What does pharmacodynamics study?

Pharmacodynamics focuses on the effects that drugs have on the body, including how they interact with biological systems to produce their effects. This branch of pharmacology examines the biochemical and physiological effects of drugs, including their mechanism of action, the relationship between drug concentration at the site of action, and the ultimate biological response. Understanding pharmacodynamics is essential for determining the therapeutic effects and side effects of medications, allowing healthcare professionals to optimize drug therapy for patients.

The other options pertain to different aspects of pharmacology. The absorption of drugs concerns how they enter the bloodstream, metabolism relates to how drugs are chemically altered in the body, and excretion involves the elimination of drugs and their byproducts. While these factors are crucial for understanding the overall pharmacological effects of a drug, they fall under the broader category of pharmacokinetics, which deals with the movement of drugs in the body rather than their specific effects.