Pharmacology: Drug Binding and Action

Drug Binding and Action

• Affinity refers to a drug's ability to bind to a receptor, which is crucial for its function.
• Intrinsic activity indicates a drug's capability to produce a biological effect once it binds to a receptor.

Drug Classification Based on Intrinsic Activity

• Agonist: Drugs that bind to receptors and activate them, producing a maximum response (+1).
• Partial Agonist: Drugs that bind to receptors and activate them but produce a less than maximum response (between 0 and +1).
• Inverse Agonist: Drugs that bind to receptors and induce an opposite effect compared to agonists (-ve).
• Antagonist: Drugs that do not activate receptors but block or interfere with the action of agonists, having no intrinsic activity themselves (0).

Summary of Intrinsic Activities

• Maximum intrinsic activity (Agonist): Full response achieved when binding.
• Submaximum intrinsic activity (Partial Agonist): Weaker response compared to full agonists.
• Opposite action (Inverse Agonist): Reverses the effects of agonists.
• No intrinsic action (Antagonist): Prevents receptor activation without direct activation.

Explore the key concepts of drug binding and action in pharmacology. This quiz covers drug affinity, intrinsic activity, and classifications such as agonists, partial agonists, inverse agonists, and antagonists. Test your understanding of how these classifications affect drug function and response.