NR 293 Exam 1 Study Guide

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NR 293 Exam 1 Study Guide Latest 2023 / 2024

Chapter 2

 Define the common terms used in pharmacology

• Pharmacokinetic- the study of what the body does to the drug; involves the processes of

absorption, distribution, metabolism, and excretion; the study of what happens to a drug from the time it is put into the body until the parent drug and all metabolites have left the body; represent the drug absorption into, distribution and metabolism within, and excretion from the body

• Pharmacodynamics- the study of what the drug does to the body; involves drug–

receptor relationships.

• First-pass effect- initial metabolism in the liver of a drug absorbed from the GI tract

before the drug reaches systemic circulation through the bloodstream; reduces the bioavaibility of less than 100%, whereas drugs administered by the intravenous route are 100% bioavailable

• Bioavaibility- a measure of the extent of a drug absorption for a given drug and route

(from 0% to 100%)

• Protein-binding
• Onset of action- time required for a drug to elicit a therapeutic response after dosings
• Peak Effect – the time required for a drug to reach its max. therapeutic response
• Duration of action- the length of time the concentration of a drug in the blood or tissues

is sufficient to elict a response

• Half-life – in pharmacokinetics, the time required for half of an administered dose of

drug to be eliminated by the body, or the time it takes for the blood level of a drug to be reduced

• Therapeutic index- ratio btwn toxic and therapeutic concentrations of a drug
• Trough level- lowest blood level; the lowest concentration of a drug reached in the body

after it falls from its peak level, usually measured in blood sample for therapeutic drug monitoring

• Peak level- highest blood level; done usually at 12

th level after 3 rd dose; the max.concentration of a drug in the body after administration, usually measured in a blood sample for therapeutic drug monitoring

• Agonist- drug that binds to and stimulates the activity of one or more receptors in the

body

• Antagonist- drug that binds to and inhibits the activity of one or more receptors in the

body; also called inhibitors

 Type of therapy:

• Acute therapy- often involves more intensive drug treatment and implemented in acutely

ill (those with rapid onset of illness) or critically ill; often needed to sustain life or treat disease

 Ex: vasopressors to maintain BP and cardiac output after open heart surgery

 Ex: intensive chemotherapy for pt with newly diagnosed cancer

• Maintenance therapy- doesn’t eradicate problems the pt may already have but will

prevent progression of a disease or condition; used for treatment of chronic illnesses  Ex: HTN it will maintain the pt’s BP within given limits which prevents certain 1 / 3

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end-organ damage

 Ex: oral contraceptives for birth control

• Supplemental therapy- or replacement therapy; supplies body with a substance needed

to maintain normal function; substance may be needed bc it cannot be made by the body or bc it is produced in insufficient quantity

 Ex: administration of insulin to diabetic pt’s

 Ex: iron to pts w/ iron-deficiency anemia

• Palliative therapy- make pt as comfortable as possible; focuses on providing pts w/

relief from symptoms, pain, and stress of a serious illness; goal is to improve quality of life for both pt and family; typically used in the end stages of an illness when attempts at curative therapy have failed; it can be provided along with curative treatment  Ex: use of high dose opioid analgesics to relieve pain in the final stages of cancer

• Supportive therapy- maintains integrity of body functions while the pt is recovering

from illness/trauma  Ex: provision of fluids and electrolytes to prevent dehydration in a pt w/ influenza who is vomiting and has diarrhea  Ex: administration of fluids, volume expanders, or blood products to a pt who lost blood during surgery

• Prophylactic therapy- drug therapy provided to prevent illness or other undesirable

outcome during planned events  Ex: preoperative antibiotic therapy for surgical procedures. Antibiotic given before incision is made so antibiotic can kill any potential pathogens

 Ex: administration of disease-specific vaccines to individuals traveling to

geographic areas where a given disease is known to be endemic

• Empiric therapy- based on clinical probabilities; involves drug administration when

certain pathologic condition has an uncertain but high likelihood of occurrence based on the pt’s initial presenting symptoms  Ex: use of antibiotics active against the organism most commonly associated with specific infection before results of C+S reports are available

 Drug interaction:

• Additive effect- (1+1=2) when two drugs with similar actions are given together bc their

additive effects so smaller doses of each drug can be given  Ex: combinations of analgesic products antihistamine and opioid combinations (promethazine and codeine) for treatment of cold symptoms

 Ex: acetaminophen and opioid combinations (acetaminophen and oxycodone) for

treatment of pain

• Synergistic effect-when two drugs administered together interact in such a way that their

combined effects are greater than the sum of the effects for each drug given alone (1+1 = greater than 2)

 Ex: combination of hydrochlorothiazide with lisinopril for treatment of HTN

• Antagonistic-occur when the combination of two drugs results in drug effects that are

less than the sum of the effects for each drug given separetly (1+1 = less than 2)  Ex: antibiotic ciprofloxacin is given simultaneously with antacids, vitaminsm iron, or dairy products (these drugs reduce absorption of ciprofloxacin and lead to decreased effectiveness of the antibiotic)

• Incompatibility-commonly used to describe parenteral drugs; occurs when two

parenteral drugs or solutions are mixed together and result is chemical deterioration of one or both of the drugs or the formation of physical precipitate; combination of two such drugs usually produces a precipitate, haziness, or color change in the solution; before administering an IV med always inspect back for precipitate and if bag appears cloudy or visible flecks are seen it must be discarded and not given to pt. Ex: combination of parenteral furosemide and heparin 2 / 3

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 Adverse drug reaction (ADR)- any reaction to a drug that is unexpected and undesirable and occurs at therapeutic drug dosages; caused by processes inside pts body; may or may not be preventable; mild ADR usually doesn’t require change in pt’s drug therapy or other interventions; more severe ADR are likely to require changes to a pts drug regimen; Severe ADR can be permanently or significantly disabling, life threatening, or fatal

• Pharmacologic reactions-extension of a drug’s normal effects in the body;predictable,

well known ADR resulting in minor or no changes in pt management; have predictable frequency and intensity and occurrence is related to dose; usually resolve upon d/c of drug therapy

 Ex: drug that used to lower BP in a pt causes pharmacologic adverse drug

reaction when it lowers the BP to the point that the pt becomes unconscious

• hypersensitivity reaction (allergic reaction)- pt’s immune system is involved; immune

system proteins (immunoglobulins) recognize drug molecule (metabolites) or another ingredient in a drug formulation as dangerous foreign substance and an immune response can occur in which the immunoglobulin proteins bind to drug substance to attempt to neutralize drug; result in mild (skin erythema or mild rash) to life threatening reactions (constriction of bronchial airways and tachycardia)

• idiosyncratic reaction-not the result of known pharmacologic property of a drug or of a

pt allergy but occurs unexpectedly in particular pt; genetically determined abnormal response ot normal dosages of a drug  Other Drug Effects

• Teratogenic- result in structural defects in fetus; drugs capable of crossing the placenta

causes drug induced teratogensis; drugs administered pregnancy can produce diff types of congenital anomalies; most vulnerable 3 rd week of development till after 3 rd mo.

• Mutagenic- permanent changes in genetic composition of living organisms and consist

of alterations in chromosome structure, the number of chromosomes, or genetic code DNA molecule; radiation, viruses, chemicals, and drugs can all act as mutagenic agents in humans; drugs that affect genetic processes are active primarily during cell reproduction (mitosis)

• Carcinogenic- effects are cancer causing effects of drugs, chemicals, radiation, and

viruses

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