Betaxolol

INDICATIONS AND USAGE Betaxolol is indicated in the management of hypertension. It may be used alone or concomitantly with other antihypertensive agents, particularly thiazide-type diuretics.

DOSAGE AND ADMINISTRATION The initial dose of betaxolol in hypertension is ordinarily 10 mg once daily either alone or added to diuretic therapy. The full antihypertensive effect is usually seen within 7 to 14 days. If the desired response is not achieved the dose can be doubled after 7 to 14 days. Increasing the dose beyond 20 mg has not been shown to produce a statistically significant additional antihypertensive effect; but the 40-mg dose has been studied and is well tolerated. An increased effect (reduction) on heart rate should be anticipated with increasing dosage. If monotherapy with betaxolol does not produce the desired response, the addition of a diuretic agent or other antihypertensive should be considered (see, Drug Interactions ). Dosage Adjustments for Specific Patients Patients with renal failure In patients with renal impairment, clearance of betaxolol declines with decreasing renal function. In patients with severe renal impairment and those undergoing dialysis the initial dose of betaxolol is 5 mg once daily. If the desired response is not achieved, dosage may be increased by 5 mg/day increments every 2 weeks to a maximum dose of 20 mg/day. Patients with hepatic disease Patients with hepatic disease do not have significantly altered clearance. Dosage adjustments are not routinely needed. Elderly patients Consideration should be given to reduction in the starting dose to 5 mg in elderly patients. These patients are especially prone to beta-blocker-induced bradycardia, which appears to be dose related and sometimes responds to reductions in dose. Cessation of therapy If withdrawal of betaxolol therapy is planned, it should be achieved gradually over a period of about 2 weeks. Patients should be carefully observed and advised to limit physical activity to a minimum.

CONTRAINDICATIONS Betaxolol is contraindicated in patients with known hypersensitivity to the drug. Betaxolol is contraindicated in patients with sinus bradycardia, heart block greater than first degree, cardiogenic shock, and overt cardiac failure. (see Warnings ).

ADVERSE REACTIONS Most adverse reactions have been mild and transient and are typical of beta-adrenergic blocking agents, eg, bradycardia, fatigue, dyspnea, and lethargy. Withdrawal of therapy in U.S. and European controlled clinical trials has been necessary in about 3.5% of patients, principally because of bradycardia, fatigue, dizziness, headache, and impotence. Frequency estimates of adverse events were derived from controlled studies in which adverse reactions were volunteered and elicited in U.S. studies and volunteered and/or elicited in European studies. In the U.S., the placebo-controlled hypertension studies lasted for 4 weeks, while the active-controlled hypertension studies had a 22- to 24-week double-blind phase. The following doses were studied: betaxolol—5, 10, 20, and 40 mg once daily; atenolol—25, 50, and 100 mg once daily; and propranolol—40, 80, and 160 mg b.i.d. Betaxolol, like other beta-blockers, has been associated with the development of antinuclear antibodies (ANA) (e.g., lupus erythematosus). In controlled clinical studies, conversion of ANA from negative to positive occurred in 5.3% of the patients treated with betaxolol, 6.3% of the patients treated with atenolol, 4.9% of the patients treated with propranolol, and 3.2% of the patients treated with placebo. Betaxolol adverse events reported with a 2% or greater frequency, and selected events with lower frequency, in U.S. controlled studies are: Dose Range Body System/Adverse Reaction Betaxolol (N=509) 5-40 mg q.d.* (%) Propranolol (N=73) 40-160 mg b.i.d. (%) Atenolol (N=75) 25-100 mg q.d. (%) Placebo (N=109) (%) Cardiovascular Bradycardia (heart rate <50 BPM) Symptomatic bradycardia Edema 8.1 0.8 1.8 4.1 1.4 0 12.0 0 0 0 0 1.8 Central Nervous System Headache Dizziness Fatigue Lethargy 6.5 4.5 2.9 2.8 4.1 11.0 9.6 4.1 5.3 2.7 4.0 2.7 15.6 5.5 0 0.9 Psychiatric Insomnia Nervousness Bizarre dreams Depression 1.2 0.8 1.0 0.8 8.2 1.4 2.7 2.7 2.7 2.7 1.3 4.0 0 0 0 0 Autonomic Impotence 1.2† 0 0 0 Respiratory Dyspnea Pharyngitis Rhinitis Upper respiratory infection 2.4 2.0 1.4 2.6 2.7 0 0 0 1.3 4.0 4.0 0 0.9 0.9 0.9 5.5 Gastrointestinal Dyspepsia Nausea Diarrhea 4.7 1.6 2.0 6.8 1.4 6.8 2.7 4.0 8.0 0.9 0 0.9 Musculoskeletal Chest pain Arthralgia 2.4 3.1 1.4 0 2.7 4.0 0.9 1.8 Skin Rash 1.2 0 0 0 *Five patients received 80 mg q.d. †N=336 males; impotence is a known possible adverse effect of this pharmacological class. Of the above adverse reactions associated with the use of betaxolol, only bradycardia was clearly dose related, but there was a suggestion of dose relatedness for fatigue, lethargy, and dyspepsia. In Europe, the placebo-controlled study lasted for 4 weeks, while the comparative studies had a 4-52-week double-blind phase. The following doses were studied: betaxolol 20 and 40 mg once daily and atenolol 100 mg once daily. From European controlled hypertension clinical trials, the following adverse events reported by 2% or more patients and selected events with lower frequency are presented: Dose Range Body System/Adverse Reaction Betaxolol (N=155) 20-40 mg q.d. (%) Atenolol (N=81) 100 mg q.d. (%) Placebo (N=60) (%) Cardiovascular Bradycardia (heartrate <50 BPM) Symptomatic bradycardia Palpitation Edema Cold extremities 5.8 1.9 1.9 1.3 1.9 5.0 2.5 3.7 1.2 0 0 0 1.7 0 0 Central Nervous System Headache Dizziness Fatigue Asthenia Insomnia Paresthesia 14.8 14.8 9.7 7.1 5.0 1.9 9.9 17.3 18.5 0 3.7 2.5 23.3 15.0 0 16.7 3.3 0 Gastrointestinal Nausea Dyspepsia Diarrhea 5.8 3.9 1.9 1.2 7.4 3.7 0 3.3 0 Musculoskeletal Chest pain Joint pain Myalgia 7.1 5.2 3.2 6.2 4.9 3.7 5.0 1.7 3.3 The only adverse event whose frequency clearly rose with increasing dose was bradycardia. Elderly patients were especially susceptible to bradycardia, which in some cases responded to dose-reduction (see Precautions ). The following selected (potentially important) adverse events have been reported at an incidence of less than 2% in U.S. controlled and open, long-term clinical stu …

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 ).

DESCRIPTION Betaxolol is a β 1 -selective (cardioselective) adrenergic receptor blocking agent available as 10-mg and 20-mg tablets for oral administration. Betaxolol is chemically described as 2-propanol,1-[4-[2-(cyclopropylmethoxy)ethyl]phenoxy]-3-[(1-methylethyl)amino]-,hydrochloride,(±). It has the following chemical structure: Betaxolol hydrochloride is a water-soluble white crystalline powder with a molecular formula of C 18 H 29 NO 3 •HCl and a molecular weight of 343.9. It is freely soluble in water, ethanol, chloroform, and methanol, and has a pKa of 9.4. The inactive ingredients are anhydrous lactose, carnauba wax, hypromellose, microcrystalline cellulose, polyethylene glycol, polysorbate 80, pregeletanized starch (corn), sodium starch glycolate, stearic acid and titanium dioxide. Molecular Weight 343.9

OVERDOSAGE No specific information on emergency treatment of overdosage with betaxolol is available. The most common effects expected are bradycardia, congestive heart failure, hypotension, bronchospasm, and hypoglycemia. In one acute overdosage of betaxolol, a 16-year-old female recovered fully after ingesting 460 mg. Oral LD 50 s are 350 to 400 mg betaxolol/kg in mice and 860 to 980 mg/kg in rats. In the case of overdosage, treatment with betaxolol should be stopped and the patient carefully observed. Hemodialysis or peritoneal dialysis does not remove substantial amounts of the drug. In addition to gastric lavage, the following therapeutic measures are suggested if warranted: Hypotension Use sympathomimetic pressor drug therapy, such as dopamine, dobutamine, or norepinephrine. In refractory cases of overdosage of other beta-blockers, the use of glucagon hydrochloride has been reported to be useful. Bradycardia Atropine should be administered. If there is no response to vagal blockade, isoproterenol should be administered cautiously. (see Warnings: Major Surgery ). In refractory cases the use of a transvenous cardiac pacemaker may be considered. Acute cardiac failure Conventional therapy including digitalis, diuretics, and oxygen should be instituted immediately. Bronchospasm Use a β 2 -agonist. Additional therapy with aminophylline may be considered. Heart block (2nd- or 3rd-degree) Use isoproterenol or a transvenous cardiac pacemaker.

HOW SUPPLIED Betaxolol Tablets USP, 10 mg* contains 10 mg betaxolol hydrochloride (equivalent to 8.94 mg betaxolol) are white, round biconvex, film-coated tablets, debossed “ Є ” above and “38” below bisect on one side and plain on the other side. They are supplied as: NDC 24658-700-01 Bottles of 100 Tablets Betaxolol Tablets USP, 20 mg* contains 20 mg betaxolol hydrochloride (equivalent to 17.88 mg betaxolol) are white, round biconvex, film-coated tablets, debossed “ Є ” above “39” on one side and plain on the other side. They are supplied as: NDC 24658-701-01 Bottles of 100 Tablets Store at 20°–25°C (68°–77°F) [See USP Controlled Room Temperature]. Distributed by: PuraCap Laboratories, LLC DBA Blu Pharmaceuticals Franklin, KY 42134 USA 1-877-264-0258 Manufactured in USA Issued August 2016 MF038ISS08/16 OE2568