Pharmacology for Paramedics

1. Pharmacology for Paramedics Jeremy Maddux, NREMTP, I/C

2. Historical TrendsIn Pharmacology • Ancient health care • Herbs & minerals used to treat sick & injured • Documented use as long as 2,000 B.C. • Ancient Egyptians, Arabs, & Greeks • The renaissance period • Pharmacology became a distinct and growing discipline • Separate from medicine

3. Historical TrendsIn Pharmacology • Modern health care • Last 50 years have seen explosion in growth of biological sciences and associated medicine and pharmacology • The present period of change • Research directed to discover new treatments, cures and prevention of disease • New trends in health care and pharmaceutics • Orphan drugs developed to treat rare and chronic diseases

4. Drug Names • Chemical Name • Precise description of the drug’s chemical composition and molecular structure • 7-chloro-1, 3-dihydro-1methyl-5-phenyl-2H-1, 4-benzodiazepin-2-one • Generic Name (Non-proprietary Name) • Official name approved by the FDA • Usually suggested by the first manufacturer • diazepam

5. Drug Names • Official Name • The name assigned by the USP • diazepam, USP • Trade Name (Proprietary Name) • The brand name registered to a specific manufacturer or owner • Valium ®

6. Sources of Medications • Plants • morphine sulfate, atropine • Animals and/or Humans • insulin, ACTH • Minerals • sodium bicarb, calcium • Synthetic (Chemical Substances) • lidocaine, diazepam

7. Drug Classification • By Body System • Sympathetic Agonist, Anticholinergic • Class of Agent • Antidysrhythmic, Analgesic • Mechanism of Action • Calcium Channel Blocker, Diuretic

8. Sources of Drug Information • Physicians Desk Reference (PDR) • Hospital Formulary (HF) • Drug Inserts • Other texts/sources • Brady • Internet • Mosby

9. Medication Regulation & Licensing • Pure Food & Drug Act (1906) • Improve quality of labeling • Harrison Narcotic Act (1914) • Regulated importation, manufacture, sale, & use of opium and cocaine • Federal Food, Drug, & Cosmetic Act (1938) • Empowered the FDA (standards)

10. Medication Regulation & Licensing • Durham-Humphrey Amendments (1951) • Required prescriptions • New category (over-the-counter) • Controlled Substances Act (1970) • Replaced the Harrison Narcotic Act • Created 5 Drug Schedules

11. Schedule I Heroin, LSD NO accepted medical use Schedule II Opium, Cocaine Accepted medical use Severe dependence Schedule III Tylenol with Codeine Low dependence Schedule IV Diazepam Limited dependence Schedule V Opiods (cough) Drug Schedules

12. Scope of Management • You are held responsible for safe and therapeutically effective drug administration • Personally responsible for each drug you administer • Legally • Morally • Ethically

13. Use correct precautions and techniques Observe and document effects of drugs Keep knowledge base current Establish & maintain professional relationships Understand pharmacology Identify drug indications and contraindications Seek drug reference literature Take a drug history from patients Consult with medical direction Scope of Management

14. The “Six Rights” of Medication Administration • Right Medication • Right Dose • Right Time • Right Route • Right Patient • Right Documentation

15. Autonomic Pharmacology • Central Nervous System (CNS) • Peripheral Nervous System • Somatic Nervous System • Autonomic Nervous System (ANS) • Sympathetic Branch • Parasympathetic Branch

17. Autonomic Nervous System Characteristics “Feed or Breed” “Fight or Flight”

18. ANS Anatomy & Physiology • The nerves of the ANS exit the CNS and subsequently enter specialized structures called “autonomic ganglia” • Preganglionic fibers • Pass between the central nervous system and the ganglia • Postganglionic fibers • Pass between the ganglia and the effector organ

19. Sympathetic versusParasympathetic • Sympathetic ganglia • Located close to the spinal cord or midway between the spinal cord and the effector organ • Parasympathetic ganglia • Located close to or within the walls of the target organs

21. Cholinergic and Adrenergic Fibers • Cholinergic • Fibers that release acetylcholine • All preganglionic and postganglionic of the parasympathetic division • Adrenergic • Fibers that release norepinephrine • Most postganglionic fibers of the sympathetic division are adrenergic, but some are cholinergic

22. Neurochemical Transmission • No actual physical connection exists between two nerve cells or between a nerve cell and the organ it innervates • Syanpse • Space between nerve cells • Neruroeffector junction • Specialized synapse between two nerve cells or a nerve cell and an organ • Neurotransmitter • Chemical messenger that conducts a nervous impulse across a synapse

24. Neurotransmission

25. Neurotransmitters • Acetylcholine • Preganglionic nerves of sympathetic nervous system • Preganglionic and postganglionic nerves of the parasympathetic nervous system • Norepinephrine • Postganglionic nerves of the sympathetic nervous system

26. Acetylcholine • For cholinergic synapses acetylcholine molecules combine with cholinergic receptor molecules • Nicotinic Receptors • Produces an excitatory response • Muscarinic Receptors • Produce an excitatory or inhibition, depending on where the target receptors are found

28. Norepinephrine • For adrenergic synapses norepinephrine molecules combine with adrenergic receptor molecules • Alpha Receptors • Blood vessels • Beta Receptors • Heart • Lungs

29. Catecholamines &Related Substances • Dopamine • Raises pain threshold & increases tolerances to pain • Epinephrine • Emergency hormone releases by the adrenal medulla

30. Catecholamines &Related Substances • Norepinephrine • Important transmitter of nerve impulses • Serotonin • Released by injured tissues • Enhances pain at local level • Inhibits pain when it acts on the CNS

31. Brain Peptides • Enkephalin • Weak analgesic effect that binds with opiate receptors • Endorphin • Higher analgesic effect that’s highly concentrated in the hypothalamus and spinal cord • Dynorphin • Analgesic effects fifty times than others

32. General Properties of Drugs • Drugs do not confer any new functions on a tissue or organ, they only modify existing functions • Drugs in general exert multiple effects rather than a single effect • Drug action results from a physiochemical interaction between the drug and a functionally important molecule in the body

33. Pharmokinetics • Mechanisms that affect pharmokinetics • Absorption • Distribution • Biotransformation • Excretion

34. Variables Route of Administration Solubility of the Drug (H2O) Drug Concentration (ionize) pH Mechanisms Diffusion Osmosis Filtration Absorption

35. Distribution • Drug reservoirs • Plasma protein binding (molecules) • Tissue binding (adipose or fat) • Barriers • Blood-brain barrier • Placental barrier

36. Biotransformation • Also known as metabolism where a drug is chemically converted to a metabolite • Active metabolites • Inactive metabolites

37. Excretion • Organs of excretion • Kidneys • Intestine • Lungs • Sweat & salivary glands • Mammary glands

39. Liquid Solutions Tinctures Suspensions Spirits Emulsions Elixirs Syrups Solid Pills Powders Tablets Suppositories Capsules Gas Drug Forms

40. Routes ofDrug Administration • Effects the rate at which the onset of action occurs and may effect the therapeutic response that results • Route is crucial in determining the suitability of a drug • First pass metabolism • Drugs are given for either their local or systemic effects

41. Buccal Oral (PO) Orogastric Nasogastric Rectal (PR) Sublingual (SL) Enteral Routes

42. Endotracheal Inhalation (Neb) Instillation Intradermal Intramuscular (IM) Intraosseous (IO) Intravenous (IV) Nasal Subcutaneous (SQ) Transdermal Umbilical Parenteral Routes

43. Mechanics ofDrug Action • To produce optimal effect or therapeutic effects, a drug must reach appropriate concentrations at its site of action • Molecules of the chemical compound must proceed from point of entry into the body to the tissues with which they react • The magnitude of the response depends on the dosage and the time course of the drug in the body

44. Pharmaceutical Disintegration of dosage form Dissolution of drug Pharmocokinetic Absorption Distribution Metabolism Excretion Pharmacodynamic Drug-receptor interaction Mechanics ofDrug Action Concentration of the drug at its site of action is influenced by various processes

45. Pharmaceutical Effects • Disintegration of dosage form • Solid or liquid form • Enteric coated • Dissolution of drugs • Rate at which a solid drug goes into a solution after ingestion • The faster the rate of dissolution, the more quickly the drug is absorbed

46. Pharmacodynamics • The study of how a drug acts on a living organism, including the pharmacological response observed relative to the concentration of the drug at an active site in the organism

47. Drug Receptor Interaction • Affinity • Drug’s propensity to bind or attach itself to a given receptor site • Efficacy (intrinsic activity) • Drug’s ability to initiate biological activity as a result of binding to a receptor site

48. Drug Receptor Interaction • Agonists • Drug that binds to a receptor site and causes a physiological response • Antagonists • Drug that binds to a receptor site and prevents a physiological response or prevents another drug from binding to a receptor site

49. Type of Receptors • Beta 1 • Beta 2 • Alpha 1 • Alpha 2 • Dopaminergic

50. Alpha Receptors • Alpha 1 Receptors • Postsynaptic receptors located on effector organs • Stimulate contraction of smooth muscle • Results in increase in BP • Alpha 2 Receptors • Found on presynaptic & postsynaptic nerve endings • Inhibit further release of norepinephrine • Mediate vasoconstriction