Pharmacologic Principles

1. Pharmacologic Principles Chapter 1, 2, 3

2. 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

3. Drug Names • Chemical • Trade • Patented • Belongs to a company • Generic • Commonly known • Less expensive

4. Phases of Activity • Pharmaceutical • Administered • Dissolves or disintegrates • Pharmacokinetic • Absorbed • Sent to tissues • Metabolized (used) • Excreted (disposed of) • Pharmacodynamic • Ways drug affects the body

5. 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

6. Drug Transport • How does the drug get from point A to point B? • Parenteral Liver Circulation • OR • Gastric Liver Circulation

7. 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

8. 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

9. Chemical Bonds • Agonists • Antagonists • Partial-agonist or Agonist-Antagonist

10. Drug Excretion Organs: liver, kidneys, intestines Kidneys have primary responsibility Breakdown by liver makes kidney’s job easier Some drugs are eliminated through bowels

11. 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

12. 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

13. 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

14. Life Span, con’t. • Adult • Careful of interactions with • Other drugs • Herbal substances • Risk for noncompliance d/t ‘undesirable’ effects

15. 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

16. 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

17. 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?

18. 5 Rights • Basic to medication administration • Right Drug • Right Dose • Right Time • Right Route • Right Patient

19. Errors • IF a med error occurs • 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