Beta-adrenoceptor blocking drugs

Beta-adrenergic blocking drugs: A class of drugs, also called beta-blockers, that block beta-adrenergic substances such as adrenaline (epinephrine), a key agent in the “sympathetic” portion of the autonomic (involuntary) nervous system.

By blocking the action of the sympathetic nervous system on the heart, these agents relieve stress on the heart. They slow the heartbeat, lessen the force with which the heart muscle contracts and reduce blood vessel contraction in the heart, brain, and throughout the body. Beta-blockers can serve to treat abnormal heart rhythms (cardiac arrhythmias). They are used specifically to prevent abnormally fast heart rates (tachycardias) or irregular heart rhythms such as premature ventricular beats. Since beta-blockers reduce the demand of the heart muscle for oxygen and the chest pain of angina pectoris occurs when the oxygen demand of the heart exceeds the supply, beta-blockers can be useful in treating angina. They have also become an important drug in improving survival after a person has had a heart attack.

PROPRANOLOL:

Indications: Propranolol is prescribed for patients with high blood pressure (hypertension). It is also used to treat chest pain (angina pectoris) related to coronary artery disease. Propranolol is also useful in slowing and regulating certain types of abnormally rapid heart rates (tachycardias). Other uses for propranolol include the prevention of migraine headaches and the treatment of certain types of tremors (familial or hereditary essential tremors). Propranolol is commonly used in persons with thyrotoxicosis (high blood levels of thyroid hormone) to slow down rapid heart rate and tremor.

Contraindications: asthma, history of obstructive airways disease, uncontrolled heart failure, sinus, bradycardia, phaeochromocytoma, Cardiac failure, cardiogenic shock, and heartblock.

Dose and Administration: orally, 80mg twice daily increased at weekly Intervals as required, maintenance 160-320mg daily.

IV injection – 1.3mg administered at a rate not to exceed 1mg/minute, repeated after two minutes and again after four hours if necessary (for Antiarrhythmic).

ATENOLOL:

Indications: indicated in the management of hypertension. It may be used alone or concomitantly with other antihypertensive agents, particularly with a thiazide-type diuretic. Atenolol is indicated for the long-term management of patients with angina pectoris also indicated in the management of hemodynamically stable patients with definite or suspected acute myocardial infarction to reduce cardiovascular mortality.

Contraindications: contraindicated in sinus bradycardia, heart block greater than first degree, cardiogenic shock, and overt cardiac failure

Dose and Administration: – Atenolol should be taken before meals or at bedtime. The dose for treating high blood pressure or angina is 50-100 mg once daily.

BISOPROLOL:

Indications: Bisoprolol is used alone or with other drugs for treating patients with high blood pressure. It also used for treating angina and congestive heart failure.

Contraindications: contraindicated in patients with cardiogenic shock, overt cardiac failure, second or third degree AV block, and marked sinus bradycardia. Dose and Administration: The usual starting dose is 5 mg once daily. In some patients, 2.5 mg may be an appropriate starting dose. If the antihypertensive effect of 5 mg is inadequate, the dose may be increased to 10 mg and then, if necessary, to 20 mg once daily. In patients with hepatic impairment (hepatitis or cirrhosis) or renal dysfunction (creatinine clearance less than 40 mL/min), the initial daily dose should be 2.5 mg and caution should be used in dose-titration.

CARVEDILOL:

Indications: indicated for the management of essential hypertension. It can be used alone or in combination with other antihypertensive agents, especially thiazide-type diuretics. indicated for the treatment of mild-to-severe chronic heart failure of ischemic or cardiomyopathic origin, usually in addition to diuretics, ACE inhibitors, and digitalis, to increase survival and, also, to reduce the risk of hospitalization. indicated to reduce cardiovascular mortality in clinically stable patients who have survived the acute phase of a myocardial infarction and have a left ventricular ejection fraction of ≤ 40% (with or without symptomatic heart failure).

Contraindications: contraindicated in the following conditions:

Bronchial asthma or related bronchospastic conditions. Second- or third-degree AV block. Sick sinus syndrome. Severe bradycardia (unless a permanent pacemaker is in place). Patients with cardiogenic shock or who have decompensated heart failure requiring the use of intravenous inotropic therapy. Patients with severe hepatic impairment.

Dose and Administration: The recommended starting dose of Carvedilol is 6.25 mg twice daily. If this dose is tolerated, using standing systolic pressure measured about 1 hour after dosing as a guide, the dose should be maintained for 7 to 14 days, and then increased to 12.5 mg twice daily if needed, based on trough blood pressure, again using standing systolic pressure one hour after dosing as a guide for tolerance. This dose should also be maintained for 7 to 14 days and can then be adjusted upward to 25 mg twice daily if tolerated and needed. The full antihypertensive effect of Carvedilol is seen within 7 to 14 days. Total daily dose should not exceed 50 mg.

ESMOLOL:

Indications: indicated for the treatment of tachycardia and hypertension that occur during induction and tracheal intubation, during surgery, on emergence from anesthesia, and in the postoperative period, when in the physician’s judgment such specific intervention is considered indicated. Also indicated for the rapid control of ventricular rate in patients with atrial fibrillation or atrial flutter in perioperative, postoperative, or other emergent circumstances where short term control of ventricular rate with a short- acting agent is desirable.

Contraindications: contraindicated in patients with sinus bradycardia, heart block greater than first degree, cardiogenic shock or overt heart failure.

Dose and Administration: An initial loading dose of 0.5 milligrams/kg (500 micrograms/kg) infused over a minute duration followed by a maintenance infusion of 0.05 milligrams/kg/min (50 micrograms/kg/min) for the next 4 minutes is recommended. the maintenance infusion may be continued at 0.05 mg/kg/min or increased step-wise (e.g. 0.1 mg/kg/min, 0.15 mg/kg/min to a maximum of 0.2 mg/kg/min) with each step being maintained for 4 or more minutes.

LABETALOL:

Indications: hypertension (including hypertension in pregnancy, hypertension with angina, and hypertension following acute myocardial infarction); hypertensive crisis); controlled hypotension in anaesthesia.

Contraindications: contraindicated in bronchial asthma, overt cardiac failure, greater-than-first-degree heart block, cardiogenic shock, severe bradycardia, other conditions associated with severe and prolonged hypotension.

Dose and Administration: The initial intravenous dose of labetalol is 20 mg injected over 2 minutes. Additional injections of 40 or 80 mg may be administered every 10 minutes as needed up to a total dose of 300 mg. Maximum effect is usually seen within 5 minutes after intravenous administration. Labetalol also may be administered by intravenous infusion.

METOPROLOL:

Indications: indicated for the treatment of hypertension alone or in combination with other antihypertensive agents. long-term treatment of angina pectoris. indicated in the treatment of hemodynamically stable patients with definite or suspected acute myocardial infarction to reduce cardiovascular mortality.

Contraindications: contraindicated in sinus bradycardia, heart block greater than first degree, cardiogenic shock, and overt cardiac failure.

Dose and Administration: The usual initial dosage is 100 mg daily in single or divided doses. The effective dosage range is 100- 450 mg per day.

Atenolol-Chlorthalidone:

Indications: indicated in the treatment of hypertension. This fixed dose combination drug is not indicated for initial therapy of hypertension. If the fixed dose combination represents the dose appropriate to the individual patient’sneeds, it may be more convenient than the separate components. Contraindications: contraindicated in patients with: sinus bradycardia; heart block greater than first degree; cardiogenic shock; overt cardiac failure; anuria; hypersensitivity to this product or to sulfonamide-derived drugs.

Dose and Administration: one tablet daily

Bisoprolol and Hydrochlorothiazide:

Indications: indicated in the management of hypertension.

Contraindications: contraindicated in patients in cardiogenic shock, overt cardiac failure, second or third degree AV block, marked sinus bradycardia, anuria, and hypersensitivity to either component of this product or to other sulfonamide-derived drugs.

Dose and Administration:  Bisoprolol is an effective treatment of hypertension in once-daily doses of 2.5 to 40 mg, while hydrochlorothiazide is effective in doses of 12.5 to 50 mg. In clinical trials of bisoprolol/hydrochlorothiazide combination therapy using bisoprolol doses of 2.5 to 20 mg and hydrochlorothiazide doses of 6.25 to 25 mg, the antihypertensive effects increased with increasing doses of either component.