Types of pharmacological effects

There are a variety of types of pharmacological effect, involving the interaction of the drug and receptor to form a complex and thus have an effect, as follows:

• Drug + receptor <-> Drug/receptor complex -> effect:
  • quickly reversible e.g. propranolol, insulin, naloxone
    
    
• Drug + Receptor <-> Drug/Receptor complex -> effect:
  • not easily reversible, for example:
    • digoxin - may need to give Fab of anti Digoxin antibody
    • MAO inhibitors
    • aspirin on platelets - only need very low doses
      
      
• Drug + Receptor <-> Drug/Receptor complex -> effect:
  • DR reversible, but effect prolonged:
    • corticosteroids
    • immunisation
      
      
• Dose response relationships:
  • 75% of adverse drug responses are dose related
    
    
• Steroisomers:
  • warfarin - S and R, t half 32 and 54 respectively; S four times as potent as R form.
  • sotalol - L form is a beta blocker, D form is a class 3 antiarrhythmic