| name: | Beta Blockers |
| also known as: | Atenolol (Tenormin); Esmolol (Brevibloc); Acebutolol (Sectral); Metoprolol (Toprol, Lopressor); Propranolol (Inderal, Propanolol); Timolol (Timoptic); Nadolol (Corgard); Pindolol (Visken); Labetalol (Normadyne, Trandate); Butoxamine; Tenoretic; Inderide; Sotalol (Betapace); Class II Antiarrhythmia Drugs; Adrenergic Antagonist; Sympatholytic; Sympathetic Blocker; Sympathetic Antagonist |
| also see: | Alpha Blockers; Guanethidine; Diuretics; Vasodilators; Ace Inhibitors; Ace II Inhibitors; High Blood Pressure Medicine; High Blood Pressure; Angina; Arrhythmia; Antiarrhythmia Drugs; Beta Blocker Overdose |
| description: | The nervous system is comprised of the central nervous system, brain and spinal cord, and the peripheral nervous system, motor and autonomic. The motor system, also called somatic nervous system, moves skeletal muscle. The autonomic system is further divided into the sympathetic nervous system and parasympathetic nervous system. The sympathetic nervous system is the "flight or fight" system. The parasympathetic nervous system is the "rest and digest" system. The sympathetic nervous system is triggered by chemicals variously called: catecholamines, adrenergic agonists, or sympathomimetics. Within this system are four types of receptors, alpha 1, alpha 2, beta 1, and beta 2 and each receptor type effects a certain part of the body. Some catecholamines trigger all four receptors while others are more selective in their action. Knowing this, certain sympathomimetics can be used as drugs to treat a particular problem. Alpha 1 receptors are involved with vasoconstriction, decrease intestinal motility, bladder sphincter contraction, ejaculation, uterine contraction, and pupil dilation. Alpha 2 receptors primarily work to inhibit further alpha 1 action as a negative feedback loop. Beta 1 receptors work primarily to stimulate the heart to contract more forcibly. Beta 2 receptors work on the heart to contract, too, and also work to relax lung smooth muscle leading to lung airway dilation (bronchodilation), uterus relaxation and bladder relaxation. Beta blockers block either beta 1 or beta 2 receptors, or both. Classic beta 1 blockers include atenolol and metoprolol in which they selectively decrease the contraction of the heart, thereby decreasing cardiac output and lowering blood pressure. They are sometimes called cardio-selective beta blockers. They are used in the treatment of high blood pressure. Additionally, metoprolol is also used to treat angina and heart attacks while esmolol is often used to treat the thyroid storm of hyperthyroidism. Selective beta 1 blockers do not cause bronchoconstriction so they are more likely used as a blood pressure medicine in people who suffer from asthma over their cousin, propranolol. Propranolol (Inderal) is a beta 1 and beta 2 blocker, the original beta blocker, sometimes called a non-selective beta blocker. It is used in the treatment of high blood pressure, angina, rapid heartbeat, heart arrhythmia, panic disorder, migraine headache, and thyroid storm of hyperthyroidism. Other similar drugs are timolol and nadolol which are used to treat glaucoma. Non-selective beta blockers are usually not used in asthma patients and in diabetics on insulin. Acebutolol and pindolol are used to treat high blood pressure in patients prone to slow heart rate. The three main beta blockers used in the treatment of heart arrhythmia are propranolol, sotalol, and esmolol. Sotalol is used for ventricular arrhythmia and esmolol for arrhythmia that occur during surgery. Carvedilol is a beta blocker approved for the treatment of congestive heart failure. As antianginal drugs, beta blockers reduce heart rate, reduce blood pressure, and reduce the work of the heart. |
| signs & symptoms: | Side effects of all beta blockers but especially the non-selective beta blockers such as propranolol, include slow heart rate, fatigue, depression, sexual dysfunction, bronchoconstriction, exacerbation of asthma, and blunted low blood sugar warning signs in diabetics. Also see beta blocker overdose High blood pressure can be divided into three stages: Stage 1 - Mild: Systolic BP 140-159 and/or Diastolic BP 90-99 Stage 2 - Moderate: Systolic BP 160-180 and/or Diastolic BP 100-110 Stage 3 - Severe: Systolic BP > 180 and/or Diastolic BP > 110 |
| treatment: | Usually given orally. Also see Rx labetalol (normadyne, trandate) Also see Rx propranolol (inderal) Also see Rx acebutolol (sectral) Also see Rx atenolol (tenormin) Also see Rx metoprolol (lopressor, toprol) Also see Rx nadolol (corgard) Also see Rx pindolol (visken) Also see Rx timolol (blocadren) Also see Rx sotalol (betapace) Also see Rx atenolol/chlorthalidone (tenoretic) Also see Rx hydrochlorothiazide/propranolol (inderide) Also see Rx carteolol (cartrol) Also see Rx carvedilol (coreg) Also see Rx bendroflumethiazide/nadolol (corzide) Also see Rx betaxolol (kerlone) Also see Rx penbutolol (levatol) Also see Rx hydrochlorothiazide/metoprolol (lopressor HCT) Also see Rx hydrochlorothiazide/timolol (timolide) Also see Rx bisoprolol (zebeta) Also see Rx bisoprolol/hydrochlorothiazide (ziac) Also see Rx esmolol (brevibloc) Eye: Also see Rx timolol ophthalmic (timoptic ophthalmic) |
| prevention: | Patients who have asthma, diabetes, chronic obstructive pulmonary disease, severe congestive heart failure and peripheral vascular disease should probably not take beta blockers. |
skynetMD suggests the following:
| if: | If you have questions, problems, or concerns regarding any medication |
| go to: | Go to the phone and ask your pharmacist or your doctor, or go to the doctor. |
Last updated 9/12/2007