see Warnings and Precautions ( 5.1 , 5.3 )] . 4.2 Sinus Bradycardia, AV Block, Cardiac Failure, Cardiogenic Shock ISTALOL is contraindicated in patients with sinus bradycardia; second or third degree atrioventricular block; overt cardiac failure; cardiogenic shock [see Warnings and Precautions ( 5.2 )] . 4.3 Hypersensitivity Reactions ISTALOL is contraindicated in patients who have exhibited a hypersensitivity reaction to any component of this product in the past.
Overdose — what happens if you take too much
There have been reports of inadvertent overdosage with ISTALOL resulting in systemic effects similar to those seen with systemic beta-adrenergic blocking agents such as dizziness, headache, shortness of breath, bradycardia, bronchospasm, and cardiac arrest. An in vitro hemodialysis study, using 14 C timolol added to human plasma or whole blood, showed that timolol was readily dialyzed from these fluids; however, a study of patients with renal failure showed that timolol did not dialyze readily.
U.S. Poison Control: call or text 1-800-222-1222 (free, 24/7). In an emergency call 911. From the FDA label; not medical advice.
Interactions
Concomitant use with systemic beta-blockers may potentiate systemic beta-blockade. ( 7.1 ) Oral or intravenous calcium antagonists may cause atrioventricular conduction disturbances, left ventricular failure, and hypotension. ( 7.2 ) Catecholamine-depleting drugs may have additive effects and produce hypotension and/or marked bradycardia. ( 7.3 ) Digitalis and calcium antagonists may have additive effects in prolonging atrioventricular conduction time. ( 7.4 ) Potentiated systemic beta-blockade (e.g., decreased heart rate) has been reported during combined treatment with quinidine and timolol. ( 7.5 ) 7.1 Beta-Adrenergic Blocking Agents Patients who are receiving a beta-adrenergic blocking agent orally and ISTALOL should be observed for potential additive effects of beta-blockade, both systemic and on intraocular pressure. The concomitant use of two topical beta-adrenergic blocking agents is not recommended. 7.2 Calcium Antagonists Caution should be used in the co-administration of beta-adrenergic blocking agents, such as ISTALOL, and oral or intravenous calcium antagonists because of possible atrioventricular conduction disturbances, left ventricular failure, and hypotension. In patients with impaired cardiac function, co-administration should be avoided. 7.3 Catecholamine-Depleting Drugs Close observation of the patient is recommended when a beta-blocker is administered to patients receiving catecholamine-depleting drugs such as reserpine, because of possible additive effects and the production of hypotension and/or marked bradycardia, which may result in vertigo, syncope, or postural hypotension. 7.4 Digitalis and Calcium Antagonists The concomitant use of beta-adrenergic blocking agents with digitalis and calcium antagonists may have additive effects in prolonging atrioventricular conduction time. 7.5 CYP2D6 Inhibitors Potentiated systemic beta-blockade (e.g., decreased heart rate) has been reported during combined treatment with CYP2D6 inhibitors (e.g., quinidine) and timolol. 7.6 Clonidine Oral beta-adrenergic blocking agents may exacerbate the rebound hypertension which can follow the withdrawal of clonidine. There have been no reports of exacerbation of rebound hypertension with ophthalmic timolol maleate. 7.1 Beta-Adrenergic Blocking Agents Patients who are receiving a beta-adrenergic blocking agent orally and ISTALOL should be observed for potential additive effects of beta-blockade, both systemic and on intraocular pressure. The concomitant use of two topical beta-adrenergic blocking agents is not recommended. 7.2 Calcium Antagonists Caution should be used in the co-administration of beta-adrenergic blocking agents, such as ISTALOL, and oral or intravenous calcium antagonists because of possible atrioventricular conduction disturbances, left ventricular failure, and hypotension. In patients with impaired cardiac function, co-administration should be avoided. 7.3 Catecholamine-Depleting Drugs Close observation of the patient is recommended when a beta-blocker is administered to patients receiving catecholamine-depleting drugs such as reserpine, because of possible additive effects and the production of hypotension and/or marked bradycardia, which may result in vertigo, syncope, or postural hypotension. 7.4 Digitalis and Calcium Antagonists The concomitant use of beta-adrenergic blocking agents with digitalis and calcium antagonists may have additive effects in prolonging atrioventricular conduction time. 7.5 CYP2D6 Inhibitors Potentiated systemic beta-blockade (e.g., decreased heart rate) has been reported during combined treatment with CYP2D6 inhibitors (e.g., quinidine) and timolol. 7.6 Clonidine Oral beta-adrenergic blocking agents may exacerbate the rebound hypertension which can follow the withdrawal of clonidine. There have been no reports of exacerbation of rebound hypertension with ophthalmic timolol maleate.
Drug class
How this class works, per Beta Blockers — StatPearls, NCBI Bookshelf (NIH).
May treat (source: NIH RxClass)
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Dosage forms
Drops
The forms currently marketed in the U.S., per the FDA National Drug Code Directory.
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Frequently asked questions
- What does Istalol treat?
- Istalol (Timolol Maleate) may be used to treat angina pectoris, open-angle glaucoma, heart failure, hypertension, myocardial infarction, based on NIH RxClass drug-classification data (conditions a drug may treat — not a verbatim copy of the FDA-approved label). This is general reference, not medical advice.
- How does Istalol work?
- Istalol is a beta-adrenergic blocker. Beta-blockers block adrenaline (epinephrine) and noradrenaline from acting on beta-adrenergic receptors, mainly in the heart. This slows the heart rate, reduces how forcefully the heart contracts, and lowers blood pressure, easing the workload on the heart.
- How much does Istalol cost?
- Nobody can tell you what you will pay — your price is set by your insurer's formulary, your deductible and the pharmacy's markup, and none of those are published. What IS published is what the pharmacy paid to acquire it: about $1.06 per ml, per the CMS NADAC survey. Treat that as the floor, not the quote — ask the pharmacist for the cash price as well as your copay, because for cheap generics the cash price often wins.
- Is there a coupon or discount for Istalol?
- pharmaranks is an independent ratings site, not a pharmacy — we don't issue coupons or sell Istalol. To pay less, ask your prescriber or pharmacist whether a generic equivalent exists, check the manufacturer's copay/savings card and patient-assistance program, and compare a pharmacy discount card against your insurance copay. Prices vary by pharmacy, insurance, and location, so always confirm at the counter. This is general reference, not medical or financial advice.
- Who makes Istalol?
- Istalol is marketed by Bausch and Lomb. You can see Bausch and Lomb's full profile, rating, and other products on pharmaranks.
- Is Istalol a brand-name or generic drug?
- Istalol is a brand-name product with the active ingredient Timolol Maleate. Lower-cost generic equivalents containing Timolol Maleate are available — ask your pharmacist.
- Is Istalol available over the counter?
- No. Istalol is a prescription (Rx) medication in the US — you need a prescription from a licensed clinician (in person or via telehealth); it isn't sold over the counter. For some conditions there are OTC alternatives — ask your pharmacist.
- What forms does Istalol come in?
- Istalol is currently marketed as drops, per the FDA's National Drug Code Directory.
- What class of drug is Istalol?
- Istalol is classified as beta-adrenergic blocker, per the FDA's Established Pharmacologic Class.
- Is Istalol FDA-registered?
- Istalol is on record with the U.S. FDA under application number NDA021516. You can verify this on its official FDA label.
- Is Istalol safe?
- There's no single safe-or-not verdict, and we don't yet have a composite recall-safety score for Istalol. Review its FDA-label side effects and warnings below, and always consult a licensed professional.
- What are the side effects of Istalol?
- Istalol's side effects are taken directly from its FDA label. From the label: The most frequently reported adverse reactions have been burning and stinging upon instillation in 38% of patients treated with ISTALOL. Additional reactions reported with ISTALOL at a frequency of 4% to 10% include: blurred vision, cataract, conjunctival injection, headache, hypertension,… Both common and serious reactions are documented in full on this page. This is general reference from the FDA, not medical advice — always consult a professional.
Clinical content sourced from the FDA label via openFDA (U.S. FDA). View the FDA label on DailyMed → Provided for general reference only — not medical advice. Always consult a licensed professional and the current prescribing information.
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