Pharmaceutical drug metabolism plays a pivotal role in determining the efficacy and safety of medications in patients. This article provides a comprehensive overview of the analytical chemistry techniques employed in monitoring drug metabolism. It explores the significance of understanding drug metabolism in personalized medicine and the assessment of drug-drug interactions. The article delves into the various methodologies, such as liquid chromatography-mass spectrometry, nuclear magnetic resonance spectroscopy, and high-performance liquid chromatography, highlighting their applications in quantifying drug metabolites and elucidating metabolic pathways. Additionally, the article discusses the challenges and advancements in this field, emphasizing the potential for enhancing patient care through precise drug monitoring. Overall, this article underscores the critical role of analytical chemistry in optimizing drug therapy and fostering a deeper understanding of pharmaceutical drug metabolism in clinical practice.