Pearls for Betablockers

By: Maged Taman

Beta blockers are one of the miracles of drug treatment in medicine. They treat many medical conditions with careful use of them most people who are on are doing well. These are some of the medical pearls with us of betablockers.

1- Any patient after with heart attack should be on unless there is a serious contraindication. Patients with angina, heart attacks and some arrhythmia will benefit much from the beta blockers.

2- For people who do not have angina or coronary artery disease there use in primary prevention is not demonstrated. In fact "No evidence exists that beta-blockers prevent first episodes of cardiovascular events in patients with hypertension, and in some trials, outcomes were worse with beta-blockers than with antihypertensive drugs of other classes." http://www.ccjm.org/content/76/9/533.full "However, newer beta-blockers with vasodilatory properties should be considered in cases of uncontrolled or resistant hypertension, especially in younger patients". further studies needed to see if they would prevent coronary events in these patients.

3- Beta 1 selective class is usually prescribed like metoprolol.

4- Patients with non serious airway disease are commonly able to tolerate small doses of beta1 selective. Though you need to start by lowest dose possible like lopressor 12.5 mg daily and warn patient to report worsening of lung disease.

5- Some of Beta blockers are good for both diastolic and systolic congestive heart failure. Metoprolol and carvedilol are particularly effective in systolic heart failure after patient becomes non symptomatic with diuretic and ACE-inhibitors.

6- If patient to develop fatigue in betablcoker you can give the dose at night time which usually cause the fatigue to subside.

7- If patient to develop night mares, depression or hallucination switch to a hydrophilic beta-blocker atenolol instead of lipophilic agents metoprolol and propranolol.

8- Beta blockers protect against social anxiety like with musicians, some sports and new speakers. Propranolol is classically used in these conditions.

9- Beta blockers must not be used in the treatment of cocaine, amphetamine, or other alpha adrenergic stimulant overdose. The blockade of only beta receptors while alpha adrenergic is stimulated by the cocaine and amphetamine will cause increased hypertension, reduced coronary blood flow, and put patient at risk of myocardial infarction.

10- Similar effect to above can occur in giving betablockers to patients with pheochromocytoma an endocrine tumor that secrete catecholamine that stimulate alphadrenergic receptors. Thus alpha blockade is used with drus like Phenoxybenzamine (Dibenzyline) 10 mg PO b.i.d. and increased by 10–20 mg every 2 days as needed to control BP and paroxysmal spells (average dose is 0.5–1.0 mg/kg/d, max dose is 300–400 mg/d). This is followed by inderal to control heart rate start at low dose 10 mg every 6 hours and increase dose gradually.

11- Propranolol is the only beta blocker indicated for control of tremor, portal hypertension and esophageal variceal bleeding. It is used in conjunction with α-blocker therapy in phaeochromocytoma see above.