Beta-Adrenergic Blocking Agents
Beta-Adrenergic Blocking Agents, or Beta Blockers, are a class of drugs used to reduce systolic heart pressure, heart rate and the heart’s demand for oxygen.
Originally developed in the 1960s, they are used to treat abnormal heart rhythms, angina (heart pain), high blood pressure, migraines and glaucoma. In some situations, they may be prescribed for performance anxiety or stage fright. They work by blocking stress hormones such as adrenaline from attaching to the cells of the heart, smooth muscles, arteries, kidneys, eyes, liver, uterus and other parts of the sympathetic nervous system (involved in the “flight or fight” response).
Because they also work on the bronchial system, they must be used with care by anyone with a respiratory disorder such as asthma. Certain beta blockers may be more likely to affect the airways than others. Beta blockers may cause nausea, diarrhea, upset stomach, dizziness, fatigue, hair loss, rash, muscle cramps, abnormal vision, insomnia, nightmares, sexual dysfunction, hallucinations, low blood pressure, slow heart rate, bronchial spasms, and may change the way glucose or lipids are metabolized.
Some newer beta blockers target certain body systems such as Metoprolol, which is cardioselective meaning it specifically targets the cardiovascular system. This drug slows down the heartbeat which lowers the stress on the heart. Propranolol, is non-selective and affects all of the sympathetic nervous system.
NSAIDs, such as aspirin and ibuprofen may reduce the blood pressure lowering ability of beta blockers. Taking phenobarbital (barbiturate) along with some beta blockers may also reduce their effectiveness. For those with heart problems, beta blockers should not be stopped suddenly but must be tapered off. Beta blockers are taken orally or injected intravenously.