Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Pharmacology > Pharmacokinetics > Flashcards

Pharmacokinetics Flashcards

1
Q

pharmacokinetics

A

study of how the body affects a drug over time

-what the body does to the drug

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

roles & responsibilities in prescribing

A

-take history
-perform physical
-formulate diagnosis
-develop tx plan that is person centered:
nonpharmacologic vs. pharmacologic`

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

pharmacodynamics

A

how the body reacts to the drug itself

-effect of the drug on the body cellularly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

pharmacotherapeutics

A

disease being treated by drug

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

non-pharmacologic treatment plan

A

first tx plan to consider, least invasive

  • dietary change
  • PT
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

pharmacologic treatment

A

medication that can be prescription or OTC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

methods to avoid medication error

A

asking if pt can read

asking what other meds pt is on

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

considerations for therapy

A 
previous treatments/allergies to medications
interactions- if pt is on herbal supplements and/or OTC meds
side effects
comorbidities
age
cost
if pt is pregnant
gender
weight
ease of use- pt's schedule, how often med must be taken
religious/cultural needs
nationality
living environment/support system
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

parameters of pharmacokinetics

A 
absorption
distribution
metabolism
excretion
half-life
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Absorption

A

what occurs after drug is administered at site: GI tract —–> blood plasma
-drug may or may not bind to protein
» free drug: effective
» bound drug: non-effective

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

relative drug contradiction

A

using drug with caution in setting of other diseases
ex) Tylenol and the liver
alcoholic pt cannot metabolize Tylenol in large amounts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

pharmacology of Metformin

A

kinetics: ingested orally into stomach & metabolized in liver and kidney
dynamics: stimulating the body to release insulin
therapeutics: treating type II DM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

characteristics of drug effect and relationship to therapeutic window

A
  1. onset of effect for PO meds = when absorption occurs -> will reach peak effect = equilibrium concentration in tissue is the same as plasma
  2. minimal effective concentration for desired response
  3. time period between onset and MEC = duration of action (therapeutic window)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

lag period

A

when medication is administered and prior to onset of effect of drug

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

true drug contraindication

A

true drug allergy

ex) allergic rxn to PCN

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

factors to consider in administration of drug

A
  • barriers that drug will need to pass through
  • setting that med will be administered
    ex) at home vs. inpatient
  • urgency of need for med
    ex) pt in the ER
  • stability of drug
  • first pass effect
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

first pass effect

A

when drug is metabolized in the liver, the drug loses some potency before it is dispersed in circulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

parenteral administration

A

routes of administration that DO NOT involve drug absorption via the GI tract

  • IV
  • IM
  • SQ
  • transdermal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

oral administration (PO)

A

most common route of administration that is absorbed via GI tract -> liver -> blood

  • variable absorption pattern that is affected by many factors
    advantage: most common, convenient, and economical
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

disadvantages of oral administration

A
  • limited absorption of some drugs
  • food may affect absorption
  • pt compliance is necessary
  • drugs may be metabolized before systemic absorption
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

intravenous administration (IV)

A

parenteral administration in which absorption is not required

  • occurs in hospital setting, valuable in emergent situations
  • can have immediate effects
  • ideal if dosed in large volumes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

advantages of IV administration

A

immediate effects

  • suitable for irritating substances and complex mixtures
  • valuable in emergencies
  • dosage titration permissible
  • ideal for high molecular weight proteins & peptide drugs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

disadvantages of IV administration

A

unsuitable for oily substances

  • bolus injection may result in adverse effects
  • most substances must be slowly injected
  • strict aseptic techniques needed
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Subcutaneous administration (SC or SQ)

A

parenteral administration injected in subq tissue in which absorption depends on drug diluents

  • aqueous solution: prompt
  • depot preparations: slow & sustained
    ex) insulin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

advantages of subcutaneous administration

A

suitable for slow release drugs

-ideal for some poorly soluble suspensions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

disadvantages of subcutaneous administration

A

pain or necrosis if drug is irritating

-unsuitable for drugs administered in large volumes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

intramuscular administration (IM)

A

parenteral administration injected into muscle in which absorption depends on drug diluents
-aqueous solution: prompt
-depot preparations: slow & sustained
ex) Toradol
preferable to IV if pt must self-administer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

advantages of intramuscular administration

A

suitable if drug volume is moderate

  • suitable for oily vehicles and certain irritating substances
  • preferable to IV if pt must self-administer
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

disadvantages of intramuscular administration

A

affects certain lab tests ( creatine kinase)

  • can be painful
  • can cause IM hemorrhage (precluded during AC therapy)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

transdermal administration

A

parenteral administration with patch in which absorption of drug is slow and sustained
ex) nicotine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

advantages of transdermal administration

A

bypasses first-pass effect

  • convenient & painless
  • ideal for drugs that are lipophilic and have poor oral bioavailability
  • ideal for drugs that are quickly eliminated by the body
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

disadvantages of transdermal administration

A

some pts are allergic to this which can cause rxn

  • drug must be highly lipophilic
  • may cause delayed delivery of drug to pharmacological site of action
  • limited to drugs that can be taken in small daily doses
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

rectal administration

A

administration in which absorption is erratic & variable

  • partially bypasses first-pass effect
  • ideal if drug causes vomiting
  • not a well accepted route
34
Q

advantages of rectal administration

A

partially bypasses first-pass effect

  • bypasses destruction by stomach acid
  • ideal if drug causes vomiting
  • ideal in pt that are vomiting or comatose
35
Q

disadvantages of rectal administration

A

drugs may irritate mucosa

-not a well accepted route

36
Q

inhalation

A

administration in which absorption is fast and may be systemic; not always desirable

  • ideal for gases
  • effective for pts with respiratory problems
  • dose can be titrated
  • localized effect to target lungs
  • lower doses used compared to oral or parenteral administration
  • fewer systemic side effects
37
Q

disadvantages of inhalation

A

most addictive route of administration as drug can enter brain quickly

  • pt may have difficulty regulating dose
  • pt may have difficulty of use
38
Q

sublingual

A

route of administration in which absorption depends on the drug

ex) NTG: rapid, systemic absorption
- most drugs erratically or incompletely absorbed

39
Q

advantages of sublingual administration

A

bypasses first-pass effect and destruction by stomach acid

  • drug stability maintained because the pH of saliva is relatively neutral
  • may cause immediate effects
40
Q

disadvantages of sublingual administration

A

limited to certain types of drugs

  • limited to drugs that can be taken in small doses
  • may lose part of the drug dose if swallowed
41
Q

most common routes of drug administration

A

IV
IM
SC/SQ

42
Q

oral tablets

A

entero-coated (protect stomach lining) that dissolves after passing through stomach

a. extended release: timed release that is once a day dosing (XL)
b. immediate release: absorbed into stomach and effective immediately

43
Q

oral vs. IV

A

oral drugs enter stomach first -> metabolize in liver -> portal circulation -> systemic circulation
» many opportunities to become ineffective
IV drugs enter directly into systemic circulation -> direct access to rest of body -> effective immediately

44
Q

subcutaneous injection

A

administered into tissue
flu shot
insulin

45
Q

intramuscular injection

A

administered into muscle which is deeper

ex> DEPO injection stays in muscle for longer time and gradually dissipate/released from muscle over time

46
Q

absorption

A

how drugs are absorbed from GI tract into cells
-influenced by:
> route of administration
> blood flow (places with more blood flow will access drug more easily)
> surface area available (optimal for meds to be absorbed in intestines rather than stomach)
> solubility (must be in lipid soluble state
> drug-drug interactions
> pH

47
Q

passive diffusion

A

most common pathway for how meds are absorbed

  • molecules move down concentration gradient from higher to lower concentration
    1. water soluble drug -> aqueous channel or pore
    2. lipid soluble drug - dissolved in membrane
  • no cellular energy expended/no carriers
  • stops when concentration is equal
48
Q

active transport

A

energy dependent absorption pathway where meds must use ATP to move across concentration gradient (lower to higher)

  • specific carrier proteins move drug molecules across gradient
  • can become saturated
  • may be competitively inhibited by other co-transported substances
49
Q

facilitated diffusion

A

carrier proteins allow drug molecules to piggy-back through membrane

  • can become saturated -> some drug will be lost
  • can be inhibited by competitive compounds as drugs may be similar to compounds in the body
50
Q

endocytosis

A

used for large molecules where membrane engulfs drug and pinches off in a drug filled vesicle

51
Q

fast absorption

A

IV
inhalation
sublingual

52
Q

slow absorption

A

oral
IM
subcutaneous

53
Q

increased blood flow

A

results in increased absorption of drug

54
Q

decreased surface area

A

results in decreased absorption of drug

ex) stomach vs. intestines

55
Q

distribution

A

process by which drug leaves bloodstream and enters the interstitium of tissues’ cells
> depends on drugs:
-ability to permeate capillaries
-vascularity of tissues
-ability to bind to plasma proteins (albumin)
-ability to bind to tissue protein via active transport
-fat or water soluble characteristic
-drug dissolution
-GI tract environment

56
Q

albumin

A

plasma protein in which FREE drug binds to during distribution of drug
ex) dilantin has affinity for this

57
Q

organs that drugs are distributed to quickly

A

due to more blood volume

  • heart
  • liver
  • kidneys
58
Q

organs that drugs are distributed to slower

A

due to les vascularity/lack of capillaries

  • skin
  • muscle
  • fat
59
Q

lipid soluble drugs

A

easily cross through cell membranes

-cross through blood brain barrier

60
Q

water soluble drugs

A

cannot pass easily through cell membranes

61
Q

blood brain barrier

A

diffusion barrier which impedes influx of most compounds from blood to _

  • do not allow ionized molecules to enter
  • allow non-ionized molecule not bound to plasma proteins because they are easily lipid soluble
62
Q

Primary sites of metabolism

A

Liver
Kidney
Biliary Tract

63
Q

cytochrome p450 system (CYPs)

A

Enzymes in liver responsible for most oxidative rxns of drugs
-metabolize most drugs and other lipophilic

64
Q

mechanism of CYPs

A

[drug] in bloodstream is lowered by first-pass effect and induction/inhibition of drug metabolism
Ex. hx of cirrhosis, hepatitis, their ability to metabolize drugs is reduced→ higher risk for toxicity and side effects due to lack of metabolism
EX Tylenol: people with a hx of liver disease→ reduce dosage of Tylenol from 4 to 2grams

65
Q

Factors that Impact Metabolism

A

food in stomach→ slows passing of drug through stomach
pre-existing conditions
other drugs (including alcohol)
Drug tolerance

66
Q

Excretion

A

removal of waste substances from body fluids by the kidney

67
Q

primary organ that eliminates drug via …

A

the kidney

  1. Glomerular filtration—free drug passes from blood into nephron via diffusion (high to low concen)—nonionized drugs pass more readily
  2. Tubular excretion by efferent arteriole into tubule via carrier /ATP
  3. Tubular reabsorption
68
Q

Clearance

A

rate of elimination of substances from the blood

69
Q

Renal clearance

A

total amount of drug excreted over time

70
Q

Drug elimination by the kidney

A

Free drug enters glomerulus(* only the free drug can enter nephron) → active secretion of drugs into proximal tubule→ passive reabsorption of lipid-soluble, unionized drug into blood→ ionized, lipid-insoluble drug passed into urine

71
Q

importance of urinary pH

A

increase pH to change solubility and ionization of compounds→ decrease amount of drug that is reabsorbed→ increase amount that is excreted

72
Q

creatinine clearance CrCl

A

Used to estimate renal function or GFR→ If kidney isn’t functioning properly, you will have more accumulation of the drug

73
Q

Creatinine

A

waste product that comes from skeletal muscle when creatine phosphate is broken down
ex) elderly pts with lower muscle mass -> level of creatinine is reduced due to lower creatine in muscle

74
Q

normal serum creatinine

A

sCr = 1 mg/dL

75
Q

Factors that influence CrCl

A

> Age
Gender : Female creatinine clearance is lower than male clearance
Weight (and height)—body weight
ex) if someone has a lot of water weight from edema, use height with calculation
Serum creatinine (sCr)

76
Q

dosing for patients with renal impairment

A

based on CrCl calculations from Cockcroft-Gault formula
* CrCl decreases = decrease in renal function→ lower strength of dosage or decrease frequency of drug
» the medication is not being excreted; staying in system longer so you don’t need to dose it as frequently

77
Q

Half-life (t ½)

A

time for the drug concentration to fall to ½ its original concentration
-Measure of how long it takes for 50% of a drug to be eliminated from bloodstream

78
Q

importance of half life

A 
helps determine:
Dose
Dosing intervals
Clearance
Time it takes to reach “steady state”—a therapeutic blood level—amount of drug being absorbed is the same amount being cleared—keeping pt inside therapeutic window
79
Q

6 half-life rule

A

it takes 6 half-lives for the concentration of a medication to reach a point where it stops causing any effects

  • how long a medication is in the body
  • useful for pain management dosing
    ex) IR vs. ER dosing
80
Q

extended release

A

dose in which medication will maintain therapeutic blood level

81
Q

importance of 6 half-life rule

A

determines frequency of dosing (to prevent toxicity)

  • indicates when you can begin a procedure (ie. if pt is on an anticoagulant, pt must d/c X amount of days prior to ensure it is out of their system)
  • useful for when you can start a different medication (to prevent drug-drug interactions)

Pharmacology (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions