1 2005 EMT-Intermediate Curriculum Bridge Course Pharmacology and Pharmacology and Medication Administration Medication Administration 2005 EMT-Intermediate Curriculum Bridge Course Goals for the class Goals for the class • Build a broad foundation of knowledge regarding the characteristics and actions of medications – How the body responds to medications – Major organs and systems impacted by most prehospital medications • Apply the concepts of pharmacology to the development of better skill in patient assessment and management 2005 EMT-Intermediate Curriculum Bridge Course Objectives Objectives • Discuss how drugs are classified. (1) • Explain the special considerations in drug treatment with regard to pregnant, pediatric and geriatric patients. (4) • Discuss the EMT-I’s responsibilities and scope of management pertinent to the administration of medications. 2005 EMT-Intermediate Curriculum Bridge Course Objectives Objectives • Describe the mechanisms of drug action… (9) • Defend medication administration by an EMT-I to effect positive therapeutic effect. 2005 EMT-Intermediate Curriculum Bridge Course De De- Mystifying Pharmacology 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 2005 EMT-Intermediate Curriculum Bridge Course De De- mystifying Pharmacology 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
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2005 EMT-Intermediate Curriculum Bridge Course
Pharmacology and Pharmacology and Medication AdministrationMedication Administration
2005 EMT-Intermediate Curriculum Bridge Course
Goals for the classGoals for the class
• Build a broad foundation of knowledge regarding the characteristics and actions of medications– How the body responds to medications– Major organs and systems impacted by most
prehospital medications• Apply the concepts of pharmacology to the
development of better skill in patient assessment and management
2005 EMT-Intermediate Curriculum Bridge Course
ObjectivesObjectives
• Discuss how drugs are classified. (1)• Explain the special considerations in
drug treatment with regard to pregnant, pediatric and geriatric patients. (4)
• Discuss the EMT-I’s responsibilities and scope of management pertinent to the administration of medications.
2005 EMT-Intermediate Curriculum Bridge Course
ObjectivesObjectives
• Describe the mechanisms of drug action… (9)
• Defend medication administration by an EMT-I to effect positive therapeutic effect.
• Understand how drugs in your scope of practice work in the body– How they alter body functions– Binding sites of drug classes and expected actions– Residual effects of specific drug classes
• Keep your knowledge base current!– New drugs are approved for use every day– www.Rxlist.com
• Top 200 prescriptions per year
2005 EMT-Intermediate Curriculum Bridge Course
EMTEMT--I ResponsibilitiesI Responsibilities
• Use drug reference literature to assist with your understanding– Indications, contraindications, precautions– PDR, online resources, nursing drug
guides, field guides• Seek out information from other
professionals– Supervising physician, pharmacists, etc.
2005 EMT-Intermediate Curriculum Bridge Course
EMTEMT--I I Responsibilites Responsibilites in in Patient CarePatient Care
• Perform a comprehensive drug history– Prescribed medications– Over-the-counter medications– Vitamins or herbal supplements– Recreational/illicit substances and alcohol– Drug interactions/reactions
2005 EMT-Intermediate Curriculum Bridge Course
Impacts on the EMTImpacts on the EMT--I with I with Patient CarePatient Care
• Drug administration– Use the correct precautions and
administration rates– Observe for expected and unexpected
effects of the drug– Document patient responses from the drug
• Good and bad!• Pertinent vital signs
• Use the Rights of Drug Administration2005 EMT-Intermediate Curriculum
Bridge Course
The Rights of Drug The Rights of Drug AdminstrationAdminstration
• Right patient• Right drug• Right dose• Right route
• Right time• Right documentation• Right to refuse
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2005 EMT-Intermediate Curriculum Bridge Course
The The ““6 Rights6 Rights”” In Action?In Action?Four days after an alert conscious patient was admitted to the hospital, he died after receiving the wrong medication.
A pharmacist ordered Librium (a sedative) instead of Lithium, a drug used to manage bipolar disease. The dose for lithium was 300mg. The patient instead received 300mg of the Librium, which was 60 times the safe dose for the medication. Other sedatives, antidepressants and antibiotics were administered concurrently as part of his care plan.
For two days the patient’s blood pressure continued to drop until he became lethargic and unresponsive.
A hospital spokesman stated that the autopsy report concluded that the patient died from pneumonia.
2005 EMT-Intermediate Curriculum Bridge Course
The Basics of Drug ClassesThe Basics of Drug Classes
2005 EMT-Intermediate Curriculum Bridge Course
Drug ClassificationsDrug Classifications
• Drugs are classified 3 different ways:– By body system– By the action of the agents– By the drug’s mechanism of action
2005 EMT-Intermediate Curriculum Bridge Course
Drug Class ExamplesDrug Class Examples• Nitroglycerin
– Body system: “Cardiac drug”– Action of the agent: “Anti-anginal”– Mechanism of action: “Vasodilator”
Increase in HR, conductivityIncrease in contractions
Beta-2Dilation of bronchioles
Skeletal muscle tremorsInhibition of uterine contractions
Receptor Sites
Neurotransmitters:Norepinephrine
Epinephrine
Sympathetic
Neurotransmitter:Acetylcholine (ACh)
Parasympathetic
Autonomic Nervous System
Drug Classification Names:
• “Sympathomimetics”
• “Adrenergics”
• “Beta-2 Agonist”
• “Non-Specific Beta Agonist”
• “Beta Blocker”
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2005 EMT-Intermediate Curriculum Bridge Course
The Parasympathetic NSThe Parasympathetic NS
• What organs will help out the typical couch potato?– Digestion– Slow heart rate– Smaller bronchioles – Pupil size
• Normal or constricted
• This system works best at rest
Couch Potato
2005 EMT-Intermediate Curriculum Bridge Course
OverOver--stimulation of the stimulation of the Parasympathetic NSParasympathetic NS
• A little is a good thing, but too much stimulation of this system leads to trouble– Very slow heart rates– Bronchoconstriction– Major gastrointestional actions
• Vomiting• Diarrhea
2005 EMT-Intermediate Curriculum Bridge Course
Receptor Sites:Alpha 1 and 2Beta 1 and 2
Neurotransmitters:Norepinephrine
Epinephrine
Sympathetic
Heart:Decrease in HR and conduction
Lungs:Bronchoconstriction
Increase in mucus production
GI Tract:"SLUDGE"
Increase in motilityVomiting
Effects
Neurotransmitter:Acetylcholine (ACh)
Parasympathetic
Autonomic Nervous System
Drug Classification Names
• “Parasympatholytics”
• “Anticholinergics”
• “Cholinergics”
2005 EMT-Intermediate Curriculum Bridge Course
Autonomic Nervous System Autonomic Nervous System Sympathetic Receptor Site Sympathetic Receptor Site
ActionAction
2005 EMT-Intermediate Curriculum Bridge Course
1) Brain sends out the response via nerve paths2) Nerve moves the response: depolarization3) Depolarization stimulates norepinephrine sacks
• Sacks move to the end of the nerve and dump out their contents
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2005 EMT-Intermediate Curriculum Bridge Course
4) Norepinephrine travels across the synapse• Attaches to a receptor on the organ, organ
responds to the signal5) Norepineprhine detaches and is deactivated
• 2 options: destroy it or move it back into its sack
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2005 EMT-Intermediate Curriculum Bridge Course
Nervous System ReviewNervous System Review
• You are to give a dose of a parasympatholytic. What is it expected to do?– Bronchodilation– Increase GI motility– Stimulate vomiting– Increase HR
• Is a parasympatholytic the same as a sympathomimetic?
2005 EMT-Intermediate Curriculum Bridge Course
Nervous System ReviewNervous System Review
5 minutes after you gave a non-specific beta agonist, you notice that the patient is complaining of palpitations.
This effect is considered to be:a) A desired effect of the drugb) An expected side effect of the drugc) An unpredictable, adverse effect of the
drug
2005 EMT-Intermediate Curriculum Bridge Course
Nervous System ReviewNervous System Review
• What other side effects or adverse reactions would you expect to see in a patient after giving them an adrenergic drug?– Muscle tremors– Tachycardia– Elevated BP– Chest discomfort
2005 EMT-Intermediate Curriculum Bridge Course
Nervous System ReviewNervous System Review
• A patient is taking atenolol, a Beta-1 specific blocker. What is the expected effects of this drug?– Lowered HR– Decrease in contraction and conduction
• What would be an expected side effect of the drug?– Dizziness when standing
2005 EMT-Intermediate Curriculum Bridge Course
EMTEMT--I Nervous System DrugsI Nervous System Drugs• Epinephrine 1:1,000
Drug Mechanisms Drug Mechanisms of Actionof Action
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2005 EMT-Intermediate Curriculum Bridge Course
Phases of Drug ActivityPhases of Drug Activity
• Pharmaceutical– Disintegration and dissolution
• Pharmacokinetic– How the drug gets in, how it reaches the
target and how it gets out of the body• Pharmacodynamic
– The response of the tissue to the drug
2005 EMT-Intermediate Curriculum Bridge Course
Pharmaceutical PhasePharmaceutical Phase
• Disintegration– Breakdown of the solid form of the
medication• Dissolution
– Drug goes into solution form and is able to be absorbed
– The more rapid this step, the faster the drug will be absorbed
2005 EMT-Intermediate Curriculum Bridge Course
PharmacokineticsPharmacokinetics
• Absorption• Distribution• Metabolism• Excretion
2005 EMT-Intermediate Curriculum Bridge Course
AbsorptionAbsorption
Drug Factors That Drug Factors That Impact AbsorptionImpact Absorption
• Fast, efficient absorption is achieved with the following:– High surface area of the tissue– Rich blood supply at the tissue– Thin membranes between the tissue and the
bloodstream• Drug solubility
– Lipid soluble drugs absorb faster in tissues and cells than water soluble drugs
2005 EMT-Intermediate Curriculum Bridge Course
Other Drug Factors That Other Drug Factors That Impact AbsorptionImpact Absorption
• Drug concentration– High concentrations of the drug at the
tissue will achieve better absorption as well• pH of the drug
– Glucagon does not absorb into cells readily• Requires very low or very high pH to break it
• Drugs are studied for the following:– Plasma levels
• How fast they reach active levels
– Biologic half-life• How long it takes to break down half of the drug
– Minimum effective concentration• How much of the drug it takes to create a response
– Therapeutic threshold• How much of the drug is too much, or toxic
2005 EMT-Intermediate Curriculum Bridge Course
Minimum Effective Concentration
Therapeutic Threshold
Plasma Levels
DrugDrug--Response:Response:LidocaineLidocaine
• Graph: single bolus of lidocaine• Relatively rapid breakdown of the drug to sub-
therapeutic levels– Half-life is 7-30 minutes
• Dosing regimen is every 3-5 minutes in order to keep the drug at or near therapeutic levels
2005 EMT-Intermediate Curriculum Bridge Course
LidocaineLidocaine
Top Graph• Multiple boluses
create varied therapeutic levels– Blue lineLower Graph
• Bolus with a drip:– Smaller constant
level of infusion will provide just enough lidocaine to replace elements of the bolus that was broken down
2005 EMT-Intermediate Curriculum Bridge Course
DrugDrug--Response:Response:LidocaineLidocaine
• Lidocaine is broken down by the liver• What will happen if the same dosing regimen for the
drug is used in patients with liver failure?– Takes longer to break down the drug (increase in its half life)– Toxic levels can occur in lidocaine’s target organs
• Heart – asystole• Brain – altered levels of consciousness
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2005 EMT-Intermediate Curriculum Bridge Course
Drug Interaction VariablesDrug Interaction Variables
• Intestinal absorption• Competition for plasma
protein binding• Drug metabolism
– “Biotransformation”
• Action at the receptor site
• Renal excretion• Alteration of electrolyte
balance
• Drug-drug interactions
• Other drug interactions– Alcohol consumption– Cigarette smoking
2005 EMT-Intermediate Curriculum Bridge Course
Pharmacology Case StudyPharmacology Case Study
2005 EMT-Intermediate Curriculum Bridge Course
Case StudyCase Study
You respond to “Jan,” a 45 year-old female who was stung by a bee while at a family picnic. She is lying in the grass field. She is conscious but shaking. She has hives on her arms, chest and legs.
A family member tells you that they administered her Epi-Pen 5 minutes ago.
She is conscious. Her vital signs include a respiratory rate of 24, heart rate of 110 and a blood pressure of 156/70.
2005 EMT-Intermediate Curriculum Bridge Course
More Patient Information
Jan has a history of “severe” reactions to bee stings. Her lips appear swollen but her family members state that “her whole face was swollen before we gave her the Epi-Pen.”
Her lung sounds are clear.
2005 EMT-Intermediate Curriculum Bridge Course
Embellishment!
• Would you expect a change in Jan’s response to epinephrine if she…– Was 5 years old?– Was 20 and pregnant?– Was 65 (and not pregnant)?
– Was old, pregnant, and acted like she was 5? Just Kidding!!
2005 EMT-Intermediate Curriculum Bridge Course
A New EMTA New EMT--I Treatment I Treatment Option for AnaphylaxisOption for Anaphylaxis
• Benadryl– Class: “Antihistamine”– Antagonist to histamine
• Competes for the same receptor sites as histamine
• Does not directly control the release of histamine
• Effectiveness is dependent on concentration– Higher levels of histamine will be more likely
to bind to the receptor than Benadryl
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2005 EMT-Intermediate Curriculum Bridge Course
Benadryl v. EpinephrineBenadryl v. Epinephrine
• When should you give one medication over the other? Why?– Benadryl not as effective with massive
histamine release– Epinephrine binds to other cell receptors in
critical areas• Beta receptors• More potent response and will override the
histamine response
2005 EMT-Intermediate Curriculum Bridge Course
Benadryl ActionsBenadryl Actions• Half-life
– 2.5 - 7 hours
• Drug effects– Rapid onset with wide
distribution– Extensively broken down
by the liver– Excreted extensively by
the kidneys– Also has anticholinergic
activity
• How will this drug act differently in children?
• How will it impact the elderly?
• With which medical conditions will it cause more trouble?
Drugs in KidsDrugs in Kids
• Less than one year– Lower levels of plasma protein
• Increased likelihood for drugs to be in a free-form state
– More potent effects of the drug– Kidneys and liver are less developed
• Potentially slower activation and elimination of drugs
2005 EMT-Intermediate Curriculum Bridge Course
Kids and DrugsKids and Drugs• Over 1 year
– Liver enzymes more active than an adult– Faster work in the kidneys than an adult
• Later childhood causes a faster elimination of drugs
– Dosing for drugs are based on the child’s weight• More proportional response
Pregnancy Pregnancy ConsiderationsConsiderations
• 1st trimester– Lipid soluble drugs can cross into the placenta– Immature fetal liver and kidneys may store drugs longer
• Later pregnancy– Higher HR, CO = faster absorption and onset of drugs– Increased fatty tissue may cause more storage of lipid-soluble
drugs– Drug dependency by the fetus if the mother is addicted to opiate
drugs• During labor
– May depress respirations in the neonate
The ElderlyThe Elderly
• Decreased cardiac output and metabolism– Longer drug effects (pain medications)– Less filtration through the kidneys – keeps
drugs in circulation longer• More body fat and less total body water
– Stores more fat-soluble drugs– Higher concentration of drugs in the body
• Decreased plasma proteins– More drugs circulating in their free-form state
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2005 EMT-Intermediate Curriculum Bridge Course
The half-life of Valium in a 20 year-old lasts approximately 20
hours.
For a person in their 80s, this half-life extends to 90 hours!