© 2006 The McGraw Hill Companies
Pharmacology
© 2006 The McGraw Hill Companies
Introduction
Introduction
• Drugs are chemical agents used in the diagnosis, treatment, and prevention of disease
What is pharmacology?
Why is it important?
Introduction
• Written records of drug use date back to the ancient Egyptians
• Hippocrates wrote extensively about drugs
• During his time, a more scientific approach was used in treating specific diseases with drugs
Introduction
• Subspecialties of Pharmacology
–Pharmacokinetics
–Pharmacodynamics
–Pharmacogenetics
–Pharmacogenomics
Introduction
• Pharmacokinetics is dependent upon the body’s ability to move substances within the body– Active transport– Facilitated diffusion– Passive transport
Pharmacology Basics
• Pharmacokinetics considerations– Molecule size and shape– Solubility in water and lipids– Ability to bind to tissue proteins– Ionization
Solubility Exercise
Introduction
• Pharmacodynamics – Study of the
mechanisms by which specific drug dosages act to produce biochemical or physiological changes
Introduction
• Pharmacodynamics – Drugs may act in four different ways:
• Bind to a receptor site• Change the physical properties of the cell• Chemically combine with other chemicals• Alter a normal metabolic pathway
Introduction
• Pharmacogenetics and pharmacogenomics– Study unique genetic processes linked to
DNA coding and genetics
Pharmacogenosy
• The study of natural drug sources– Plants– Animals– Minerals
• What are some common examples of each drug source?
Pharmacogenosy
– Researchers can now manipulate the molecular structure of substances to create synthetic drugs
Plant Sources of Drugs
• Oldest source of medications
• Drugs may consist of using the entire plant, leaves, roots, bulbs, stems, seeds, buds, or blossoms
Animal Sources of Drugs
• Body fluids or glands from animals can act as sources for drugs
• Hormones• Oils and fats• Enzymes
Mineral Sources of Drugs
• Metallic and nonmetallic minerals provide various inorganic materials
• Occur naturally or are combined to form acids, bases, or salts
Introduction
• Laboratory-produced drug sources – New drugs may be a
more pure form of a naturally occurring drug or they may be a synthetic form
Routes
• Routes of Administration– Enteral Route– Parenteral Route– Topical Route
Introduction
• Subroutes of administration– Ingestion– Injection– Absorption– Inhalation
Route of Administration
• Depends of many factors– Accessibility– Rate of absorption– Deactivation by enzymes or acids– Toxicity to tissues
Drug Absorption
• Drug’s progress from its pharmaceutical dosage form to a biologically available substance
• Several factors affect drug absorption
Factors
1. Solubility
2. Concentration
3. pH
4. Site of absorption
5. Blood supply
6. Bioavailability
RouteOral (PO)
Subcutaneous (SQ)
Topical
Intramuscular (IM)
Rectal (PR)
Sublingual (SL)
Endotracheal (ET)
Inhalation
Intraosseous (IO)
Intavenous (IV)
Rate of AbsorptionSlow
Slow
Moderate
Moderate
Rapid
Rapid
Rapid
Rapid
Immediate
Immediate
Drug Forms
• Usually consist of a powder dissolved in a liquid– Solute: drug– Solvent: liquid in which it is dissolved
• Primary difference between one preparation and another is the solvent
• What is a solution?
Drug Forms
• Liquids
• Solids
• Suppositories
• Inhalants
• Sprays
• Creams/lotions
• Patches
• Lozenges
Liquid Drugs
– Solutions
– Tinctures
– Suspensions
– Spirits
Liquid Drugs
–Emulsions
–Elixirs
–Syrups
Routes of Administration
–Enteral• Orally (PO)
–Parenteral• Intramuscular (IM)
• Subcutaneous (SC or SQ)
• Intravenous (IV)
• Inhalation
Packaging
• Packaging and preparations – Vials
– Ampules
– Self-contained systems or syringes
– Nebules
Solid Drugs
– Administered orally or rectally
• Pills
• Powders
• Capsules
• Tablets
• Suppositories
Inhalants
–Nebulizers
–Metered-dose aerosols
–Turbo inhalers
–Vaporizers
Distribution
• Several factors affect distribution:
• Cardiovascular function
• Regional blood flow
• Drug storage reservoirs
• Physiological barriers
Biotransformation
• Biotransformation has two effects:– It can transform the drug into a more or less
active metabolite– It can make the drug more water soluble (or
less lipid-soluble) to facilitate elimination
Biotransformation
• Can activate metabolites to make the drug active (prodrugs)
• Many processes occur in the liver– First-pass effect– Body detoxifies and disposes of
toxins and excess drug by increasing water solubility
Basics
• Drugs are eliminated in either their original form or as metabolites– Drug excretion is the movement of a drug or
its metabolites from the tissues back into circulation and from secretion into organs of excretion
Elimination
• Can be affected by– Drug half-life– Accumulation– Clearance– Onset, peak, and
duration
Therapeutic Index
• Medication must reach a certain concentration at the target tissue to be effective
• Medication must reach a certain concentration at the target tissue to be effective
Therapeutic index
Therapeutic threshold
Therapeutic Index
• Dose calculation• ED50
• LD50
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Receptors
Receptors
• Mechanism of Action: how a drug works– Drug action
– Drug effect
Receptors
• Drug receptors: proteins present on cell membrane to which a drug must bind in order to elicit a desired response
Receptors
• Receptors are classified based on effects – Agonist– Antagonist
• Competitive antagonist• Noncompetitive antagonist
• A drug attached to a receptor site displays affinity
Receptors
• Efficacy: the power of a drug to produce a therapeutic effect– Agonists have affinity and
efficacy– Antagonists have affinity but not
efficacy
• Drug potency: relative amount of drug required to produce the desired response
Receptors
• How do drugs bind to receptor sites?– Ionic bonds– Hydrogen bonds– Hydrophobic bonds– Van der Waals forces– Covalent bonds
Receptors
• Receptor sites– Several drugs may bind to the same receptor
site, thus creating different responses by the cells
– Two main functions• Ligand binding• Message propagation
© 2006 The McGraw Hill Companies
Neurotransmitters
Neurotransmitters
• The nervous system is the body’s control system, regulating all bodily function via electrical impulses
• What are the two main parts of the central nervous system that drugs can affect?
Neurotransmitters
• Two divisions:– Central Nervous System (CNS)– Peripheral Nervous System (PNS)
Neurotransmitters
NeurotransmittersOrgan Sympathetic stimulation Parasympathetic stimulation
Heart Increased rate, force
Decreased rate, force
Lungs Bronchodilation Bronchoconstriction
Kidneys Decreased output None
Systemic blood vessels
Constricted – dilated –
None
Liver Glucose release Glycogen synthesis
Blood glucose Increased None
Pupils Dilated Constricted
Basal metabolism Increased up to 100%
None
Skeletal muscle Increased strength None
Neurotransmitters
• Nerves of the autonomic nervous system exit the CNS and enter autonomic ganglia
Neurotransmitters
• No connection exists between two nerve cells or a nerve cell and its target organ; instead there is a space called a synapse
• Neurotransmitters are specialized chemicals that conduct impulses between nerve cells or between a nerve cell and an organ
Neurotransmitters
• Neurotransmitters of ANS:– Acetylcholine (Ach)– Norepinephrine (NE)
• Synapses:– Cholinergic synapses: use acetylcholine– Adrenergic synapses: use norepinephrine
Neurotransmitters
• What is the action of an adrenergic drugs?
• What is the action of a cholinergic drug?
Neurotransmitters
• Sympathetic Nervous System– Arises from the thoracic and lumbar
regions of the spinal cord– Results in direct stimulation of adrenal
medulla and release of norepinephrine (noradrenaline) and epinephrine (adrenaline)
Neurotransmitters
• Sympathetic Nervous System– Stimulation ultimately results in release of
norepinephrine from postganglionic nerves– Sympathetic stimulation also results in
release of epinephrine and norepinephrine from the adrenal medulla
– What is/are the chemical mediators of the SNS?
Neurotransmitters
• Types of sympathetic receptors– What is the action of adrenergic receptors?
• Alpha1 (1)
• Alpha2 (2)
• Beta1 (1)
• Beta2 (2)
– Of dopaminergic receptors?
NeurotransmittersReceptor Actions
alpha1 (1) Peripheral vasoconstriction, increased contractile force, decreased rate
alpha2 (2) Peripheral vasoconstriction
beta1 (1) Increased heart rate, contractile force and automaticity
beta2 (2) Peripheral vasodilation, bronchodilation, uterine smooth muscle relaxation
dopaminergic Renal vasodilation and mesenteric vasodilation
Neurotransmitters
• Sympathomimetics: medications that stimulate the sympathetic nervous system
• Sympatholytics: medications that inhibit the sympathetic nervous system
Neurotransmitters
• The Parasympathetic Nervous System– Arises from the brain stem and sacral
segments of the spinal cord– Synapse in parasympathetic ganglia
– What is/are the chemical mediators of the PNS?
Neurotransmitters
• Stimulation of the parasympathetic nervous system results in:– Pupillary constriction
– Secretion by digestive glands
– Increased smooth muscle activity along GI tract
– Bronchoconstriction
– Reduction in heart rate and contractile force
Neurotransmitters
• Parasympatholytics: medications that block the actions of the parasympathetic nervous system
• Parasympathomimetics: medications that stimulate the parasympathetic nervous system
© 2006 The McGraw Hill Companies
Homeostasis and Balance
Homeostasis and Balance
• Our bodies require constant regulation in order to maintain balance and control
© 2006 The McGraw Hill Companies
Drug Names and
References
Drug Names and References
• Drug Classification– Prescription (Rx)
– Over-the-counter (OTC)• Herbal
Drug Names and References
• Drug Names– Official: generally same as generic name
• meperidine hydrochloride, USP
– Chemical: anatomic and molecular structure• Ethyl 1-methyl-4-phenylisonipecotate
hydrochloride
Drug Names and References
• Drug Names– Generic: abbreviated version of chemical
name• meperidine hydrochloride
– Trade: name based on chemical name or problem used to treat
• Demerol hydrochloride• What is another term for a drug’s trade name?
Sources of Drug Information
• Using multiple sources may provide the best information
• United States Pharmacopia (USP)• National Formulary (NF)• American Hospital Formulary Service• Physician’s Desk Reference (PDR)• Packaging inserts, as required by law
Drug Names and References
• A process must be approved by the FDA
• Studies take place in four phases– Preclinical testing, research, and development– Clinical research and development– NDA Review– Postmarketing surveillance
Drug Names and References
• Bringing a drug to market is a process that takes several years and must be approved by the U.S. Food and Drug Administration (FDA)
Drug Names and References
• Studies take place in four phases– Preclinical testing, research and development– Clinical research and development– NDA Review– Postmarketing surveillance
Drug Names and References
• New Drug Development
–Phase I
–Phase II
–Phase III
–Phase IV
Drug Names and References
• New Drug Development – Orphan Drugs
• Drugs not developed or adopted
Unlabeled Uses of Drugs
• FDA only accepts a new drug for the indications in which phase II and III clinical studies have shown it to be effective.
• Indications approved (labeled)• Not approved (unlabeled)
Drug Names and References
• Unlabeled uses of drugs– FDA recognizes that a drug’s labeling does
not always contain the most current information on usage
© 2006 The McGraw Hill Companies
Patient Medication Rights
Patient Medication Rights
• What are the six “rights” of patient medication administration that ensure safe, proper, and effective administration?
Patient Medication Rights
1. Right patient
2. Right medication
3. Right dose
4. Right route
5. Right time
6. Right documentation
© 2006 The McGraw Hill Companies
Classifying Medications
AHA Classes of Recommendations for Drug Therapies
• Class I
Benefit >>> Risk
– Procedure/treatment or diagnostic test/assessment should be performed/administered
Table 15-7
AHA Classes of Recommendations for Drug Therapies
• Class IIaBenefit >>RiskIt is reasonable to perform procedure/administer treatment or perform diagnostic test/assessment.
Table 15-7
AHA Classes of Recommendations for Drug Therapies
• Class IIbBenefit RiskProcedure/treatment or diagnostic test/assessment may be considered.
Table 15-7
AHA Classes of Recommendations for Drug Therapies
• Class IIIRisk Benefit Procedure/treatment or diagnostic test/assessment should not be performed/administered. It is not helpful and may be harmful.
Table 15-7
AHA Classes of Recommendations for Drug Therapies
• Class Indeterminate– Research is just getting started– Continuing area of research– No recommendation until further research
(e.g., cannot recommend for or against)
Table 15-7
Classifying Medications
• Classified with other similar medications with the same effects– Body system/disease used to treat– Chemical group– Receptor binding site
© 2006 The McGraw Hill Companies
What Paramedics Need to Know About Drugs
What Paramedics Need to Know About Drugs
• Comprehensive drug list based on protocol– Be familiar with AHA Guidelines for
treating cardiac patients– Know local protocol and drugs used in
your region
Need to Know
• Components of a drug
profile
– Names
– Classification
– Mechanism of action
– Indications
– Pharmacokinetics
What Paramedics Need to Know About Drugs
• Components of a drug profile– Side effects/adverse reactions
– Contraindications
– Dosage
– How supplied
– Special considerations
Need to Know
• Special considerations in drug therapy– Pediatric patients– Geriatric patients– Pregnant and lactating
patients
Need to Know
• Use care administering medications
• Follow the medication order
What Paramedics Need to Know About Drugs
• Preparation involves selecting the appropriate sized needle and syringe
• No compensation for dead space is necessary when drawing up medications
What Paramedics Need to Know About Drugs
• Use different needles when reconstituting medication to be drawn up
• Use caution when mixing drugs in one syringe
• ALWAYS use sterile technique
Need to Know
• Medical control– As a paramedic, you operate under the
licensure of a medical director who is responsible for all of your actions
– The medical director determines which drugs you will administer and the routes by which they are given
Need to Know
• Reduce the potential for contamination
• Identify allergies prior to contacting hospital
• Obtain vital signs
• Obtain and confirm/repeat order
• Write the order and the time
Need to Know
• Select the proper medication
• Inspect the medication
• Confirm the order and medication
• Six rights of administration
• Record drug, dose, volume, route, and time, and obtain vital signs and effects
What Paramedics Need to Know About Drugs
• Storage and handling considerations– USP28-NF23, PF30 (6), p. 2118
• “Storage of Drugs in Emergency Medical Services (EMS) Vehicles”
• Narcotics and controlled substances should be secured according to local protocols
What Paramedics Need to Know About Drugs
• Legal regulations, standards, and legislation– International controls
• United Nations World Health Organization provides technical assistance and encourages new research for drug use
Need to Know
• Legal regulations, standards, and legislation– Controls in the U.S.
• Testing (animals studies and clinical patient trials)
• Legislative control
Need to Know
• Legal regulations, standards, and legislation– “Truth in labeling”
• Why might “truth in labeling” be important?
Need to Know
• Legal regulations, standards, and legislation– Narcotics
• Harrison Narcotic Act, 1914• Comprehensive Drug Abuse Prevention and Control
Act, 1970
Schedule of Controlled DrugsCategory Examples
Schedule INo recognized medical use;
high abuse potential
Opiates (heroin), hallucinogens (LSD), depressants (methaqualone)
Schedule IIWritten prescriptions required;
no telephone renewals
Opiates (codeine, morphine, meperidine), stimulants (amphetamines), depressants
Schedule IIIPrescriptions rewritten after six months or five refills
Opiates (codeine <1.8 g/dl), stimulants, depressants, anabolic steroids
Schedule IVPrescriptions rewritten after six months or five refills
Opiates (propoxyphene), stimulants, depressants (chloral hydrate)
Schedule VAny nonnarcotic medication, OTC
Small amounts of opiates when uses as antitussives or antidiarrheals
Need to Know
• Legal regulations, standards, and legislation– Controlled Substances Act, 1970
Need to Know
• Legal regulations, standards, and legislation– Canadian drug legislation
• Under direct control of Department of National Health and Welfare
• Food and Drug Act, 1941• Canadian Food and Drugs Act, 1953
Need to Know
• Legal regulations, standards, and legislation– Canadian Narcotic Control Act and Regulations
• Canadian Narcotic Control Act, 1965– Restricts sale, possession, and use of narcotics– Restricts narcotic distribution to authorized personnel
Need to Know
• Legal regulations, standards, and legislation– Drug Standards
• United States Pharmacopeia (USP) is official standard to maintain uniformity
Need to Know
• Important pharmacological terminology
– What is antagonism?
– What is cumulative action?
– What is potentiation?
– What is synergism?
Need to Know
• Important pharmacological terminology
– Contraindications
– Hypersensitivity
– Idiosyncrasy
– Side effects
– Untoward effects
Need to Know
• Important pharmacological terminology
– Bolus
– Indication
– Therapeutic action
– Tolerance
Need to Know
• Important pharmacological terminology
– Depressant
– Habituation
– Refractory
– Stimulant
© 2006 The McGraw Hill Companies
Pre- and Postmedication Administration
Procedures
Pre- and Postmedication Administration Procedures
• Premedication procedures– Obtain a complete SAMPLE history– Obtain a full set of vital signs– Complete a detailed exam– Contact medical control for authorization
Pre- and Postmedication Administration Procedures
• Postmedication procedures– Document– Obtain a full set of vital signs– Complete a detailed exam– Ongoing assessment
Summary
• In order to deliver exceptional patient care, the paramedic must have a basic understanding of the responsibilities and scope of management prior to administration of any drug
© 2006 The McGraw Hill Companies
Classifications
Street Secret
• Most drugs within the same class have the same suffix; this name generally only applies to the generic name– Beta blockers: –olol– Antihyperlipidemics: –statin– ACE inhibitors: –pril– Calcium channel blocker: –ipines– Opiods: –ine, –one
Street Secret
• Shortcut for remembering what types of doses cardiac drugs have (works for all ACLS drugs)– If the drug begins with a consonant, it is a
two-part dose for normal administration:• Lidocaine—mg/kg• Cardizem—mg/kg• Procainamide—mg/min
Street Secret
• Shortcut for remembering what types of doses cardiac drugs have (works for all ACLS drugs)– If the drug begins with a vowel, it is a one-part
dose:• Epinephrine—mg• Adenosine—mg• Atropine—mg
– Note: This does not work for drips
Street Secret
• A key to remembering the doses on ACLS drugs is as easy as taking a pulse– The dose for a patient with a pulse is half that
of a patient without a pulse
• Antiarrhythmics• Adenosine
• Amiodarone
• Lidocaine
• Procainamide
ACLS Medications
• Catecholamine-sympathomimetic
• Epinephrine 1:10,000
• Isoproterenol
ACLS Medications
• Inotrope• Digoxin
• Epinephrine 1:10,000
ACLS Medications
• Vasopressors• Dopamine
• Dobutamine
• Epinephrine 1:1 000
• Norepinephrine
• Vasopressin
ACLS Medications
• Calcium channel blockers
• Diltiazem
• Verapamil
ACLS Medications
• Parasympatholytics• Atropine
ACLS Medications
• Mineral/electrolyte• Calcium chloride
• Magnesium sulfate
• Sodium bicarbonate
ACLS Medications
• Endocrine/metabolic enhancing agent
• Vasopressin
ACLS Medications
Classifying Medications
• Analgesics–Nonsteroidal anti-inflammatory
agents (NSAID)• Ibuprofen
• Ketorolac
Classifying Medications
• Analgesics–Narcotics
• Butorphanol
• Fentanyl
• Meperdine
• Morphine sulfate
• Nalbuphine
Classifying Medications
• Analgesics–Other analgesics
• Acetaminophen
Classifying Medications
• Anaphylaxis–Antianaphylactic agents
• Epinephrine 1:1 000
• Diphenhydramine
• Hydroxyzine
Classifying Medications
• Anesthetics– Topical anesthetics
• Benzocaine• Cetacaine• Lidocaine topical gel• Procaine• Proparacaine• Tetracaine
Classifying Medications
• Anesthetics–Local anesthetics
• Procaine
• Proparacaine
• Tetracaine
Classifying Medications
• Anesthetics–Inhaled agents
• Nitrous oxide
Classifying Medications
• Antianginal agents–Nitroglycerine
–Nitroprusside
Classifying Medications
• Anticoagulants– Heparin– Warfarin sodium
Classifying Medications
• Anticonvulsants–Anticonvulsants
• Fosphenytoin
• Phenobarbital
• Phenytoin
Classifying Medications
• Anticonvulsants–Benzodiazepine
• Diazepam
• Lorazepam
• Midazolam
Classifying Medications
• Antiemetics–Droperidol
–Prochlorperazine
–Promethazine–Hydroxyzine
Classifying Medications
• Antihypertensives–Antihypertensive
• Clonidine
• Diazoxide
Classifying Medications
• Antihypertensives–ACE Inhibitor (acetylcholinesterase)
• Enalapril
Classifying Medications
• Antihypertensives–Calcium channel blocker
• Nifedipine
Classifying Medications
• Antihypertensives–Vasodilator
• Nitroprusside
Classifying Medications
• Antihypoglycemics–Dextrose
–Glucagon
–Insulin
–Oral glucose paste
Classifying Medications
• Antiplatelet agents–Acetylsalicylic
acid (ASA) or aspirin
Classifying Medications
• Antitoxicologics–Anticholinergic
• Atropine
Classifying Medications
• Antitoxicologics–Antidote
• Cyanide antidote kit
• Methylene blue
• Physostigmine
• Pralidoxime auto injector
Classifying Medications
• Beta blockers–Esmolol
–Labetalol
–Metoprolol
–Propranolol
Classifying Medications
• Diuretics–Diuretic
• Mannitol
Classifying Medications
• Diuretics–Loop diuretics
• Bumetanide
• Furosemide
Classifying Medications
• Fibrinolytics– Alteplase
– Antithrombin III
– Heparin
– Reteplase
– Tenectplase
– Urokinase
Classifying Medications
• Gastric decontaminants– Toxicological agents
• Activated charcoal• Ipecac
Classifying Medications
• Induction agents–Analgesic
• Ketamine
Classifying Medications
• Induction agents–Barbiturate
• Methohexital
• Thiopental
Classifying Medications
• Induction agents–Benzodiazepine
• Midazolam
Classifying Medications
• Induction agents–Hypnotic
• Etomidate
Classifying Medications
• Induction agents–Opiate
• Fentanyl
Classifying Medications
• Narcotic and benzodiazepine antagonists–Flumazenil
–Naloxone
–Nalmefene
Classifying Medications
• Nasal decongestants– Oxymetazoline
nasal – Phenylephrine
nasal
Classifying Medications
• Neuroleptics–Antipsychotics
• Chlorpromazine
• Haloperidol
Classifying Medications
• Neuroleptics–Antiemetic
• Droperidol
Classifying Medications
• Paralytics– Neuromuscular blocking agents (NMBA)
• Depolarizing– Succinylcholine
• Nondepolarizing– Mivacurium– Pancuronium– Vecuronium
Classifying Medications
• Postpartum agents–Oxytocin
Classifying Medications
• Respiratory agents–Bronchodilators
• Sympathomimetic (adrenergic)– Beta2 selective
» Albuterol» Isoetharine» Terbutaline
Classifying Medications
• Respiratory agents–Bronchodilators
• Sympathomimetic (adrenergic)– Nonselective
» Epinephrine » Epinephrine (inhaled)» EpiPen Autoinjector/EpiPen Jr» Metaproterenol» Racemic epinephrine
Classifying Medications
• Respiratory agents–Bronchodilators
• Combination agents– Albuterol/ipratoprium
combination
Classifying Medications
• Respiratory agents–Bronchodilators
• Methylxanthine (xanthine) derivative– Aminophylline
Classifying Medications
• Respiratory agents– Bronchodilators
• Parasympatholytic (anticholinergic)
– Ipratoprium
Classifying Medications
• Steroids–Dexamethasone
–Hydrocortisone
–Prednisone
–Methylprednisolone sodium succinate
Classifying Medications
• Tocolytics–Magnesium sulfate
–Terbutaline
Classifying Medications
• Vasopressors–Adrenergics
–Sympathomimetics
–Catecholamines
Classifying Medications
• Vitamins and electrolytes– Calcium chloride
– Calcium gluconate
– Magnesium sulfate
– Potassium chloride
– Sodium bicarbonate
– Thiamine