Types of pharmacologically active agent

Question 1

What are the three main pathways by which drugs can act on cells of the body?

Answer 1

1. Acting via receptors (Endogenous agents or Exogenous agents)
2. Activating or inhibiting enzymes
3. Acting on membrane transporters or ion channels

Question 2

What is a drug?

Answer 2

A chemical compound that, when applied to a biological system, alters that biological system’s function in a specific manner

Question 3

What are the three types of cell surface receptor? Give examples for each.

Answer 3

Ligand-gated ion channels (e.g. nAChR)
G-protein coupled receptors (e.g. mAChR, alpha/beta adrenergic receptors)
Enzyme-linked receptors (e.g. Cytokine receptors, insulin receptor) - can be linked to an enzyme (usually kinase) or function as an intrinsic enzyme itself