Pharmacology principles provide key understanding that underpins the clinical and research roles of nuclear medicine practitioners in nuclear cardiology. The scope of practice of the nuclear medicine technologist demands knowledge and understanding of indications, contraindications, warnings, precautions, proper use, drug interactions, and adverse reactions for each medication to be used. This article is the fifth in a series of articles that aims to enhance the understanding of pharmacologic principles relevant to nuclear medicine. This article will build on the introductory concepts, terminology, and principles of pharmacology explored in the first 2 articles in the series. Specifically, this article will focus on the pharmacologic principles and complex relationship associated with interventional, adjunctive, and cessation medications in nuclear cardiology. Future articles will address the pharmacology related to the emergency crash cart and contrast medium associated with CT and MRI.