Nursing Pharmacology
Comprehensive Study Reference for Nursing Students
Introduction
Pharmacology involves the study of drugs — their origins, mechanisms, therapeutic
applications, and potential side effects — and how they interact with biological systems. For
nurses, a solid grasp of pharmacological principles is critical to ensuring safe drug
administration, detecting adverse reactions early, and supporting informed patient care.
1. Pharmacokinetics — How the Body Handles Drugs
Pharmacokinetics refers to the journey a drug takes through the body, often summarized using
the ADME framework:
• Absorption — The process by which a drug moves from the site of administration into
systemic circulation.
• Distribution — Once absorbed, the drug travels via blood to various body
compartments, tissues, and organs.
• Metabolism — The body converts drugs — primarily in the liver — into metabolites that
can be more easily excreted.
• Excretion — The final elimination of drugs and their metabolites from the body, mainly
through renal filtration, but also via bile, expired air, sweat, or saliva.
2. Pharmacodynamics — How Drugs Affect the Body
Pharmacodynamics examines the biological and biochemical effects of drugs and their
mechanisms of action within the body:
• Mechanism of Action — Describes how a drug exerts its effect — typically by binding to
specific receptors, enzymes, or cellular targets.
• Dose–Response Relationship — Defines the correlation between the quantity of drug
administered and the magnitude of the resulting effect.
• Therapeutic Index (TI) — Expresses the margin of safety of a drug; a higher TI indicates
greater safety. Calculated as the ratio of toxic dose to effective dose.
• Agonists — Substances that bind to and activate receptors, mimicking or enhancing
normal physiological responses.
• Antagonists — Substances that occupy receptor sites without activating them, thereby
blocking natural or drug-induced responses.
Comprehensive Study Reference for Nursing Students
Introduction
Pharmacology involves the study of drugs — their origins, mechanisms, therapeutic
applications, and potential side effects — and how they interact with biological systems. For
nurses, a solid grasp of pharmacological principles is critical to ensuring safe drug
administration, detecting adverse reactions early, and supporting informed patient care.
1. Pharmacokinetics — How the Body Handles Drugs
Pharmacokinetics refers to the journey a drug takes through the body, often summarized using
the ADME framework:
• Absorption — The process by which a drug moves from the site of administration into
systemic circulation.
• Distribution — Once absorbed, the drug travels via blood to various body
compartments, tissues, and organs.
• Metabolism — The body converts drugs — primarily in the liver — into metabolites that
can be more easily excreted.
• Excretion — The final elimination of drugs and their metabolites from the body, mainly
through renal filtration, but also via bile, expired air, sweat, or saliva.
2. Pharmacodynamics — How Drugs Affect the Body
Pharmacodynamics examines the biological and biochemical effects of drugs and their
mechanisms of action within the body:
• Mechanism of Action — Describes how a drug exerts its effect — typically by binding to
specific receptors, enzymes, or cellular targets.
• Dose–Response Relationship — Defines the correlation between the quantity of drug
administered and the magnitude of the resulting effect.
• Therapeutic Index (TI) — Expresses the margin of safety of a drug; a higher TI indicates
greater safety. Calculated as the ratio of toxic dose to effective dose.
• Agonists — Substances that bind to and activate receptors, mimicking or enhancing
normal physiological responses.
• Antagonists — Substances that occupy receptor sites without activating them, thereby
blocking natural or drug-induced responses.
