How is "onset of action" defined in pharmacology?

Onset of action refers to the time it takes for a drug to begin to produce its therapeutic effects after administration. This concept is crucial in pharmacology because it helps healthcare providers understand how quickly a medication will work in the body. The onset of action can vary widely among different drugs due to factors such as the route of administration, the drug’s formulation, and the individual’s unique physiology.

Understanding onset is essential for effective patient care, especially in situations requiring rapid symptom relief or precise timing of medication administration, such as in pain management or critical care settings. In contrast, peak concentration is related to when the drug reaches its maximum effect, metabolism pertains to how the body processes the drug, and duration describes how long the drug continues to exert its effects in the body. All these concepts are interconnected but serve different roles in pharmacological practice.