Betaxolol

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

• 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. …

• Patients, especially those with evidence of coronary artery insufficiency, should be warned against interruption or discontinuation of betaxolol 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. …

• 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 )

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. …

Cardiac Failure Sympathetic stimulation may be a vital component supporting circulatory function in congestive heart failure, and beta-adrenergic receptor blockade carries the potential hazard of further depressing myocardial contractility and precipitating more severe heart failure. In hypertensive patients who have congestive heart failure controlled by digitalis and diuretics, beta-blockers should be administered cautiously. Both digitalis and beta-adrenergic receptor blocking agents slow AV conduction. 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. …

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. …

Pregnancy Pregnancy Category C In a study in which pregnant rats received betaxolol at doses of 4, 40, or 400 mg/kg/day, the highest dose (600 × MRHD) was associated with increased postimplantation loss, reduced litter size and weight, and an increased incidence of skeletal and visceral abnormalities, which may have been a consequence of drug-related maternal toxicity. …

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. …

Take it when you remember, unless it is nearly time for the next dose. Then skip the missed one. Never take two doses at once to make up for it. Check your leaflet, as some medicines are different.