Basics

Question 1

Absorption

Answer 1

Getting drug to blood

Question 2

Distribution

Answer 2

• Movement of drug to body’s tissue
• Results in therapeutic and adverse effects

Question 3

Metabolism

Answer 3

Breaking drug down

Question 4

Excretion

Answer 4

Getting drug out of body

Question 5

Factors Influencing Drug Absorption

Answer 5

• Route
• Drug properties
  > molecular size, lipid solubility, pH
• Pt properties
  > surface area of absorptive site, blood flow to site of absorption

Question 6

Oral Route

Answer 6

• Most meds absorped in small intestine
• Due to first-pass metabolism, the oneset of action for most oral drugs is 30-60mins

Question 7

Sublingual

Answer 7

Absorbed into highly vascular tissue under tongue; rapid actions

Question 8

Topical

Answer 8

• Delivers drug directly to affected area
• Minimal systemic absorption

Question 9

Transdermal

Answer 9

• Provides constant rate of drug absorption
• Always apply to intact skin
  > broken skin incrs absorption

Question 10

Intravenous (IV)

Answer 10

• Full strength: immediate onset & fully absorbed; more likely to cause toxic effects
• If admining more than 1 drug at same site, must be compatible

Question 11

Intramuscular (IM)

Answer 11

• Absorbed directly into capillaries in muscle & sent into circulation
• Men more vascular muscles than women; men reach a peak lvl faster than women

Question 12

Subcutaneous (SQ)

Answer 12

• Slowly absorbed; timing of absorption varies depending on fat content & state of local circulation
• Incrd adipose tissue = dcrd absorption (less capillaries)

Question 13

Bioavailability

Answer 13

• IV: 100% absorption, 100% biooavailable
• IM/SQ: 100% absorption, <100% bioavailable
• Oral: <100% absorption, 0-70% bioavailable

Question 14

Factors Affecting Distribution

Answer 14

• Blood flow to organs/tissues
  > areas of rapid perfusion/distribution: heart, liver, kidney, brain
  > areas of slow distribution: muscle, skin, fat
• Ability to cross blood-brain barrier or fetal/placental barrier
• Drug properties
  > Protein binding (albumin); highly protein bound = less available for distribution
  > highly water soluble drugs stay in bloodstream; go more places
  > highly lipid-soluble drugs more readily lipid cell membranes & deposit in adipose tissue

Question 15

Primary Site for Metabolism

Answer 15

• LIVER
• hepatic microsomal enzyme system (P-450 system)
• inactivates/breakdown drug for excretion; some to active form (prodrug)
• changes in hepatic microsomal enzyme can affect drug metabolism

Question 16

Factors Affecting Metabolism

Answer 16

• Metabolic activity may be dcrd in some pts
  > infants & elderly
  > genetic disorders
  > severe liver disease
• Dosages reduced in dcrd liver func to prevent toxicity

Question 17

Nursing Considerations for Metabolism

Answer 17

• Liver disease is a caution/contra when admining certain drugs
• Monitor liver functions to avoid drug toxicity or injury to liver

Question 18

Primary Site for Excretion

Answer 18

• KIDNEY
• Liver/Bowel are secondary
  > drug processed by liver, released into bile, eliminated in feces

Question 19

Factors Affecting Excretion

Answer 19

• Kidney dysfunction
  > drugs not excreted effectively; reach toxic lvls
• Nurse: monitor kidney func to avoid drug toxicity or AKI

Question 20

Older Adult: Physiological Changes of Aging r/t Pharm

cardio
gastro
hepatic
renal

Answer 20

• Cardiovascular: dcrd CO
• Gastrointestinal:
  > incrd gastric pH & dcrd peristalsis
  > dcrd absorption
• Hepatic: dcrd enzyme production & dcrd blood flow to liver
• Renal: dcrd blood flow, GFR, & overall function

Question 21

Older Adult: Pharmacokinetic Alterations - Absorption

Answer 21

Changes can result in dcrd absorption of oral drugs

Question 22

Older Adult: Pharmacokinetic Alterations - Distribution

Answer 22

• Dcrd total body water incrs concentration of med; risk for toxicity
• Dcrd protein (albumin); greater amnt of free drug; risk for toxicity

Question 23

Older Adult: Pharmacokinetic Alterations - Metabolism

Answer 23

Enzyme activity dcrd due to dcrd function; incrd risk for toxicity

Question 24

Older Adult: Pharmacokinetic Alterations - Excretion

Answer 24

Dcrd # of nephrons & GFR; incrd risk for toxicity

Question 25

Anaphylaxis

Answer 25

• Involves massive systematic response (histamine)
• Leads to bronchoconstriction, shock, & death
• CMs:
  > hypotension
  > tachycardia
  > dyspnea
  > edema
  > hives
  > itching
  > resp or cardiac arrest

Question 26

Allergic Reactions: Nursing Interventions

Answer 26

1. Stop administration immediately
2. Apply oxygen (if needed)
3. Call rapid response team if severe
4. Notify PCP
5. Admin IV fluids as ordered
6. Admin antihistamines as ordered

Question 27

Pharmacokinetics

Answer 27

What the body does to the drug

Question 28

Agonist (Receptor Theory Type)

Answer 28

• Drugs interact directly w/ receptor sites
• Cause same activity of natural chemicals would case at tht site
• EX: insulin; beta-agonist

Question 29

Cholinergic Agonist

Answer 29

• Parasympathetic branch
• Mimics acetylcholine
• Incrs saliva production
• Slows HR
• Constricts bronchioles
• Stims digestive process
• Incrs urination
• Common use: Alzheimer’s disease

Question 30

Cholinergic Mnemonic - SLUDGE

Answer 30

S = salivation
L = lacrimation
U = urination
D = diaphoresis (sweating)
G = GI upset
E = emesis (vomiting)

Question 31

Adrenergic Agonist

Answer 31

• Sympathetic branch
• Tachycardia & vasoconstriction
• Bronchodilation
• Dcrd GI motility
• Glycogenolysis (incrd bld glucose)
• Constricts bladder sphincter
• Uses: cardiac & respiratory
• Sympathomimetic
  (think of switching the fight or flight ON)