What Is Isoproterenol?
Isoproterenol, also known as isoprenaline, is a drug that possesses an isopropylamine or catechol backbone. It is primarily used to treat atrioventricular block, bradycardia, and bronchial asthma due to its ability to act on beta-adrenergic receptors without affecting alpha-adrenergic receptors.
Uses of Isoproterenol
Isoproterenol selectively binds to β-adrenergic receptors, stimulating the sympathetic nervous system. This activation strengthens the heart’s electrical signals, increasing heart rate and dilating peripheral blood vessels, which is beneficial in treating cardiac disorders like arrhythmia. It also relaxes smooth muscles, making it an effective bronchodilator for asthma and bronchospasm treatment.
Properties of Isoproterenol
Isoproterenol is a white powder or crystalline solid at room temperature. It has a chemical formula of C11H17NO3, a molecular weight of 211.258 g/mol, and a half-life of approximately 2 minutes post-absorption. The catecholamine structure of isoproterenol makes it a neurotransmitter mimetic.
Other Information on Isoproterenol
1. Effects of Isoproterenol
As a trace amine-associated receptor 1 agonist, isoproterenol’s pharmacodynamic effects are similar to endogenous trace amines. Its nonselective circulatory system effects result from stimulation of beta1 and beta2 receptors, causing vasodilation and influencing blood pressure.
2. Structure-Activity Relationship of Isoproterenol
The isopropyl amino group in isoproterenol contributes to its selectivity for β-receptors, while the catechol hydroxyl group maintains sensitivity to metabolic enzymes.
3. Isoproterenol in Asthma Treatment
Isoproterenol, as an agonist of sympathetic β1 and β2 receptors, was widely used in asthma treatment before the development of β2-selective agonists like salbutamol.
4. Side Effects of Isoproterenol
Significant side effects of isoproterenol include a decrease in serum potassium levels and myocardial ischemia, particularly with the injectable form.
5. Related Substances to Isoproterenol
Catecholamines in isoproterenol serve as the backbone for various biological substances such as dopamine, levodopa, adrenaline, and noradrenaline.