NURS 615 EXAM 1 STUDY GUIDE:
PHARMACOLOGY AND PRESCRIBING
Clinical Judgment in Prescribing Medications
Factors Influencing Clinical Judgment
• Clinical judgment in prescribing medications is influenced by patient-specific factors such
as age, weight, and comorbidities.
• The prescriber's knowledge and experience play a crucial role in determining the
appropriateness of a medication.
• Consideration of drug interactions and potential adverse effects is essential for safe
prescribing.
• Awareness of the latest clinical guidelines and evidence-based practices is vital for
effective decision-making.
• Socioeconomic factors, including cost and access to medications, can impact prescribing
choices.
• Continuous education and staying updated with pharmacological advancements are
necessary for optimal patient care.
Criteria for Choosing Effective Drugs
• Efficacy: The drug must demonstrate a significant therapeutic effect in clinical trials.
• Safety: The risk of adverse effects should be minimal compared to the benefits of the
drug.
• Cost-effectiveness: The drug should be affordable for the patient and healthcare system.
• Patient compliance: The drug regimen should be easy for the patient to follow,
considering dosing frequency and route of administration.
• Availability: The drug should be readily accessible in the market.
• Specificity: The drug should target the intended condition without affecting other
systems unnecessarily.
Pharmacokinetics and Pharmacodynamics
, Passive Diffusion and Drug Absorption
• Passive diffusion is the primary mechanism by which most drugs are absorbed across cell
membranes, driven by concentration gradients.
• Factors affecting passive diffusion include lipid solubility, molecular size, and ionization
state of the drug.
• The pH of the environment can influence the ionization of weak acids and bases,
affecting their absorption.
• Formulation of the drug (e.g., tablet, liquid) and route of administration (e.g., oral,
intravenous) also impact absorption rates.
• First-pass metabolism can significantly reduce the bioavailability of orally administered
drugs before they reach systemic circulation.
• Understanding these factors is crucial for optimizing drug delivery and therapeutic
outcomes.
Drug Metabolism and Cytochrome P450 System
• Drug metabolism primarily occurs in the liver, where enzymes convert lipophilic
compounds into more hydrophilic metabolites for excretion.
• The cytochrome P450 (CYP450) enzyme system plays a critical role in drug metabolism,
with various isoenzymes responsible for metabolizing different drugs.
• Factors influencing drug metabolism include genetic polymorphisms, age, liver function,
and concurrent medications.
• Phase I reactions involve oxidation, reduction, or hydrolysis, while Phase II reactions
involve conjugation to enhance water solubility.
• Understanding the role of CYP450 enzymes is essential for predicting drug interactions
and individualizing therapy.
• Drug metabolites can have different pharmacological effects compared to the parent
compound, impacting therapeutic outcomes.
Adverse Drug Reactions and Drug Interactions
Types of Adverse Drug Reactions (ADRs)
• ADRs can be classified into four types of hypersensitivity responses: Type I (IgE-
mediated), Type II (cytotoxic), Type III (immune complex), and Type IV (delayed-type).
PHARMACOLOGY AND PRESCRIBING
Clinical Judgment in Prescribing Medications
Factors Influencing Clinical Judgment
• Clinical judgment in prescribing medications is influenced by patient-specific factors such
as age, weight, and comorbidities.
• The prescriber's knowledge and experience play a crucial role in determining the
appropriateness of a medication.
• Consideration of drug interactions and potential adverse effects is essential for safe
prescribing.
• Awareness of the latest clinical guidelines and evidence-based practices is vital for
effective decision-making.
• Socioeconomic factors, including cost and access to medications, can impact prescribing
choices.
• Continuous education and staying updated with pharmacological advancements are
necessary for optimal patient care.
Criteria for Choosing Effective Drugs
• Efficacy: The drug must demonstrate a significant therapeutic effect in clinical trials.
• Safety: The risk of adverse effects should be minimal compared to the benefits of the
drug.
• Cost-effectiveness: The drug should be affordable for the patient and healthcare system.
• Patient compliance: The drug regimen should be easy for the patient to follow,
considering dosing frequency and route of administration.
• Availability: The drug should be readily accessible in the market.
• Specificity: The drug should target the intended condition without affecting other
systems unnecessarily.
Pharmacokinetics and Pharmacodynamics
, Passive Diffusion and Drug Absorption
• Passive diffusion is the primary mechanism by which most drugs are absorbed across cell
membranes, driven by concentration gradients.
• Factors affecting passive diffusion include lipid solubility, molecular size, and ionization
state of the drug.
• The pH of the environment can influence the ionization of weak acids and bases,
affecting their absorption.
• Formulation of the drug (e.g., tablet, liquid) and route of administration (e.g., oral,
intravenous) also impact absorption rates.
• First-pass metabolism can significantly reduce the bioavailability of orally administered
drugs before they reach systemic circulation.
• Understanding these factors is crucial for optimizing drug delivery and therapeutic
outcomes.
Drug Metabolism and Cytochrome P450 System
• Drug metabolism primarily occurs in the liver, where enzymes convert lipophilic
compounds into more hydrophilic metabolites for excretion.
• The cytochrome P450 (CYP450) enzyme system plays a critical role in drug metabolism,
with various isoenzymes responsible for metabolizing different drugs.
• Factors influencing drug metabolism include genetic polymorphisms, age, liver function,
and concurrent medications.
• Phase I reactions involve oxidation, reduction, or hydrolysis, while Phase II reactions
involve conjugation to enhance water solubility.
• Understanding the role of CYP450 enzymes is essential for predicting drug interactions
and individualizing therapy.
• Drug metabolites can have different pharmacological effects compared to the parent
compound, impacting therapeutic outcomes.
Adverse Drug Reactions and Drug Interactions
Types of Adverse Drug Reactions (ADRs)
• ADRs can be classified into four types of hypersensitivity responses: Type I (IgE-
mediated), Type II (cytotoxic), Type III (immune complex), and Type IV (delayed-type).
