Pharmacology Lecture Notes

Definition

• Pharmacology is the study of medications or chemical compounds interacting with living systems (molecules, cells, tissues, organisms) to produce effects.

Drug Development Process

1. Discovery
   • Identifying a candidate compound as a potential therapeutic agent for a specific disease.
2. Pre-clinical Research
   • Testing the compound on cell cultures and animals to identify potential harm.
3. Clinical Development
   • Clinical trials on humans to assess safety and effectiveness.

Clinical Trials Phases

• Phase 1: Tests safety on a small group of healthy individuals.
• Phase 2: Tests efficacy and dose response on individuals with the disease.
• Phase 3: Compares new medication to standard treatments in a larger group.
• Phase 4: Post-market safety surveillance for long-term or rare side effects.

Naming of Medications

• Chemical Name: Describes chemical structure, used in scientific studies (e.g., N-acetyl-p-amino phenol).
• Generic Name: Shortened version, used by health professionals (e.g., Paracetamol or Acetaminophen).
• Brand Name: Given by pharmaceutical companies (e.g., Panadol or Tylenol).

Pharmacokinetics

• Refers to the movement/modification of medications in the body.
• ADME: Absorption, Distribution, Metabolism, Excretion.

Pharmacodynamics

• Refers to the effects of medications on the body.
• Interaction with receptors or proteins on/in cells leading to cellular changes.
• Ideal medications have therapeutic effects with minimal side effects.

Therapeutic Index

• Ratio of toxic dose to effective dose.
• Calculated as TD50/ED50.
• Larger index = safer medication.
• Medications with low index (e.g., Warfarin, Lithium) require monitoring.

Drug Interactions

• Pharmacokinetic Interactions: Affect absorption, distribution, metabolism, excretion of drugs.
• Pharmacodynamic Interactions: Drugs affect each other's effects (synergistic or antagonistic).

Recap

• Drug development: Discovery, Preclinical, Clinical steps.
• Medication Naming: Chemical, Generic, Brand.
• Pharmacokinetics: Body effects on drugs.
• Pharmacodynamics: Drug effects on the body.
• Therapeutic Index: Safety measure.
• Drug interactions can occur at pharmacokinetic and pharmacodynamic levels.