Overview of Pharmacology and Drug Classification

Overview of Pharmacology

• Definition: The study of drugs, their properties, effects, and mechanisms of action.
• Branches:
  • Pharmacodynamics: Effects of drugs on the body.
  • Pharmacokinetics: Absorption, distribution, metabolism, and excretion of drugs.

Drug Classification

• By Source:
  • Natural (plants, animals, minerals)
  • Synthetic (chemically manufactured)
• By Therapeutic Use:
  • Analgesics (pain relief)
  • Antibiotics (infection treatment)
  • Antihypertensives (blood pressure regulation)
• By Mechanism of Action:
  • Agonists (activate receptors)
  • Antagonists (block receptors)

Drug Development Process

1. Discovery: Identifying potential therapeutic compounds.
2. Preclinical Testing: Laboratory and animal studies to assess safety and efficacy.
3. Clinical Trials:
   • Phase I: Safety in small groups.
   • Phase II: Efficacy in larger groups.
   • Phase III: Larger populations, comparison to standard treatments.
4. Regulatory Approval: Review by regulatory bodies (e.g., FDA).
5. Post-Market Surveillance: Monitoring long-term effects and safety.

Pharmacokinetics

• Absorption: How drugs enter the bloodstream.
• Distribution: Movement of drugs throughout the body.
• Metabolism: Chemical alteration of drugs, primarily in the liver.
• Excretion: Removal of drugs from the body, primarily via kidneys.

Pharmacodynamics

• Mechanism of Action: How drugs produce their effects at the cellular level.
• Dose-Response Relationship: Relationship between drug dosage and effect.
• Therapeutic Index: Ratio between the toxic and therapeutic dose.

Drug Interactions

• Types:
  • Synergistic: Combined effect greater than individual effects.
  • Antagonistic: One drug reduces the effect of another.
• Considerations: Patient history, current medications, food interactions.

Adverse Effects

• Types:
  • Side effects: Undesired but predictable effects.
  • Allergic reactions: Immune responses that can be severe.
  • Toxicity: Harmful effects from overdose or prolonged use.

Key Concepts

• Half-Life: Time taken for the drug concentration to reduce by half; affects dosing frequency.
• Bioavailability: Portion of a drug that enters circulation when introduced into the body.
• Agonist vs. Antagonist: Agonists activate receptors; antagonists block them.

Clinical Considerations

• Patient Variability: Genetics, age, sex, weight, and health status can affect drug response.
• Personalized Medicine: Tailoring drug therapy to individual patient characteristics.

Common Terms

• Prescription: Written order for a specific medication.
• Over-the-counter (OTC): Medications available without a prescription.
• Pharmacovigilance: Monitoring the effects of drugs post-approval to ensure safety.

Overview of Pharmacology

• Pharmacology: Focuses on drug properties, effects, and mechanisms of action.
• Pharmacodynamics: Studies how drugs affect biological systems.
• Pharmacokinetics: Examines drug absorption, distribution, metabolism, and excretion.

Drug Classification

• Source:
  • Natural: Derived from plants, animals, and minerals.
  • Synthetic: Created through chemical processes.
• Therapeutic Use:
  • Analgesics: Medications for pain relief.
  • Antibiotics: Drugs aimed at treating infections.
  • Antihypertensives: Medications used to manage blood pressure.
• Mechanism of Action:
  • Agonists: Substances that activate receptors to elicit a biological response.
  • Antagonists: Substances that inhibit or block receptor activity.

Drug Development Process

• Discovery Phase: Involves identifying compounds that may have therapeutic benefits.
• Preclinical Testing: Safety and efficacy are evaluated through lab and animal studies.
• Clinical Trials:
  • Phase I: Assess safety in a small group of healthy volunteers.
  • Phase II: Evaluate efficacy in larger patient groups.
  • Phase III: Test on larger populations and compare with standard treatments.
• Regulatory Approval: Required evaluation by regulatory authorities, such as the FDA.
• Post-Market Surveillance: Continuous monitoring for long-term safety and adverse effects.

Pharmacokinetics

• Absorption: Process of drug entry into the bloodstream.
• Distribution: Dispersion of the drug throughout the body's tissues and fluids.
• Metabolism: Biochemical modification of drugs, mainly in the liver.
• Excretion: Elimination of drugs from the body, primarily through the kidneys.

Pharmacodynamics

• Mechanism of Action: Defines how drugs exert their effects on cells.
• Dose-Response Relationship: Illustrates the correlation between drug dose and its effect.
• Therapeutic Index: The ratio indicating the safety margin between effective and toxic doses.

Drug Interactions

• Types:
  • Synergistic: Combined drugs produce a greater effect than individually.
  • Antagonistic: One drug diminishes the effect of another.
• Considerations: Important to assess patient history, current medications, and food interactions.

Adverse Effects

• Types:
  • Side effects: Unwanted effects that are predictable.
  • Allergic reactions: Immune responses that can vary in severity.
  • Toxicity: Detrimental effects resulting from excessive dosing or prolonged use.

Key Concepts

• Half-Life: Indicates the time required for drug concentration in the body to decrease by half; impacts frequency of administration.
• Bioavailability: The fraction of the administered drug that reaches systemic circulation.
• Agonist vs. Antagonist: Agonists activate receptors; antagonists impede receptor function.

Clinical Considerations

• Patient Variability: Factors such as genetics, age, sex, weight, and health status impact individual drug responses.
• Personalized Medicine: Customizing treatment plans based on unique patient characteristics.

Common Terms

• Prescription: A documented directive for a specific medication.
• Over-the-Counter (OTC): Medications accessible without a prescription.
• Pharmacovigilance: The ongoing process of monitoring drug effects after approval to ensure continued safety.

This quiz covers key concepts in pharmacology, including the study of drug properties, effects, and mechanisms of action. Explore drug classification by source, therapeutic use, and mechanisms, alongside the stages of drug development from discovery to clinical trials.