| Classification of drug actions |
| The law of mass action in pharmacodynamics |
| Receptor theory of drug action |
| Affinity, association constant and dissociation constant |
| Structural relationships for receptors and ligands |
| Mechanisms of drug-receptor interaction |
| Regulation of drug receptor number and activity |
| Second messenger systems |
| Cyclic AMP (cAMP) |
| Cyclic GMP (cGMP) |
| Calcium, inositol triphosphate and diacylglycerol |