Untitled Quiz

Introduction to Clinical Pharmacology

• Goal: Optimize drug therapy and minimize adverse effects
• Paracelsus (16th century): Emphasized the importance of dose in determining toxicity - "All things are poisons, and nothing is without poison; only the dose makes a thing not a poison."
• Pharmacology: Foundation of pharmacotherapeutics (treating diseases with drugs).
  • Overlap with Pharmacy: The science of drug production.

Areas of Clinical Pharmacology

• Molecular Pharmacology: Focuses on how drugs interact with molecules within the body.
• Population Pharmacology: Uses randomized clinical trials, observational studies (case-control), and pharmacoepidemiology to examine the effect of drugs in different populations.
• Pharmacovigilance: Monitors the safety of drugs after they have been released for use (adverse effects).
• Pharmacoeconomics: Evaluates the cost-effectiveness of drug treatments.
• Social Factors: Considers how social factors impact drug therapy.
• Medicine Policy: Examines the regulations and policies surrounding the use of drugs.

Focus Areas of Clinical Pharmacology

• Pharmacodynamics: How drugs affect the body (mechanism of action).
• Pharmacokinetics: How the body handles a drug (ADME - absorption, distribution, metabolism, excretion).
• Therapeutic evaluation:
  • Determining the value of a drug.
  • Identifying the optimal use of a drug.
  • Implementing formal therapeutic trials.
  • Conducting surveillance studies to assess both efficacy and safety (adverse effects) using pharmacoepidemiology and pharmacovigilance.

Control of Drug Use

• Rational Prescribing & Formularies: Ensuring appropriate drug usage and cost control.
• Official Regulation of Medicines: Setting standards for drug safety, efficacy, and quality by government agencies.
• Social Aspects of Medicine Use & Misuse: Addressing issues like substance abuse and non-compliance.
• Pharmacoeconomics: Evaluating the cost-effectiveness of drug treatments.
• Unacceptable Risk: Risks that are unjustifiable or outweigh the potential benefits.
• Acceptable Risk: Risks that are deemed acceptable given the benefits of a drug, usually in the context of a serious disease.
• Negligible Risk: Risks that are considered insignificant or highly unlikely.

Uses of Drugs

• Intermittent Use: To cure a specific condition like bacterial or parasitic infections, anesthesia.
• Suppression or Control: Drugs can suppress the symptoms of diseases like hypertension, diabetes, asthma, or joint diseases.
• Prevention:
  • Primary Prevention: Preventing a disease entirely, like using a malaria prophylactic or a contraceptive pill.
  • Secondary Prevention: Aiming to prevent complications of a disease, like preventing heart failure in patients who have had a heart attack.

Factors in Responsible Drug Use

• Better knowledge of the disease: Understanding the nature of the disease to choose the appropriate drug.
• Site-specific effects: Considering how a drug will affect a particular part of the body.
• Site-specific delivery: Delivering a drug directly to a target area to minimize side effects.
• Informed, careful, and responsible prescribing: Providing patients with clear information about the drug and monitoring their response.

Drug Risk Assessment

• Risk assessment is different for life-threatening diseases compared to mild diseases: The potential benefits of a drug may outweigh the risks in a serious disease.

Pharmacology Terms

• Affinity: The strength of the attraction between a drug and its receptor.
• Selectivity: A drug's tendency to bind to one target receptor over another.
• Agonist: A drug that binds to a receptor and activates it, resulting in a biological response.
  • Full Agonist: Produces the maximum possible response for that specific receptor.
  • Partial Agonist: Produces a response less than the maximum even at high concentrations.
• Bioavailability: The percentage of a drug that reaches the systemic circulation after administration (often compared to intravenous administration which has 100% bioavailability).
• Therapeutic Efficacy: A drug's ability to produce a desired effect on a biological target.
• First-Pass Effect: The metabolism of a drug by the liver and intestines before it reaches systemic circulation, affecting bioavailability.
• Half-Life: The time it takes for the concentration of drug in the body to decrease by half.
• Potency: The amount of a drug required to produce a specific effect (a higher potency means a lower dose is needed).
• Synergy: The combined effect of two drugs is greater than the sum of their individual effects.
• Desensitization: A decrease in response to a drug after repeated or continuous administration.
• Tachyphylaxis: A more rapid and profound decrease in response to a drug after repeated doses over a short time.
• Tolerance: A gradual decrease in response to a drug over time, requiring higher doses to achieve the same effect.
• Therapeutic Index: A measure of the relative safety of a drug, reflecting the ratio between the dose that causes a therapeutic effect and the dose that causes toxicity.