Download Pharmacologic Principles

Pharmacologic Principles
Chapter 1, 2, 3
Understanding
• Nurses must understand both + and –
effects of drugs
• Pharmacotherapeutics
– use of drugs and the clinical indications
for drugs to prevent and treat diseases
• Pharmacodynamics
– study of what the drug does to the body
• Pharmacognosy
– natural drug sources
Drug Names
• Chemical
• Trade
– Patented
– Belongs to a company
• Generic
– Commonly known
– Less expensive
Phases of Activity
• Pharmaceutical
– Administered
– Dissolves or disintegrates
• Pharmacokinetic
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Absorbed
Sent to tissues
Metabolized (used)
Excreted (disposed of)
• Pharmacodynamic
– Ways drug affects the body
First-Pass Effect
• metabolism of a drug by the liver
before its systemic availability
• AKA Bioavailability
• Amount of the drug that makes it into
circulation
Drug Transport
• How does the drug get from point A to
point B?
• Parenteral
Liver
Circulation
• OR
• Gastric
Liver
Circulation
Action Curve
• Time from delivery to start of
therapeutic effect = Onset of Action
• From delivery to maximum therapeutic
effect = Peak Effect
• Total amount of time therapeutic
effect is notable = Duration of Action
Mechanism of Action
• Receptor
– Designated site accepts drug
• Enzyme
– Chemical reaction “glues” drug to site
• Nonspecific
– Drug stimulates changes in cell to allow it
in
Chemical Bonds
• Agonists
• Antagonists
• Partial-agonist or Agonist-Antagonist
Drug Excretion
Organs: liver, kidneys, intestines
Kidneys have primary responsibility
Breakdown by liver makes kidney’s job
easier
Some drugs are eliminated through
bowels
Considerations
• Therapeutic Index – difference
between good & dangerous effects
• Amount of drug circulating =
concentration
• Patient condition – liver & kidney
health, age, GI function
• Tolerance or Dependence
• Interactions
Drug Misadventures
• Adverse Drug Event (ADE)
– Adverse Drug Reaction (ADR)
• Caused by factors inside patient’s body
• Allergy, unknown, kidney or liver disease
• Not able to be controlled
– Medication Error
• Most common type of event
• Related to administration, dispensing,
prescribing
Life Span
• Pediatrics
– Very young have immature livers - can’t
process drugs as well
– Adult drugs may be passed through
breastmilk – check safety if mother is
breastfeeding
– Dosage based on mg/kg for safety
Life Span, con’t.
• Adult
– Careful of interactions with
• Other drugs
• Herbal substances
– Risk for noncompliance d/t ‘undesirable’
effects
Life Span, con’t.
• Elderly
– Be aware of possible diminished:
• liver or kidney function – monitor lab tests
• Cardiac function – be aware of test results
• Digestive changes
– Assess ability to read labels & open
containers
– Assess for potential safety issues – meds
may cause drowsiness or diminished
response
Nursing Process
• Assess
– Patient needs
– Patient & family understanding
– Patient (and family) physical abilities
• Plan (Goal)
– Include patient & family
– Tailor to patient/family needs
– Include social services, prn
Nursing Process, con’t.
• Implement
– Regular re-assessments
– Monitor for changes
– Observe for therapeutic affects
• Evaluate
– Is plan working?
– Does it need modifying?
– What can change?
5 Rights
• Basic to medication administration
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Right Drug
Right Dose
Right Time
Right Route
Right Patient
Errors
• IF a med error occurs
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Admit the error – don’t try to cover it up
Notify physician
Take emergency/first aid measures, prn
Complete proper reporting form
• NEVER record terms “by mistake”, “on
error”, “unintentionally”
• DO NOT record error in patient chart