Principles of Pharmacology
1.1 Pharmacology Introduction
Open Resources for Nursing (Open RN)
Learning Objectives
- Identify and describe the processes of pharmacokinetics
- Apply principles of evidence-based practice to identify pertinent information related to drugs
- Consider pharmacodynamic differences across the lifespan
- Differentiate among prescription drugs, over-the-counter drugs, herbals, and dietary supplements
Key Terms
Safe medication administration is a vital component of the nursing role. Each day it is common for nurses to make clinical judgments regarding the safety, appropriateness, and effectiveness of the medications administered to their clients.
Examples of decisions that a nurse might make during client care include:
- Is my client’s heart rate within the correct range to receive this beta-blocker medication?
- Does my client have adequate renal function prior to administering this dose of antibiotic?
- Is this pain medication effective in controlling my client’s discomfort?
In order to make safe medication administration decisions, the nurse must have a strong understanding of pharmacology. Symptom management, physical recovery, and individual well-being can be strongly connected to the use of medications in a client’s treatment plan. Before a nurse reviews a medication order, checks a medication administration record, or administers a medication, it is important to have a foundational understanding of how medications work within the human body.
Nurses should understand the key components of pharmacology
- Pharmacotherapeutics: The clinical purpose or reason for the medication
- Pharmacokinetics: The movement of the drug through the body
- Pharmacodynamics: The physiological response of the body to the drug.
These next sections will introduce pharmacokinetics and pharmacodynamics. Future chapters of this textbook will focus on the pharmacotherapeutics of specific drug classifications.
- Health Information Management. (2021). Glossary of Terms - Client. http://www.himconnect.ca/meet-him/faqs/glossary-of-terms ↵
The first stage of pharmacokinetics: medications enter the body and travel from the site of administration into the body's circulation.
The length of time that a medication is available within the body and producing its desired therapeutic effect.
The study of how people's genes affect their response to medicines.
An unintended pharmacological effect that occurs when a medication is administered correctly.
The maximum effect of which the drug is capable.
The study of how the body absorbs, distributes, metabolizes, and eliminates drugs.
The strength of binding between drug and receptor.
The final stage of pharmacokinetics; process by which the body eliminates waste or excess.
The clinical purpose or reason for the medication
A drug which binds to its "receptor" and produces its characteristic effect.
The breakdown of orally administered drugs in the liver and intestines.
The science dealing with actions of drugs on the body.
A molecule that prevents the action of other molecules, often by competing for a cellular receptor; opposite of agonist.
The rate at which 50% of a drug is eliminated from the bloodstream.
The drug dose required to produce a specific intensity of effect.
The ability of a drug or other chemical to be taken up by the body and made available in the tissue where it is needed.
How a medication works at a cellular level within the body.
How readily the drug targets specific cells to produce an intended therapeutic effect.
A nearly impenetrable barricade that is built from a tightly woven mesh of capillaries cemented together to protect the brain from potentially dangerous substances such as poisons or viruses.
The breakdown of a drug molecule via enzymes in the liver (primarily) or intestines (secondarily).
The effect of a drug, other than the desired effect, sometimes in an organ other than the target organ.
Individual consumer of healthcare services who can be either a patient, resident or tenant
When a medication first begins to work and exerts a therapeutic effect.
A measurement of the amount of drug that produces a therapeutic effect compared to the amount of drug that produces a toxic effect.
The second stage of pharmacokinetics; the process by which medication is distributed throughout the body.
When the maximum concentration of drug is in the body.
The dosing window in which the safest and most effective treatment will occur.
As the dose of a drug increases, the response should increase. The slope of the curve is characteristic of the particular drug-receptor interaction.
The study of how drugs act at target sites of action in the body.
The trough level of medication indicates the lowest concentration of that medication in a person's body. Troughs of medication concentration occur after the drug has been broken down and metabolized by the body.
Medications or other substances that have a physiological effect when introduced to the body.