adams ch02 lecture
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PHARMACOLOGY FOR NURSESPHARMACOLOGY FOR NURSESA Pathophysiological ApproachA Pathophysiological Approach
FOURTH EDITIONFOURTH EDITION
Copyright © 2014, © 2011, © 2008 by Pearson Education, Inc.All Rights Reserved
CHAPTER
Drug Classes and Schedules
2
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Drug Are Organized in Two WaysDrug Are Organized in Two Ways
• Therapeutic classification• Pharmacologic classification
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Therapeutic Classification of DrugsTherapeutic Classification of Drugs
• Based on what the drug does clinically• Examples
– Anticoagulants– Antidepressants– Antineoplastics
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Table 2.1 Therapeutic Classification
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Pharmacologic Classification Pharmacologic Classification of Drugsof Drugs
• Based on the drug's mechanism of action, or how the drug produces its effect– At molecular, tissue, or body-system
level• More specific than therapeutic
classification
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Pharmacologic Classification Pharmacologic Classification of Drugsof Drugs
• Requires understanding of biochemistry and physiology
• May be described with varying degrees of complexity
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Table 2.2 Pharmacologic Classification
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
ExamplesExamples
• Calcium-channel blockers• Diuretics• Adrenergic antagonists
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
““PrototypePrototype”” Drug—Serves as Model Drug—Serves as Model for a Drug Classfor a Drug Class
• Is well understood• Has known action and adverse effects• Is used to compare other drugs in the
same pharmacologic class• May not be the most widely used drug
in its class• Disagreements may exist over which
drug should serve as prototype drug.
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Newer Drugs in the Same ClassNewer Drugs in the Same Class
• Newer drugs in the same class may have replaced the prototype drug's use because they:– Are more effective– Have a more favorable safety profile– Have longer duration of action
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Most Drugs Have Three NamesMost Drugs Have Three Names
• Chemical• Generic • Trade
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Drug Has One Chemical NameDrug Has One Chemical Name
• Assigned using standard nomenclature established by International Union of Pure and Applied Chemistry (IUPAC)
• Describes physical and chemical properties of drug
• Sometimes helpful in predicting a substance's physical and chemical properties
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Drug Has One Chemical NameDrug Has One Chemical Name
• Complicated, difficult to remember and pronounce– Example: chemical name for diazepam:
7-chloro-1, 3-dihydro-1-methyl-5-phenyl-2H-1, 4-benzodiazepin-2-one
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Chemical Group NameChemical Group Name
• Drugs are sometimes classified by a portion of their chemical structure:– Cephalosporins, phenothiazines,
benzodiazepines • Chemical group names can become
invaluable to a nursing student.
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Generic NameGeneric Name
• Assigned by the U.S. Adopted Name Council
• Less complicated and easier to remember
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
A Drug Has One Generic NameA Drug Has One Generic Name
• Used by many organizations – Food and Drug Administration (FDA)– United States Pharmacopoeia– World Health Organization
• Written in lower case• Example: diazepam
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
A Drug Has Several Trade NamesA Drug Has Several Trade Names
• Assigned by company marketing the drug
• Short, easy to remember• Also called proprietary, product, or
brand name
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
A Drug Has Several Trade NamesA Drug Has Several Trade Names
• Drug developer has exclusive rights to name and market a new drug for 17 years in the United States.
• Trade name is capitalized.• Example: a trade name for
diphenhydramine is Benadryl.
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Trade NamesTrade Names
• After 17 years, competing companies may sell a generic equivalent drug, sometimes using a different name, which the FDA must approve.
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Trade NamesTrade Names
• Trade names can be difficult because many drugs contain similar ingredients.– A combination drug contains more than
one active ingredient.– The rule of thumb is that the active
ingredients in a drug are described by their generic name, which is lowercase.
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Table 2.3 Examples of Brand-Name Products Containing Popular Generic Substances
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Rights IssuesRights Issues
• A pharmaceutical company with exclusive rights to a drug often prices it very high.
• When rights end, competing companies offer the generic form of the drug for less money.
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Rights IssuesRights Issues
• Depending on the state, a pharmacist may offer the generic form of a prescribed drug, or may only be allowed to dispense the exact form written in the prescription.– Drug companies lobby against easy
substitution of generic drugs; consumer advocates lobby the opposite.
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Generic vs. Brand-Name DrugsGeneric vs. Brand-Name Drugs
• It is difficult to tell if there is a difference in effect between two forms of a drug, even if dosage is the same.– Inert ingredients may be different.
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Generic vs. Brand-Name DrugsGeneric vs. Brand-Name Drugs
• Key to comparison is bioavailability—the physiologic ability of the drug to reach its target cells and produce its effect.
• Measuring how long a drug takes to exert its effect gives a crude measure of bioavailability.
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Some States Have a Negative Some States Have a Negative Formulary ListFormulary List
• List of trade-name drugs that pharmacists may not dispense as generic-drug substitutes
• Claim that there are differences in bioavailability between generic and trade-name drugs
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Some States Have a Negative Some States Have a Negative Formulary ListFormulary List
• Pharmaceutical companies and some health care practitioners support list.
• Claim that differences could adversely affect patient outcomes
• Laws relating to these lists often change.
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Some States Have a Negative Some States Have a Negative Formulary ListFormulary List
• Consumer advocate groups often argue against the Negative Formulary List because of cost savings of generic drugs.
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Addiction and DependenceAddiction and Dependence
• Addiction– The overwhelming feeling that drives a
person to use a drug repeatedly• Dependence
– A physiologic or psychologic need for a substance
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Addiction and DependenceAddiction and Dependence
• Physical dependence– An altered physical condition caused by
the adaptation of the nervous system to repeated drug use
• When the drug is no longer available, the individual expresses physical signs of discomfort known as withdrawal.
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Addiction and DependenceAddiction and Dependence
• Psychologically dependent– Little physical discomfort when drug is
withdrawn, but intense compelling desire to continue use
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Controlled SubstancesControlled Substances
• Controlled substances are drugs that:– Are restricted by the Controlled
Substances Act of 1970– Are frequently abused– Have a high potential for addiction or
dependence– Have restricted use– Are placed into one of five schedules
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Controlled Substance Controlled Substance Act of 1970Act of 1970
• Also known as Comprehensive Drug Abuse Prevention and Control Act
• Restricts use of drugs with potential for abuse
• Restricted drugs placed into the five schedules
• Hospitals and pharmacies must maintain complete records of scheduled drugs.
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Drug Enforcement Administration (DEA) Drug Enforcement Administration (DEA) Regulates Controlled Substance ActRegulates Controlled Substance Act
• Hospitals and pharmacies must register with DEA.– Must use assigned registration number
to purchase scheduled drugs
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Controlled SubstancesControlled Substances
• Anyone convicted of unlawful manufacturing, distributing, and dispensing of controlled substances faces severe penalties.
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Scheduled DrugsScheduled Drugs
• Drugs that have a significant potential for abuse are placed into five categories called schedules.– Schedule I drugs have the highest abuse
potential, Schedule V the lowest.
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Table 2.4 Examples of Brand-Name Products Containing Popular Generic Substances
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Schedule I DrugsSchedule I Drugs
• Restricted to situations of medical necessity, if allowed at all
• Little or no therapeutic value; mostly used for research
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Examples of Schedule I DrugsExamples of Schedule I Drugs
• Heroin• LSD• Methaqualone
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Schedule II-V DrugsSchedule II-V Drugs
• May be dispersed only in cases where therapeutic value has been determined
• Some Schedule V drugs may be dispersed without a prescription.
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Not All Drugs with Abuse Potential Not All Drugs with Abuse Potential Are RegulatedAre Regulated
• Tobacco, alcohol, and caffeine
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Schedule II DrugsSchedule II Drugs
• High abuse potential• High potential for physical and
psychological dependence• Therapeutic use with prescription• Some drugs no longer used
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Schedule II Drugs Have More Schedule II Drugs Have More Restrictions Restrictions
• Need special order form to obtain• Orders must be written.• Orders must be signed by health care
provider.• Telephone orders to pharmacies are not
permitted.• No refills are permitted; patient must
see health care provider first.
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Examples of Schedule II DrugsExamples of Schedule II Drugs
• Morphine• PCP• Cocaine• Methadone• Methamphetamine
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Schedule III DrugsSchedule III Drugs
• Moderate abuse potential• Moderate physical dependence• High potential for psychological
dependence• Therapeutic use with prescription
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Examples of Schedule III DrugsExamples of Schedule III Drugs
• Anabolic steroids• Codeine with aspirin or Tylenol• Hydrocodone with aspirin or Tylenol• Some barbiturates
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Schedule IV DrugsSchedule IV Drugs
• Lower abuse potential• Lower potential for physical and
psychological dependence• Therapeutic use with prescription
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Examples of Schedule IV DrugsExamples of Schedule IV Drugs
• Dextropropoxyphene• Pentazocine• Meprobamate• Diazepam• Alprazolam
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Schedule V DrugsSchedule V Drugs
• Lowest abuse potential• Lowest physical and psychological
dependence• Therapeutic use without prescription• Examples:
– OTC cough medicines with codeine
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Teratogenic Drug ClassificationTeratogenic Drug Classification
• Five categories of risk that a drug poses to a fetus in the case of a pregnant woman taking the drug
• A, B, C, D, and X
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Category A DrugsCategory A Drugs
• Controlled studies in women fail to show a risk to the fetus, and the possibility of fetal harm appears unlikely.
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Category B DrugsCategory B Drugs
• Animal reproduction studies have not shown a fetal risk or adverse effect. Risks have not been confirmed in controlled studies in women.
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Category C DrugsCategory C Drugs
• Either studies in animals have revealed adverse effects on the fetus and there are no controlled studies in women or studies in women and animals are not available.
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Category D DrugsCategory D Drugs
• There is confirmation of human fetal risk, but the benefits from use in pregnant women may be acceptable despite the risk—for example, in a life threatening situation.
Pharmacology for Nursing: A Pathophysiology Approach, Fourth EditionMichael Patrick Adams | Leland N. Holland | Carol Urban
Category X DrugsCategory X Drugs
• Animal and human studies have shown fetal abnormalities.
• The drug is contraindicated in women who are or may become pregnant.