General Pharmacology

1. Chapter 16 General Pharmacology

2. Drugs are chemicals used to diagnose, treat, and prevent disease.

3. Medication Forms Used by the EMT-Basic • Compressed powders or tablets (e.g., nitroglycerin) • Liquids for injection (e.g., epinephrine) • Gels (e.g., glucose) • Suspensions (e.g., activated charcoal) • Fine powder for inhalation • Gases (e.g., oxygen) • Aerosol or spray (e.g., nitroglycerin)

4. Names of Drugs • Chemical • States its chemical composition and molecular structure • Generic • Usually suggested by the manufacturer • Official • As listed in the U.S. Pharmacopeia • Brand • The trade or proprietary name

5. Medication Names • Generic • Name listed in the U.S. Pharmacopoeia • Name assigned to drug before it becomes officially listed • Usually a simple form of the chemical name • Trade • Brand name manufacturer uses in marketing the drug

6. Medication Terms • Indications • Most common uses of the drug • Contraindications • Situations in which a drug should not be used • May cause harm to the patient • May have no effect in improving the patient's condition

7. Medication Terms • Dose • How much of the drug should be given • Administration • Route by which the medication is administered • Actions • Desired effects a drug has on the patient/body systems

8. Medication Terms • Side effects • Actions of a drug other than those desired

9. DoseMetric Conversions Kilograms Grams Milligrams Micrograms 1 kg 1000 g 1 g 1000 mg 1 mg 1000 g

10. DoseMetric Conversions Liters Milliliters 1 L 1000 mL 0.5 L 500 mL 0.1 L 100 mL 0.01 L 10 mL 0.001 L 1 mL 1000 mL 1 L

12. Legal • Knowing and obeying the laws and regulations governing medications and their administration is an important part of an EMT’s career. • These include federal, state, and agency regulations.

13. Federal • Pure Food & Drug Act of 1906 • Harrison Narcotic Act of 1914 • Federal Food, Drug, & CosmeticAct of 1938 • Comprehensive Drug AbusePrevention & Control Act of 1970

14. State vs. Local Standards • They vary widely. • Always consult local protocols and with medical direction for guidance in securing and distributing controlledsubstances.

15. New Drug Development

17. Name Generic, trade Classification Mechanism ofAction Indications Pharmacokinetics Side Effects/adverse reactions Routes ofAdministration Contraindications Dosage How Supplied SpecialConsiderations Components of a Drug Profile

18. Providing Patient Care Using Medications • Have current medication referencesavailable. • Take careful drug histories including: • Name, strength, dose of prescribed medications • Over-the-counter drugs • Vitamins • Herbal medications • Allergies

19. Providing Patient Care Using Medications • Evaluate the patient’s compliance, dosage, and adverse reactions. • Consult with medical direction as needed.

20. Seven “Rights” of Medication Administration • Right medication • Right dosage • Right time • Right route • Right patient • Right documentation • Right to refuse

21. De-Mystifying Pharmacology • Drugs do not do anything new. • They can only alter functions that are already occurring in the body. • Replace a function, enhance a function or interrupt a function • Drugs will always leave residual effects. • Even selective-site drugs! • Albuterol and muscle tremors

22. De-mystifying Pharmacology • Drugs usually have to bind to something before anything can occur. • Antacids bind to receptors in the stomach • Morphine binds to euphoria receptors, nausea and vessel control receptors in the brain

23. Pediatric Considerations • Dosages must be administered based on body weight. • Patient may have difficulty with inhalation. • Consider spacer or extension tubing • Patient may be reluctant to take medication. • Enlist patient/parent cooperation

24. Geriatric Considerations • Patient may take several medications. • Prone to adverse effects, drug interactions, inadvertent overdose • When possible, transport all medications to hospital with patient. • May help hospital staff diagnose and manage patient condition

25. Absorption Rates

26. Reassessment Strategies • After drug administration, reassess patient for: • Therapeutic effects • Side effects • Noticeable changes in patient condition • Document time of administration • Document times of ongoing assessments • Vital signs • Changes in patient condition • Therapeutic or side effects

28. Cells talk to each other • Three distinct languages • Nervous system • neurotransmitters • Endocrine system • hormones • Immune system • cytokines

29. In disease, all systems are affected • The three systems can’t exist without each other • The actions of one impact the actions of the others • I.e., stress (nervous system) disrupts endocrine system which may respond with glucocorticoid production = suppressed immune response

30. Drug Classifications • Drugs are classified 3 different ways: • By body system • By the action of the agents • By the drug’s mechanism of action

31. Drug Class Examples • Nitroglycerin • Body system: “Cardiac drug” • Action of the agent: “Anti-anginal” • Mechanism of action: “Vasodilator” • Indications for nitroglycerin • Cardiac chest pain • Pulmonary edema • Hypertensive crisis • Which drug class best describes this drug?

32. Medications Carried on the EMS UnitActivated Charcoal • Used for toxic ingestion • Binds to certain poisons • Prevents absorption • Not all brands are the same. • Some bind much more poison. • Consult medical direction about the brand to use

33. Medications Carried on the EMS UnitOral Glucose • Used for altered mental status, suspected hypoglycemia • Absorbed in the oral mucosa • Provides needed glucose for patient with low blood sugar

34. Medications Carried on the EMS UnitOxygen • Increases oxygen delivery to blood • Essential treatment for hypoxia and hypoperfusion • % of delivered oxygen (dose) determined by flow rates and delivery device

35. Medications carried on the EMS unitEpinephrine • Used to treat severe allergic reaction • Blocks release of histamine • Increases vascular resistance to maintain blood pressure

36. Epinephrine Absorption • What is the concentration and dosing time for subcutaneous and IV epinephrine? • SQ - 1:1000 with repeat doses every 3-5 minutes • Why is there a need for 2 different concentrations? • Epinephrine is a short-lived drug and will break down quickly • SQ absorption is significantly slower than IV • A higher concentration of the drug will assure that enough of the active drug will still be available after it is absorbed

37. Medications carried on the EMS unitAspirin • Action • Produces analgesia • Reduces inflammation and fever by inhibiting the production of prostoglandins • Decreases platelet aggregation

38. Aspirin • For cardiac chest pain • Usual dose • 81 mg x 3 or 4 (243 – 324 mg) po • chewable

39. Men 50 y/o or more (no clinical evidence of coronary disease). ASA - Risk of MI 44% less No significant effect on risk of stroke and no effect on mortality from cardiovascular causes Women 65 y/o or more (no history of cardiovascular disease) ASA - No significant effect on risk of MI or risk of death from cardiovascular causes BUT 24% reduction in risk of ischemic stroke and 17% reduction in stroke risk overall New Info!New England Journal of Medicine, 3/05

41. Drugs carried on the EMS unitActivated Charcoal • To treat poison ingestion • Acts externally to the surface of the bowel to adsorb toxins from the mucosa • Increases drug diffusion rate from plasma into GI tract for absorption

42. Medications EMT-Basic May AssistPrescribed Inhalers • Used to treat bronchoconstriction • Prescribed by patient’s physician • Administration is approved by medical direction and/or by local protocol. • May be carried in the ambulance in some EMS systems

43. Albuterol • Causes bronchodilation by acting on B-2 receptors (B-agonist) • Atrovent (Ipratroprium) • Causes bronchodilation by inhibiting acetylcholine at receptor sites on bronchial smooth muscle

44. Medications EMT-Basic May AssistNitroglycerin • Used to treat ischemic chest pain • Dilates vessels to improve circulation through the coronary arteries • Decreases the workload of the heart by dilating peripheral vessels • Administered under the tongue by tablet or spray

45. Nitroglycerin • How does the drug come packaged? • As a tablet, spray, ointment, liquid (IV) • Nitroglycerin forms and absorption rates • SL: 1-3 minutes • Ointment/transdermal: 30 minutes • IV: immediate!

47. Summary • Medications play a critical role in EMS. • Care must be taken to assess patients to identify the need for medication. • Be familiar with the indications, contraindications, and side effects of administered medications. • Always contact medical direction and/or follow local protocols. • Remember the “rights” of medication administration.