Pharmacology Principles PHCO 310

Overview of Pharmacology

• Pharmacology stems from Greek words: "pharmakos" (drug) and "logos" (study).
• Defined as the study of substances interacting with living systems through chemical processes, regulating body functions.

Educational Background

• PhD in Pharmacology from The University of Manchester (Apr 2023).
• MSc in Drug Discovery and Pharmaceutical Sciences from University of Nottingham (Dec 2016).
• BSc in Pharmacy from Umm Al-Qura University, KSA (Jun 2013).

Research Interests

• Focus on nuclear hormone receptors in breast cancer progression.
• Interested in cancer metabolism, epithelial-mesenchymal transition (EMT), and metastasis.

Lecture Objectives

• Identify general principles of pharmacology, including history and drug nature.
• Compare various phases of drug development.
• Define and interpret pharmacokinetics parameters.
• Understand principles of pharmacodynamics.
• Recognize drug-drug interactions and adverse effects.

Nature of Drugs

• Drugs are substances for preventing, curing, or alleviating medical conditions.
• Types of drugs include inorganic ions, organic molecules, peptides, proteins, nucleic acids, lipids, and carbohydrates.
• Unique molecular characteristics are required for selective receptor binding.

Ideal Drug Characteristics

• Effectively treats or prevents conditions.
• Produces rapid results at low doses with minimal side effects.
• Convenient administration, often orally and infrequent dosing.
• Affordable and accessible with quick elimination from the body.
• Should not interact negatively with other medications or food.

Drug Development Process

• Safety and efficacy assessments critical before patient use.
• Preclinical phase includes laboratory work lasting 3-5 years.
• Clinical phases:
  • Phase 1: 20-100 healthy participants assess dosage and pharmacokinetics.
  • Phase 2: 100-300 patients with diseases evaluate efficacy and safety.
  • Phase 3: 1000-3000 patients compare efficacy against controls or placebos.
  • Phase 4: Post-marketing surveillance.
• Certain drugs may bypass extensive clinical evidence due to urgent treatment needs (e.g., anticancer drugs).

Pharmacokinetics vs. Pharmacodynamics

• Pharmacokinetics:
  • Concerns what the body does to the drug (ADME: Absorption, Distribution, Metabolism, Excretion).
• Pharmacodynamics:
  • Focuses on what the drug does to the body, including physiological and biochemical effects.

Pharmacokinetics: Absorption

• Effective drugs must reach target cells in adequate amounts.
• Factors affecting passage through membranes include size, ionization, and solubility.
• Bioavailability measures the proportion of drug reaching circulation after absorption.

Mechanisms of Drug Transport

• Diffusion (passive transport): Movement from high to low concentration.
• Active transport: Requires carriers for crossing membranes.

Time-Response Relationship

• Regular medication administration aims to maintain plasma drug levels within therapeutic range.
• Loading dose: High initial dose for quick therapeutic range attainment.
• Maintenance dose: Regular doses to sustain therapeutic concentration.

Recap of Key Pharmacokinetic Terms

• Volume of distribution indicates drug distribution throughout the body.
• Drug-protein binding involves competition for plasma proteins (e.g., albumin).
• Therapeutic drug monitoring ensures drug concentrations remain effective, avoiding toxicity.

Pharmacodynamics: Receptors and Responses

• Agonists activate receptors like endogenous substances; partial agonists provide weaker responses.
• Antagonists block receptors to prevent chemical binding.
• Receptor regulation includes downregulation (diminished response) and upregulation (chronic blocking).

Potency and Efficacy

• Potency refers to the strength of a drug at specific doses; more potent drugs produce effects at lower doses.
• Efficacy is the maximum response achievable from a drug.

Key Recap Questions

• High therapeutic index indicates drug safety.
• Pharmacodynamics describes effects on the body.
• Selective drugs may bind differently to receptors.

Practical Cases

• Comparative analysis of drug effectiveness and responses (e.g., lorazepam vs. diazepam, oxycodone vs. aspirin).