Prescriptive Authority
Prescriptive authority refers to the legal right granted to advanced practice nurses to
prescribe medication. This authority is determined by state law.
Rational Drug Selection
Rational drug selection is based on an individual patient's needs and considers
disease-specific factors. It serves as a guideline rather than a strict rule.
Drug Selection
The process of selecting a drug involves analyzing several factors, including:
• Cost
• Clinical guidelines
• Availability
• Potential interactions
• Side effects
• Allergies
• Hepatic and renal function
• Need for monitoring
• Special considerations, such as for elderly patients
Basic Components of Medication Education
When educating patients about medication, the key components include:
• Medication name
• Purpose of the medication
• Dosing regimen
• Administration instructions
• Possible adverse effects
• Proper storage requirements
• Associated lab testing
• Potential food and drug interactions
• Duration of therapy
Medication Adherence
Some common barriers to medication adherence include:
• Forgetting to take medication
• Poor planning
• High cost
• Dissatisfaction with the treatment
• Modifying the dosing schedule without guidance
, Pharmacokinetics
Pharmacokinetics refers to how a drug moves through the body.
Key Principles of Pharmacokinetics
• Absorption – How the drug enters the bloodstream
• Distribution – How the drug is transported throughout the body
• Metabolism – How the body processes the drug
• Excretion – How the drug is eliminated from the body
How Drugs Cross Cell Membranes
• Through channels and pores
• Using transport systems (e.g., P-glycoprotein)
• By directly penetrating the membrane
Drug Absorption
Absorption is the process by which a drug moves from the site of administration into
the bloodstream.
Factors Affecting Drug Absorption
• Rate of dissolution – How quickly the drug dissolves
• Surface area – A larger surface area allows faster absorption
• Blood flow – Higher blood flow speeds up absorption
• Lipid solubility – Lipid-soluble drugs cross membranes more easily
• pH partitioning – The effect of pH on drug absorption
Drug Distribution
Distribution refers to how a drug moves from the bloodstream to its target site of
action.
Factors Influencing Drug Distribution
• Blood flow to tissues
• Ability of the drug to exit the vascular system
• Ability of the drug to enter cells
Drug's Ability to Exit the Vascular System
• Through capillary beds (normal process)
• Crossing the blood-brain barrier
• Transferring across the placenta
• Binding to plasma proteins like albumin
Drug's Ability to Enter Cells
• Binds to receptors on the external cell membrane surface