Isoproterenol is a medication used in the treatment of heart-related conditions such as bradycardia, heart block and ventricular fibrillation. However, there are other terms that can be used interchangeably with isoproterenol. For example, isoprenaline, or isoproterenol hydrochloride, is also known as beta-1 adrenergic receptor agonist. Epinephrine, or adrenaline, is another synonym for isoproterenol and is used as a hormone and neurotransmitter within the body. Additionally, norepinephrine, or noradrenaline, is a natural pre-cursor to epinephrine, and functions as a stress hormone in the body. While these terms are synonymous with isoproterenol and share similar pharmacological properties, they may have different therapeutic effects and side effects when used in clinical practice.