The understanding of key principles in pharmacology is essential to the clinical and research nuclear medicine practitioner. The scope of practice of the nuclear medicine technologist requires understanding of the indications, contraindications, warnings, precautions, proper use, drug interactions, and adverse reactions for interventional and adjunctive medications. This article is the companion to the third 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 previous articles in the series. Specifically, this article will focus on the pharmacologic principles associated with less commonly used interventional medications and adjunctive medications encountered in general nuclear medicine practice. Future articles will address the pharmacology related to nuclear cardiology, the emergency crash cart, and contrast media associated with CT and MRI.