Beta Blockers Essay

Beta blockers (β-blockers or BBs) were invented and designed by Sir James Black, who was a Nobel Prize winning scientist. Black designed beta blockers to counteract stimulated adrenergic effects. He demonstrated that, by blocking the cardiac beta-receptors, these agents could cause inhibitory effects on the sinus node (chronotropic effect), atrioventricular node (dromotropic effect), and on myocardial contractility (inotropic effect).1
It is important to note that not all beta receptors (β-receptors) are the same. There are two clinically targeted types of beta receptors in the human body: beta 1 (β1) receptors which are mostly located on the cardiac muscle itself and when stimulated increase contractility by opening electro-physiological
In fact many practice guidelines advise against this, or counter-indicate BBs with COPD, for fear of the antagonistic actions of BBs will counteract the beta agonist actions of the patient’s COPD medication resulting in bronchospasms and other adverse effects. There has been a lot of controversial evidence about this topic, however, recent emerging studies have shown the BBs CVD benefits outweigh the risks associated with COPD. A compilation of retrospective studies show the benefits of beta blockade in this group appear to outweigh any potential risk of side effects according to the available evidence1. CVD and COPD are very common co-morbidities seen in clinical practice patient populations, in particular myocardial infarctions (MI) and COPD. Furthermore, the most common comorbid conditions associated with withholding BBs in elderly patients after myocardial infarction (MI) are COPD and asthma…many patients are diagnosed and treated for COPD with no objective evidence, such as pulmonary function tests or specialist assessment, to confirm the diagnosis, as recommended by most thoracic societies. This may indicate that a significant number of patient are deprived the prognostic benefits of using
A group of recent studies show BBs are well tolerated in patients with cardiac disease and concomitant COPD with no evidence of worsening of respiratory symptoms or forced expiratory volume (FEV1) and the safety of BBs in patients with COPD has been demonstrated, but their use in this group of patients remains low. The cumulative evidence from trials and meta-analysis indicates that cardioselective BBs should not be withheld in patients with reactive airway disease or COPD.1 This evidence leads us to believe that placing a COPD patient with a larger risk of CVD complications would benefit from a cardioselective beta blocker. In fact, large meta-analyses were published where randomized, blinded, placebo-controlled trials that studied the effects of cardioselective BBs on FEV1, symptoms, and the use of inhaled β2-agonists in patients with reactive airway disease were selected, of which, there were 19 single dose treatment studies and 10 continued treatment studies. The outcomes measures were the change in FEV1 from baseline, the number of patients with respiratory symptoms, and the use of inhaled β2-agonists with active treatment compared with placebo. The results were that no significant treatment effect in terms of FEV1 was found in patients with concomitant COPD, whether single doses (change in FEV1, −5.28% [CI, −10.03% to