Topic 8: Pharmacotherapeutics
PHARMACOTHERAPEUTICS
Dr. James Blankenship
DNP, MSN, APRN, FNP-C
LEARNING GOALS FOR THIS PRESENTATION
Safe and effective medication administration
Understand the roles and responsibilities of the Registered Nurse in drug therapy
Apply knowledge from anatomy and physiology to clinical pharmacology
Develop a working understanding of Pharmacokinetics:
ADME: Absorption, Distribution, Metabolism, Excretion
Understand the different types of drug actions/effects:
Therapeutic
Adverse
Toxic
Idiosyncratic
Synergistic
Additive
Antagonistic
Hypersensitivity (allergy vs. anaphylaxis)
Understand the key terms pertaining to drug scheduling and timing
Apply the nursing process to drug therapy
Retrieve and interpret information from a drug reference (electronic or text) and apply it to the clinical setting
ICON LEGEND
Laptops / PowerPoints Down!
OK! Open them back up!
You can cheat… Think as a group, and talk to each other!
You’re on your own! No talking, now you have to use your brain!
KEY TERMS: HANDOUT LOCATED ON MOODLE
Drug: A chemical that affects physiologic processes of a living organism
Pharmacotherapeutics: The branch of pharmacology that deals with the therapeutic uses and effects of drugs
Pharmacodynamics: The study of the effects of drugs and the mechanism of their action
Pharmacokinetics: The study of the absorption, distribution, metabolism, and excretion of drugs (ADME)
Drug Names: Include chemical name, generic name, and trade name
Drug Classification: Grouping of drugs based on similar properties
Contraindication: A specific situation in which a medicine should not be used
Medication Teaching: Patient education regarding medications
Absorption: The process of taking in substances from the environment
Distribution: The dispersion of drugs throughout the fluids and tissues of the body
Metabolism: The chemical alteration of a drug in the body
Excretion: The process of eliminating drugs from the body
Half-Life: The time it takes for the concentration of a drug in the body to be reduced by half
Adverse Effect: An unwanted effect caused by a medication
Enteral: Refers to a route of administration that passes through the digestive tract
Parenteral: Refers to routes that are not enteral; usually injections
FOUR ESSENTIAL KEY TERMS TO START
Drug: Any chemical that affects the physiologic processes of a living organism
Pharmacology: The study or science of drugs
Classification: Drugs are classified according to their chemical structure or therapeutic use
Adverse Effect: Think of this as a side effect; it’s any unwanted effect of a drug, which can be further classified into other effects (such as an allergic reaction)
THE RN’S ROLE IN DRUG THERAPY
Application of the Nursing Process to drug therapy
Ensure that the medication is appropriate for the patient, transcribed correctly, properly administered
Monitor and evaluate the effects of medications
If you administer the drug, you are responsible for it
Providers are responsible for prescribing, and pharmacists dispense medications
Prevention of medication errors is crucial
NINE RIGHTS OF DRUG ADMINISTRATION
These rights are critical to avoid medication errors:
Right drug
Right dose
Right time
Right route
Right patient
Right documentation
Right reason
Right response
Right to Refuse
Following all NINE RIGHTS every time ensures that medication errors are avoided.
TIME-CRITICAL MEDICATIONS
Time-critical medications must be administered within a specific time frame to avoid harm:
Time-critical medications: Must be given 30 minutes before or after the scheduled administration time without causing harm or substandard pharmacological effect.
Non-time critical medications: Can be given between one and two hours early or late without causing harm or substandard pharmacological effects.
HIGH-ALERT MEDICATIONS
Definition: High-alert medications are associated with an increased risk of causing significant harm when they are administered incorrectly.
Examples include:
Insulin
Opiates
Narcotics
Intravenous heparin
Injectable potassium chloride
A strategy to reduce risk is through manual independent double checks with two nurses verifying identical information before administration.
TRANSCRIBING MEDICATION ORDERS
Correct interpretation of orders is vital; verbal orders must always be read back to the provider and documented as “RBVO” (Read Back Verbal Order).
Example of a proper medication order:
Format: MEDICATION / DOSE / ROUTE / FREQUENCY / INDICATION
Example:
Acetaminophen 650 mg PO BID
Acetaminophen 1000 mg PO q6 hours PRN Moderate Pain (4-7)
VALIDATION OF MEDICATION ORDERS
Example:
“Acetaminophen 2 tablets PO TID” is NOT valid (tablet is not a dose).
“Ibuprofen 400 mg q6 hours PRN moderate pain (4-6)” is NOT valid.
“Ibuprofen 600 mg PO q8 hours” is VALID.
PHARMACOKINETICS: OVERVIEW
Definition:
The study of how drugs move through the body, characterized by four key processes:
Absorption: The entry of drug molecules into the bloodstream.
Distribution: The transport of drugs from the absorption site to the action site.
Metabolism: The biochemical alteration of drugs in the body, typically in the liver.
Excretion: The elimination of drugs from the body, primarily through the kidneys.
PHARMACOKINETICS: ABSORPTION
Refers to the passage of drug molecules into the blood after administration.
Factors that can alter absorption include:
Skin permeability
Gastrointestinal peristalsis
Presence of food
TYPES OF ABSORPTION
Enteral Absorption:
Routes include:
Oral
Sublingual
Buccal
Rectal
Parenteral Absorption:
Routes include:
Intravenous (IV)
Intramuscular (IM)
Subcutaneous (Subcut)
Intradermal
Intra-arterial
Intrathecal
Intra-articular
Topical Route:
Considered a parenteral route, as it occurs outside the intestine.
ROUTES OF ADMINISTRATION
Intravenous (IV): Fastest route
Intramuscular (IM): Moderate speed
Subcutaneous (Subcut): Slower than IM
Topical (Top): Varies depending on contact site
Oral (PO): Depends on form (liquid, capsule, tablet)
PHARMACOKINETICS: DISTRIBUTION
Distribution describes how drugs are carried through the bloodstream to their sites of action.
Factors Affecting Drug Distribution:
Amount of protein available in the body
Efficacy of the heart in pumping blood
The body’s fluid levels
Chemical makeup of the drug (solubility)
PHARMACOKINETICS: METABOLISM
Refers to how drugs are chemically changed by the body, usually in the liver.
Drugs may be converted from an active form to an inactive form or vice versa (prodrugs)
Key enzyme involved: Cytochrome P-450
Factors affecting metabolism include:
Liver health
Availability of enzymes
Drug interactions
PHARMACOKINETICS: EXCRETION
Describes how drugs are eliminated from the body, typically via the kidneys.
Other Routes of Excretion:
Biliary excretion (through feces)
Pulmonary (through exhalation)
Sweating
Factors Affecting Excretion:
Kidney health
Fluid intake
ADVERSE EFFECTS AND MONITORING
Examples of using vital signs for drug administration monitoring:
Determining if to administer an ACE inhibitor given BP readings.
Decisions vary based on blood pressure thresholds; knowing acceptable ranges informs the nurse's action.
COMMON CLASSES OF DRUGS
Beta-Blockers
ACE Inhibitors
Factor Xa Inhibitors
Long-Acting Insulins
Anticholinergics
Antihistamines
CONTRAINDICATIONS
Drugs may be contraindicated in certain patient scenarios.
Example: Patients with low blood pressure should not receive antihypertensive medications like ACE inhibitors due to the risk of further lowering blood pressure.
ADVERSE EFFECTS
Categories:
Minor: Minor reactions needing monitoring (e.g., slight itching)
Severe: Require immediate action (e.g., severe allergic reactions, very low blood pressure)
MULTIPLE DRUGS AND INTERACTIONS
Additive Effects: 1+1 = 2
Antagonistic Effects: 1-1 = 0
Synergistic Effects: 1+1 = 3
Importance of medication reconciliation: knowing all medications including OTC, herbs, and supplements.
TIMING OF DRUG ADMINISTRATION
Key Terms:
Onset of Action: When a drug begins to take effect
Peak: Maximum concentration of the drug in the body
Trough: Minimum concentration before the next dose
Steady State: When drug absorption equals elimination
Half-Life: Time required for the concentration of the drug to reduce by half; about 3-5 half-lives to reach steady state.
Loading Dose: Initial large dose to reach steady state faster
THERAPEUTIC INDEX
Definition: Refers to the range between effective and toxic concentrations of a drug.
Narrow Therapeutic Index: Requires tight control (e.g., Vancomycin)
Wide Therapeutic Index: More flexibility in administration (e.g., Ibuprofen)
ETHICAL CONSIDERATIONS
Non-compliance: Can be intentional or unintentional
Patient Autonomy: Patients have the right to refuse medications.
Placebos: Must be disclosed in research settings only; never assume patient ignorance of their treatment.
OTHER CONSIDERATIONS
Gender differences in medication response
Age-related physiological changes affecting drug metabolism
Patient’s healthcare access and comorbidities that may affect drug therapy
DRUG REFERENCES
Drug references can be print or electronic; must be current (<5 years)
Examples include UpToDate and Epocrates as reputable electronic references
ESSENTIAL INFORMATION TO RECORD
Name and Class of the Drug
Indications
Usual Routes and Dosages
Administration Methods
Adverse Effects and Contraindications
Nursing Considerations
PRACTICAL APPLICATION
Essential to document every medication the patient is on and include patient education on potential interactions or contraindications.
DID YOU KNOW?
Nurses are responsible for more than just medication administration; they monitor, document, and adapt therapies as needed based on patient response.