Drug Interactions The following drugs have been coadministered with betaxolol and have not altered its pharmacokinetics: cimetidine, nifedipine, chlorthalidone, and hydrochlorothiazide. Concomitant administration of betaxolol with the oral anticoagulant warfarin has been shown not to potentiate the anticoagulant effect of warfarin. Catecholamine-depleting drugs (eg, 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, eg, nifedipine, while left ventricular failure and AV conduction disturbances, including complete heart block, were more likely to occur with either verapamil or diltiazem. Both digitalis glycosides and beta-blockers slow atrioventricular conduction and decrease heart rate. Concomitant use can increase the risk of bradycardia. Amiodarone is an antiarrhythmic agent with negative chronotropic properties that may be additive to those seen with beta blockers. Disopyramide is a Type I antiarrhythmic drug with potent negative inotropic and chronotropic effects. Disopyramide has been associated with severe bradycardia, asystole and heart failure when administered with beta blockers. Particular care should be taken when using anesthetic agents which depress the myocardium, such as ether, cyclopropane, and trichloroethylene (see Warnings, Major surgery ).
BETOPTIC S is contraindicated in patients with: sinus bradycardia greater than a first degree atrioventricular (AV) block cardiogenic shock patients with overt cardiac failure hypersensitivity to any component of this product Hypersensitivity to any component of this product. ( 4 ) Sinus bradycardia, second or third degree atrioventricular (AV) block, overt cardiac failure, and cardiogenic shock. ( 4 )
AND PRECAUTIONS Systemic Absorption : Same adverse reactions found with systemic administration of beta-adrenergic receptor inhibitors may occur with topical ophthalmic administration. ( 5.1 )
Cardiac
Failure : Discontinue treatment at the first signs of cardiac failure. ( 5.2 )
Diabetes
Mellitus : Beta-adrenergic receptor inhibitors may mask the signs and symptoms of acute hypoglycemia. Administer with caution in diabetic patients subject to hypoglycemia. ( 5.3 ) Thyrotoxicosis : Beta-adrenergic receptor inhibitors may mask certain clinical signs (e.g., tachycardia) or hyperthyroidism. ( 5.4 )
5.1 Systemic Absorption As with many topically applied ophthalmic drugs, this drug is absorbed systemically. The same adverse reactions found with systemic administration of beta-adrenergic receptor inhibitors may occur with topical administration. For example, severe respiratory reactions and cardiac reactions, including death due to bronchospasm in patients with asthma, and death due to cardiac failure, have been reported with topical application of beta-adrenergic receptor inhibitors.
5.2 Cardiac Failure BETOPTIC S has been shown to have a minor effect on heart rate and blood pressure in clinical studies. Caution should be used in treating patients with a history of cardiac failure or heart block. Treatment with BETOPTIC S should be discontinued at the first signs of cardiac failure.
5.3 Diabetes Mellitus Beta-adrenergic receptor inhibitors should be administered with caution in patients subject to hypoglycemia or to diabetic patients (especially those with labile diabetes) who are receiving insulin or oral hypoglycemic agents. Beta-adrenergic receptor inhibitors may mask the signs and symptoms of acute hypoglycemia.
5.4 Thyrotoxicosis Beta-adrenergic receptor inhibitors 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 receptor inhibitors, which might precipitate a thyroid storm.
5.5 Muscle Weakness Beta-adrenergic receptor inhibitors have been reported to potentiate muscle weakness consistent with certain myasthenic symptoms (e.g., diplopia, ptosis, and generalized weakness).
5.6 Surgical Anesthesia The necessity or desirability of withdrawal of beta-adrenergic receptor inhibitors prior to major surgery is controversial. Beta-adrenergic receptor inhibitors impair 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 inhibitors have experienced protracted, severe hypotension during anesthesia. Difficulty in restarting and maintaining the heartbeat has also been reported. In patients undergoing elective surgery, consider gradual withdrawal of beta-adrenergic receptor inhibitors. If necessary during surgery, the effects of beta-adrenergic receptor inhibitors may be reversed by sufficient doses of adrenergic agonists.
5.7 Bronchospasm and Obstructive Pulmonary Disease Caution should be exercised in the treatment of glaucoma patients with excessive restriction of pulmonary function. There have been reports of asthmatic attacks and pulmonary distress during betaxolol treatment. Although rechallenges of some such patients with ophthalmic betaxolol has not adversely affected pulmonary function test results, the possibility of adverse pulmonary effects in patients sensitive to beta-adrenergic receptor inhibitors cannot be ruled out.
5.8 Atopy/Anaphylaxis While taking beta-adrenergic receptor inhibitors, patients with a history of atopy or a history of severe anaphylactic reaction 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.
5.9 Angle-Closure Glaucoma In patients with angle-closure glaucoma, the immediate treatment objective is to reopen the angle. This may require constricting the pupil. Betaxolol has little or no effect on the pupil and should not be used alone in the treatment of angle-closure glaucoma.
5.10 Vascular Insufficiency Because of potential effects of beta-adrenergic receptor inhibitors on blood pressure and pulse, these inhibitors should be used with caution in patients with vascular insufficiency. If signs or symptoms suggesting reduced cerebral blood flow or Raynaud’s phenomenon develop following initiation of therapy with BETOPTIC S, alternative therapy should be considered.
5.11 Bacterial Keratitis Bacterial keratitis may occur with use of multiple dose containers of topical ophthalmic products when these containers are inadvertently contaminated by patients who, in most cases, had a concurrent corneal disease or a disruption of the ocular epithelial surface. Instruct patients on appropriate instillation techniques <span class="opacity-50 text-xs">[see Patient Counseling Information (17)]</span> .
5.12 Choroidal Detachment Choroidal detachment after filtration procedures has been reported with the administration of aqueous suppressant therapy.
5.13 Contact Lens Wear The preservative in BETOPTIC S, benzalkonium chloride, may be absorbed by soft contact lenses. Contact lenses should be removed during instillation of BETOPTIC S but may be reinserted 15 minutes after instillation <span class="opacity-50 text-xs">[see Patient Counseling Information (17)]</span> .