General Pharmacological Principles Module A
Objectives • The student will be able to: • List three sources of drugs. • List the components of a proper medication order. • Define the commonly used abbreviations. • List the routes of medication delivery. • Define "parental administration" and list three types of parental administration. • List the four routes of medication delivery via inhalation. • List three types of nebulizers used to deliver respiratory medication. • Given a route of administration, explain the safety requirements associated with drug administration.
Objectives • The student will be able to: • Explain two ways to confirm proper patient identification prior to giving a medication. • State the change in pulse rate needed to terminate a respiratory treatment. • Describe how the effectiveness of bronchodilators can be objectively measured? • List the items that should be documented in the patients chart following each treatment. • Describe the procedure you would follow in the event of an adverse reaction. • Define terms typically found on a package insert for a drug. • Describe how most drugs are metabolized and excreted.
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Definition of Pharmacology • Pharmacology - The study of drugs (chemicals) including their origins, properties, and interactions with living organisms.
Are these drugs? • Aspirin • Mint • Vodka • Vitamins • Black Cohosh
Drug Sources • Chemical synthesis • Most common • Recombinant DNA • Animal • Plant • Mineral
FDA • Federal agency • Regulates drug testing • Approves new drugs • http://www.fda.gov/
Drug Approval • Can take up to 12 years and over 200 million dollars. • Only 1 in 10,000 chemicals are approved.
Steps for Drug Approval • Identify the chemical structure • Animal studies – toxicology studies • Investigational New Drug Approval • Phase I: Healthy volunteers • Phase II: Volunteers who have the disease • Phase III: Large multi-center study • New Drug Application – NDA is filed with the FDA and upon approval it is released for general use. Reporting system in place for 6 months
Source of Drug Information • PDR – Physician Desk Reference • USP – United States Pharmacopoeia • National Formulary • Hospital Formulary • FDA Website! • http://www.fda.gov/
Study of Drugs • Generic and Trade Names • Classification • Indications • Actions • Adverse reactions (side effects) • Contraindications • Dosage
Naming Drugs • Chemical Name: Reflects the chemical structure. • 4-(5-cyclopentyloxy-carbonylamino 1-methyl-indo-3 ylmethyl) • Code Name: Name assigned by a manufacturer to an experimental chemical that shows potential as a drug (SCH 1000).
Naming Drugs • Generic Name: Based on the drugs chemical structure. • Assigned by the USAN Council • Example: isoproterenol • Trade Name: Name given by the manufacturer. • A generic drug can have 2 or more trade names. • Also called brand name. • Example: Isuprel
Trade Names Beta Blockers propranolol atenolol metoprolol Neuromuscular blocking agents pancuronium vecuronium atracurium Names of drugs contains clues Slo-Bid Nasalcort DuoNeb
Prescriptions for Medication Orders • Patient’s Name • Date • Name of the drug • Dosage of drug and amount • Concentration if appropriate • Route of administration (delivery device) • Frequency or Schedule • Number of days if appropriate • Any additional instructions • Peak flows before and after therapy • Monitor tidal volume during IPPB treatment • Signature of Physician
Examples: • John Smith 12/23/89 IPPB therapy with 0.25 mL of 1% Bronkosol and 3 mL Normal Saline four times a day x 3 days. Dr. James Jones • Jack Doe 3/30/99 SVN therapy with 0.3 mL of 5% Alupent and 2 mL of Normal Saline every four hours around the clock. Peak flow before and after treatment. Dr. James Jones
Example • Karen Johnson 4/28/96 MDI Proventil 2 puffs three times a day. Administer with spacer Dr. James Jones
Abbreviations • Lots of changes over the last few years. • Due to errors in prescribing, many abbreviations have been eliminated based upon JCAHO recommendations (handout). • Many institutions have specific rules that go beyond JCAHO recommendations (handout).
Frequency Abbreviations • BID: Twice a day • TID: Three times a day • PRN: When necessary, as needed • STAT: Immediately
Eliminated Frequency Abbreviations • Some others that have been eliminated: • QOD: Use “Every other day” • QD: Use “daily” • QID: Four times a day • Q4: Every four hours • Q3: Every three hours • Q2: Every two hours • Q4 ATC: Every four hours around the clock • Q4 WA: Every four hours while awake • Q4 PRN: Every four hours as needed • H.S: Use at “bedtime”
Other commonly used abbreviations: • NS: Normal Saline • : With • : Without • a.c.: Before Meals • p.c.: After Meals • mL: Milliliters • gtt: drop • qs: Quantity sufficient (as much as required) • PO: By mouth, orally
Other commonly used abbreviations: • MDI: Metered Dose Inhaler • IPPB: Intermittent Positive Pressure Breathing • SVN: Small Volume Nebulizer • SPAG: Small Particle Aerosol Generator • Rx: Prescription or “take” • IM: Intramuscularly • IV: Intravenous • DPI: Dry Powder Inhaler • Tx: Treatment
Other commonly used abbreviations: • NPO: Nothing by mouth • OTC: Over the Counter • FDA: Food and Drug Administration • PDR: Physician Desk Reference • BS: Breath Sounds • PF: Peak Flow • PEFR: Peak Expiratory Flow Rate
Other Eliminated Abbreviations • D/C: (eliminated) Discontinued • cc (eliminated): Cubic Centimeters
5 “Rights” • Right Drug • Right Dose • Right Patient • Patient’s wrist band • Right Time • Right Route • Also • Expiration Date • Allergies • Timely documentation
Routes of Medication Delivery • Oral (Enteral) Route • Tablet • Capsule • Pill • Powder • Solutions • Elixirs • Syrups • Emulsions/gels
Routes of Medication Delivery • Parenteral Route(route comprising routes that bypass the alimentary tract, i.e. injectable) • Intradermal • Subcutaneous • Intramuscular • Intravenous • Intra-arterial • Intra-spinal • Intraosseous (into the tibia or sternum)
Routes of Medication Delivery • Topical • Transdermal • Creams and gels • Sublingual (under the tongue) • Enteral • Rectal • Inhalation • MDI • Aerosol (SVN, USN) • DPI • IPPB
Routes of Medication Delivery • Aerosol Therapy • Small volume nebulizers • Ultrasonic nebulizers • Large volume nebulizers • SPAG • Heart Nebulizer • IPPB • Metered Dose Inhalers • Dry Powder Inhalers
SMALL VOLUME NEBULIZER (SVN) LARGE VOLUME NEBULIZER SMALL PARTICLE AEROSOL GENERATOR (SPAG)
DRY POWDER INHALER (DPI) METERED DOSE INHALER (MDI)
Continuous Nebulization • Occasionally, the nebulized medication must be administered over an extended period of hours instead of minutes. • A nebulizer can be adapted to other oxygen delivery equipment to facilitate this process.
Advantage of Aerosolized Agents • Dosage is smaller. • Less side effects and less severe side effects. • Rapid Onset. • Drug delivery is targeted to the respiratory system. • Painless, safe and convenient. • Patients can administer medication themselves.
Medications Given by RCP • Bronchodilators • Mucolytics • Steroids • Non-Steroidal Anti-inflammatory • Mast Cell Stabilizers • Leukotriene Inhibitors • Anti-Infective Agents
Medications given by RCP • Nicotine Replacement Therapy • Artificial Surfactants • Topical Anesthetics • Lidocaine • Gases • Oxygen • Nitric Oxide • He/O2 (Heliox) • Morphine (?)
Objectives • State the change in pulse rate needed to terminate a respiratory treatment. • Describe how the effectiveness of bronchodilators can be objectively measured? • List the items that should be documented in the patients chart following each treatment. • Describe the procedure you would follow in the event of an adverse reaction. • Define terms typically found on a package insert for a drug. • Describe how most drugs are metabolized and excreted.
What is the difference between Q4 PRN, Q4 WA, and PRN? • Q4 PRN: Every four hours as needed • Q4 WA: Every four hours while awake • PRN: When necessary, as needed
Drug Metabolism and Excretion • Pharmacokinetics: The movement (kinesis) of the drug throughout the body. • Absorption • Limited by disintegration • Bioavailability: The amount of drug that has been absorbed into the circulation. • Distribution • Metabolism • Liver • Elimination • Kidney • GI Tract (feces), Skin, Pulmonary System
Definition of Terms • Selectivity – The extent to which a drug acts at one specific site or receptor. • When binding occurs: • Ion channel open/closed • Biochemical messengers are activated. • Normal cellular function is turned on or off.
Definition of Terms • Racemic– A drug which contains two isomers (same chemical components, only bonded differently). • Agonist – A drug or chemical that binds to a corresponding receptor and initiates a cellular effect or response – Example: b2 agonist • Agonists have an affinity for a receptor site. • Antagonist - A drug which binds with a receptor but do not cause activation of the receptor. • Explains why some drug’s action is less effective or blocked in the presence of another drug.
Definition of Terms • Drug Affinity – A measure of the tendency of a drug to combine with a particular receptor site. • Drug Potency – The amount of drug required to produce the response desired. • A more potent drug would require a lower dose to proved a desired effect. • Drug Efficacy – The peak or maximum biologic effect.
Definition of Terms • Tolerance - Increasing amounts of drug are needed to produce the same effect. • Loss of effectiveness. • Tachyphylaxis - A rapidly decreasing response to a drug following administration of the initial doses. • Desensitization - Loss of tissue responsiveness that can occur with drug exposure. • Placebo - An inactive substance resembling a medication that may be given experimentally or for its psychological effects
Definition of Terms • Additive– The sum of the effects of two drugs given together is equal to each of them given separately but at the same time (1+1 = 2). • Synergism– The joint effect of two drugs is greater than the algebraic sum of their individual effects (1+1 = 3). • albuterol + ipratropium bromide • Potentiation- The effect of two drugs given together where one drug has no effect but increases the response of the other drug (1 + 0 = 2)
Definition of Terms • Half Life of a drug – The time required to eliminate 50% of the drug from the body after absorption and distribution are complete. • Loading Dose – Administration of an initial higher level of the drug to facilitate a steady state (maximal saturation of the receptors in the body). • Maintenance Dose– Additional drug which is administered after the loading dose that is used to maintain the steady state.
Definition of Terms • Side Effect – Unwanted symptoms which occur after drug administration • Also called adverse drug reaction (ADR) • Cumulation – Occurs when a drugs rate of removal or inactivation is slower than the rate of administration. This can result in toxicity. • Emetic - A substance that induces vomiting. • Activated Charcoal – Used to decrease absorption. • Teratogenicity – A drug’s potential to damage a fetus in utero when given to a pregnant women.