1. Introduction to Pharmacology

Pharmacology: the study of interaction of drugs with living systems.

Sub-Disciplines of Pharmacology

• Pharmacodynamics: effects and mechanisms of drug action
  • Drug-Receptor Interactions
  • Dose-Response Relationships
  • Signal Transduction
• Pharmacokinetics: movement of drug throughout the body including:
  • Absorption
  • Distribution
  • Metabolism
  • Excretion
• Pharmacogenetics: genetic factors play a role in the following:
  • Rate of Drug Metabolism
  • Drug-Induced Toxicity
  • Drug-Induced Allergies

Pharmacology and the Pharmacist

Key Questions you should be asking as a Pharmacist:

• Where is the molecular site of action?
• What are the body function changes caused by a drug (pharmacodynamics)?
• What is the relationship between the Dose vs. Effect?
• How does a drug produce its effect?
• What is the fate of the drug once it enters the body (pharmacokinetics)?
• What is the interplay between genetic makeup and drug response?

Example: Beta 1 Blocker: Metoprolol Succinate (oral)

Drug Action: selective binding to cardiac muscle beta 1 adrenergic receptors that respond to norepinephrine (at higher doses, also inhibits bronchial and vascular smooth muscle by acting on beta 2 adrenergic receptors) to inhibit the binding of norepinephrine.

Drug Effect: reduced inotropic effect (contractility) and chronotropic effect (heart rate)

Fate of the Drug (pharmacokinetics): 12% protein binding and distribution 5.6 L/kg: hepatic metabolism (CYP2D6 mainly): <5% renal excretion: t_1/23-7 hours