Beetaadrenergisten

Beetaadrenergisten, or beta-adrenergic agents, are pharmacological compounds that interact with beta-adrenergic receptors (β1, β2, β3) of the sympathetic nervous system. They can be divided into agonists, which activate the receptors, and antagonists, commonly known as beta-blockers, which inhibit receptor activation.

Receptors and effects: β1 receptors are predominantly in the heart and increase heart rate and contractility when stimulated. β2 receptors are abundant in the lungs and vascular smooth muscle, where activation leads to bronchodilation and vasodilation. β3 receptors are involved in adipose tissue metabolism, influencing lipolysis. The clinical effects of beta-adrenergic agents depend on the receptor subtype they target and their selectivity.

Beta-adrenergic agonists: These drugs activate beta receptors. They are used as bronchodilators in asthma and chronic obstructive pulmonary disease (COPD) and include agents such as salbutamol (albuterol), terbutaline, and long-acting options like formoterol and salmeterol. Some agents, like isoproterenol, can stimulate the heart in certain acute settings. The choice of agent depends on desired β1 vs β2 activity and duration of action.

Beta-adrenergic antagonists (beta-blockers): These drugs block beta receptors and are widely used to treat cardiovascular conditions such as hypertension, angina, arrhythmias, and heart failure. Examples include propranolol (non-selective), metoprolol and atenolol (β1-selective), and carvedilol (non-selective with additional α-blockade). Selectivity and pharmacokinetics influence therapeutic use and side effects.

Side effects and considerations: Common issues include tachycardia and tremor with agonists, and bronchospasm or wheezing with non-selective beta-blockers in asthma or COPD. Metabolic effects and masking of hypoglycemia can occur with some agents. Clinical choice takes receptor selectivity, route of administration, and patient comorbidities into account.

See also: Adrenergic receptors, Beta-adrenergic receptor subtypes, Adrenergic agonists, Beta-blockers.