Which beta (beta blocker) causes the least bradycardia?

From the Guidelines

Bisoprolol is the beta blocker that causes the least bradycardia among commonly used agents. When considering the management of stable angina pectoris, beta-blockers are effective in reducing anginal symptoms and ischemia by reducing heart rate and contractility, and by reducing blood pressure 1. Beta-1 selective agents, such as bisoprolol, metoprolol, and atenolol, are preferred due to their advantages concerning side-effects and precautions when compared with non-selective beta-blockers.

Key characteristics of bisoprolol include:

• High cardioselectivity, which means it primarily targets beta-1 receptors in the heart while having less impact on beta-2 receptors elsewhere in the body
• Favorable pharmacokinetic profile, allowing for more predictable blood levels and fewer peak-related side effects
• Reduced bradycardic effects compared to other agents like metoprolol or atenolol, especially at low doses (e.g., 2.5-5 mg daily)
• Effective anti-anginal and anti-ischaemic effects, which are additive to those of calcium channel blockers (CCBs) in many patients 1.

For patients with concerns about bradycardia, starting with the lowest effective dose and gradually titrating upward while monitoring heart rate is recommended. Patients with baseline bradycardia, sick sinus syndrome, or high-degree AV blocks should use any beta blocker with caution, regardless of its relative bradycardic potential. Overall, bisoprolol's pharmacological profile makes it a suitable option for patients who require beta-blockade with minimal heart rate reduction effects.

From the FDA Drug Label

The most common adverse reactions that led to discontinuation of nebivolol tablets were headache (0.4%), nausea (0.2%) and bradycardia (0. 2%) Table 1 lists treatment-emergent adverse reactions that were reported in three 12-week, placebo-controlled monotherapy trials involving 1597 hypertensive patients treated with either 5 mg, 10 mg, or 20-40 mg of nebivolol tablets and 205 patients given placebo and for which the rate of occurrence was at least 1% of patients treated with nebivolol and greater than the rate for those treated with placebo in at least one dose group. Cardiac Disorders Bradycardia 0 0 0 1

Nebivolol causes the least bradycardia, with an incidence of 0-1% in clinical trials 2.

• The incidence of bradycardia with nebivolol is lower compared to other beta blockers, such as bisoprolol, which lists bradycardia as a common sign of overdosage 3.
• However, direct comparison between nebivolol and bisoprolol is not possible based on the provided drug labels, as the incidence of bradycardia is not directly reported for bisoprolol in a similar clinical trial setting.

From the Research

Beta Blockers and Bradycardia

• Beta blockers are known to cause bradycardia as a side effect, but the extent of this effect can vary depending on the specific medication 4, 5.
• Studies have shown that beta blockers with intrinsic sympathomimetic activity (ISA) tend to cause less bradycardia than those without ISA 4, 6, 7.
• Pindolol, a beta blocker with ISA, has been found to decrease resting heart rate to a lesser extent than propranolol, a beta blocker without ISA 4, 5.
• The presence of ISA in beta blockers can result in less resting bradycardia and less reduction in cardiac output, making them a potentially better option for patients who are prone to bradycardia 6, 7.

Comparison of Beta Blockers

• Pindolol has been shown to cause less bradycardia than propranolol, with a decrease in resting heart rate of only 0.13 beats/min compared to 7.5 beats/min for propranolol 4.
• Other beta blockers with ISA, such as acebutolol and nebivolol, may also cause less bradycardia than those without ISA 8, 7.
• The choice of beta blocker should be based on individual patient characteristics and medical history, taking into account the potential for bradycardia and other side effects 8, 6.

Clinical Implications

• Beta blockers with ISA may be a better option for patients with conditions that make them prone to bradycardia, such as sinus bradycardia or sick sinus syndrome 6.
• The use of beta blockers with ISA may also be beneficial in patients with hypertension, as they can help to reduce blood pressure while minimizing the risk of bradycardia 6, 7.
• Further research is needed to fully understand the effects of beta blockers with ISA and to determine their optimal use in clinical practice 8, 7.