Betoptic - General Information
A cardioselective beta-1-adrenergic antagonist with no partial agonist activity.
Pharmacology of Betoptic
Betoptic is a competitive, beta(1)-selective (cardioselective) adrenergic antagonist. Betoptic is used to treat hypertension, arrhythmias, coronary heart disease, glaucoma, and is also used to reduce non-fatal cardiac events in patients with heart failure. Activation of beta(1)-receptors (located mainly in the heart) by epinephrine increases the heart rate and the blood pressure, and the heart consumes more oxygen. Drugs such as betaxolol that block these receptors therefore have the reverse effect: they lower the heart rate and blood pressure and hence are used in conditions when the heart itself is deprived of oxygen. They are routinely prescribed in patients with ischemic heart disease. In addition, beta(1)-selective blockers prevent the release of renin, which is a hormone produced by the kidneys which leads to constriction of blood vessels. Betoptic is lipophilic and exhibits no intrinsic sympathomimetic activity (ISA) or membrane stabilizing activity.
Betoptic for patients
Patients, especially those with evidence of coronary artery insufficiency, should be warned against interruption or discontinuation of Kerlone therapy without the physician's advice.
Although cardiac failure rarely occurs in appropriately selected patients, patients being treated with beta-adrenergic blocking agents should be advised to consult a physician at the first sign or symptom of failure.
Patients should know how they react to this medicine before they operate automobiles and machinery or engage in other tasks requiring alertness. Patients should contact their physician if any difficulty in breathing occurs, and before surgery of any type. Patients should inform their physicians or dentists that they are taking Kerlone. Patients with diabetes should be warned that beta-blockers may mask tachycardia occurring with hypoglycemia.
How to Use This Medicine:
- Your doctor will tell you how much of this medicine to take and how often. Do not take more medicine or take it more often than your doctor tells you to.
- You may take this medicine with or without food.
If a dose is missed:
- If you miss a dose or forget to use your medicine, use it as soon as you can. If your next regular dose is less than 8 hours away, wait until then to use the medicine and skip the missed dose.
- Do not use extra medicine to make up for a missed dose.
How to Store and Dispose of This Medicine:
- Store the medicine at room temperature, away from heat, moisture, and direct light.
- Keep all medicine out of the reach of children and never share your medicine with anyone.
The following drugs have been coadministered with Kerlone and have not altered its pharmacokinetics: cimetidine, nifedipine, chlorthalidone, and hydrochlorothiazide. Concomitant administration of Kerlone with the oral anticoagulant warfarin has been shown not to potentiate the anticoagulant effect of warfarin.
Catecholamine-depleting drugs (e.g., reserpine) may have an additive effect when given with beta-blocking agents. Patients treated with a beta-adrenergic receptor blocking agent plus a catecholamine depletor should therefore be closely observed for evidence of hypotension or marked bradycardia, which may produce vertigo, syncope, or postural hypotension.
Should it be decided to discontinue therapy in patients receiving beta-blockers and clonidine concurrently, the beta-blocker should be discontinued slowly over several days before the gradual withdrawal of clonidine.
Literature reports suggest that oral calcium antagonists may be used in combination with beta-adrenergic blocking agents when heart function is normal, but should be avoided in patients with impaired cardiac function. Hypotension, AV conduction disturbances, and left ventricular failure have been reported in some patients receiving beta-adrenergic blocking agents when an oral calcium antagonist was added to the treatment regimen. Hypotension was more likely to occur if the calcium antagonist were a dihydropyridine derivative, e.g., nifedipine, while left ventricular failure and AV conduction disturbances, including complete heart block, were more likely to occur with either verapamil or diltiazem.
Risk of Anaphylactic Reaction: Although it is known that patients on beta-blockers may be refractory to epinephrine in the treatment of anaphylactic shock, beta-blockers can, in addition, interfere with the modulation of allergic reaction and lead to an increased severity and/or frequency of attacks. Severe allergic reactions including anaphylaxis have been reported in patients exposed to a variety of allergens either by repeated challenge, or accidental contact, and with diagnostic or therapeutic agents while receiving beta-blockers. Such patients may be unresponsive to the usual doses of epinephrine used to treat allergic reaction.
Contraindications include hypersensitivity to betaxolol or any component of the formulation; sinus bradycardia; heart block greater than first-degree (except in patients with a functioning artificial pacemaker); cardiogenic shock; uncompensated cardiac failure; pulmonary edema; pregnancy (2nd or 3rd trimester).
Additional information about Betoptic
Betoptic Indication: For the management of hypertension.
Mechanism Of Action: Betoptic selectively blocks catecholamine stimulation of beta(1)-adrenergic receptors in the heart and vascular smooth muscle. This results in a reduction of heart rate, cardiac output, systolic and diastolic blood pressure, and possibly reflex orthostatic hypotension. Betoptic can also competitively block beta(2)-adrenergic responses in the bronchial and vascular smooth muscles, causing bronchospasm.
Drug Interactions: Not Available
Food Interactions: Not Available
Generic Name: Betaxolol
Synonyms: Betazolol; Betaxolol HCL; Betaxololum [INN-Latin]
Drug Category: Sympatholytics; Antihypertensive Agents; Adrenergic beta-Antagonists; EENT Drugs
Drug Type: Small Molecule; Approved
Absorption: Absorption of an oral dose is complete. There is a small and consistent first-pass effect resulting in an absolute bioavailability of 89% ± 5% that is unaffected by the concomitant ingestion of food or alcohol.
Toxicity (Overdose): Oral LD50s are 350 to 400 mg betaxolol/kg in mice and 860 to 980 mg/kg in rats. Predicted symptoms of overdose include bradycardia, congestive heart failure, hypotension, bronchospasm, and hypoglycemia.
Protein Binding: 50%
Biotransformation: Primarily hepatic. Approximately 15% of the dose administered is excreted as unchanged drug, the remainder being metabolites whose contribution to the clinical effect is negligible.
Half Life: 14-22 hours
Dosage Forms of Betoptic: Suspension Ophthalmic
Chemical IUPAC Name: 1-[4-[2-(cyclopropylmethoxy)ethyl]phenoxy]-3-(propan-2-ylamino)propan-2-ol
Chemical Formula: C18H29NO3
Betaxolol on Wikipedia: https://en.wikipedia.org/wiki/Betaxolol
Organisms Affected: Humans and other mammals