Brainscape's Knowledge GenomeTM

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


See full index

Pharmacology > Kinetics And Dynamics > Flashcards

Kinetics And Dynamics Flashcards

1
Q

Pharmacokinetics

A

The study of the basic processes that determine the duration and intensity of the drug’s affect

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

To have the desired effect, a drug must

A

Reach its target

Be of sufficient concentration

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

Active transport

A

Requires energy to move a substance from an area of low concentration to an area of high concentration

  • mitochondria produce ATP
  • ATP -> ADP for biochemical energy
  • energy facilitates movement of ions up the concentration gradient
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Passive transport

A

Movement of a substance without the use of energy from an area of high concentration to an area of low concentration

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

Diffusion

A

Substances move until equilibrium is achieved
Passive diffusion - move from high to low concentration
Facilitated diffusion - move via carrier proteins from high concentration to low concentration

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

Osmosis

A

Movement of water from an area of low solute concentration to an area of high solute concentration (e.g., water follows salt)

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

Filtration (in osmosis)

A

Hydrostatic pressure that forces water or dissolved particles through a semipermeable membrane

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

Processes included in pharmacokinetics

A

Absorption, distribution, biotransformation (metabolism), elimination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Drug absorption

A

Process of movement of a drug from the site of application into the body and specific target

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Factors effecting rate of drug absorption

A
  • drug solubility
  • drug concentration
  • drug pH (acid/base)
  • site of absorption
  • circulatory status (force and volume of blood flow)
  • bioavailability (amount of medication in systemic circulation)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Drug solubility

A

The tendency of a drug to dissolve
“like dissolves like” (e.g., fat soluble penetrate fat containing cells)
- human body is 60% water
- Drugs given in water solutions are dissolved more quickly that’s those in oil-based, suspensions, or solid forms
- May be beneficial to have slower/faster absorption based on desired effect

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

Drug concentration

A

Drugs given in high concentrations are more quickly absorbed that those in low concentrations
- Drugs with various routes may have various concentrations (e.g., epi)

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

Drug pH

A

Acidic versus basic (alkaline)

  • Acidic drugs absorbed more readily in acidic environments (e.g. stomach)
  • Basic drugs more rapidly absorbed in alkaline environments (e.g. kidneys)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Site of absorption

A

Absorption depends on whether the drugs have to pass through various membranes prior to entering general circulation

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

Blood supply to site of absorption

A

Different body tissues and organs have varied degrees of blood supply
- Pulmonary epithelium, sublingual, muscles = rapid absorption
- Fatty tissue (SC) = poor blood supply, slower
System blood flow will affect absorption (eg., hypothermia, shock, dehydration)

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

Bioavailability

A

The amount of drug that is still active after it reaches its target tissue
- Must be sufficient amount to produce desired effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Distribution

A

Process whereby a drug is transported from the site of absorption to the site of action. Factors:

  • cardiovascular function
  • regional blood flow
  • drug storage reservoirs
  • physiological barriers
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Cardiovascular function

A

When normal, drugs are distributed initially to highly perfused areas like the brain, heart, lungs, liver
- Then delivered to GI system, skin, muscles, fat

Impaired cardiovascular system:

  • slows drug distribution
  • has unpredictable drug distribution
  • decreased drug delivery with poor perfusion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Regional blood flow

A

Many drugs travel through the body by binding to circulating proteins (eg., hemoglobin)
- depending on ability to bind, some portion of the drug will not be free to exert its pharmacological effect
Affected by:
- cardiogenic shock
- compromised cerebral circulation, etc.

20
Q

Bound drug (distribution)

A

When the drug binds with the receptor protein or becomes stored in the body’s fatty tissues

21
Q

Unbound drug (distribution)

A

When the drug is available to target tissues

22
Q

What are the most common circulating proteins that drugs bind to?

A

Albumin, followed by hemoglobin and globulin

23
Q

Blood-brain barrier or blood-cerebrospinal barrier

A

Tightly packed cell membranes restrict damaging drugs and toxins
- Prevents most drugs from passing directly into brain

24
Q

What does the blood-brain barrier consist of?

A

-Network of capillary endothelial cells that have no pores
- Surrounded by glial connective tissue
- Impermeable to water soluble drugs
Act as an effective barrier between the CNS and PNS

25
Q

Placental barrier

A

Protects from some substances passing from the mother into fetal circulation
To cross, the drug must be:
- lipid soluble
- non-protein bound

26
Q

Biotransformation

A

Metabolization of a drug into different chemicals called metabolites
- makes drug into a more/less active metabolite that is water soluble for elimination

27
Q

What is biotransformation dependent upon?

A
  • Chemical composition
  • Protein binding capacity
  • Metabolizing system function (eg., liver)
28
Q

What happens with decreased biotransformation

A

Metabolization is slowed, cumulative drug effects may occur

29
Q

What happens with increased biotransformation

A

Metabolism of drugs happening quickly. Dosing rates may need to be increased to maintain concentration

  • Tolerance. Same reason addicts increase “dose” as body more effectively metabolizes the drug
30
Q

Biotransformation inhibition

A

Drugs inhibiting the metabolism of other drugs (eg., alcohol and acetaminophen)

31
Q

Elimination

A

Movement of a drug or its metabolites from:
- Tissues back into circulation
- Circulation to the organs of excretion
Changes in normal rates of elimination may result in accumulation of drug in the body

32
Q

Drug half-life

A

Time required for the total amount of a drug in the body to dismiss by half

  • Tells us how long a drug will stay in the body
  • Most drugs eliminated after 5 half-lives
33
Q

Pharmacodynamics

A

What a drug will do to the body
- How a drug will work is based on it reaching its target cells
- Receptors on target cells is where drug enter the cells to cause a reaction
Drug and receptors bind to initiate a response
Receptors are “locks” and drugs are “key”

34
Q

Predictable responses

A

Anticipation of a response beyond the desired effect

  • side effects (adverse reactions)
  • risk-benefit ratio
35
Q

Factors effecting drug responses

A
  • Age
  • Weight
  • Gender
  • Environment
  • Time of administration
  • Condition of the patient
  • Genetic factors
36
Q

Four phases of drug action

A
  1. Administration phase- drug enters body
  2. Pharmaceutical phase- drug is broken down
  3. Pharmacokinetics phase- body alters the drug
  4. Pharmacodynamics phase- drug affects the body
37
Q

Therapeutic index

A

The minimum drug amount necessary for an ideal or desired response in the body

  • excess could be toxic/fatal
  • dosage determined by reaching ideal effects from drug
  • guidelines established for minimum concentrations to reach desire effects
38
Q

Iatrogenic responses

A

An adverse condition inadvertently induced in a patient by the treatment given (eg. Allergy, infection)

39
Q

Minimum concentration

A

The concentration of a drug needed to become effective

40
Q

Receptor theory (mechanism of action)

A

Majority of drugs act by binding to the protein molecules on the surfaces of cells
- stimulate or inhibit

Affected by:

  • Affinity
  • Efficacy
41
Q

Affinity

A

Force of attraction between a drug and receptor

- different meds may bind to same receptor site but bonds may vary

42
Q

Efficacy

A

A drug’s ability to cause the expected response
Mediated by:
- number of receptors
- ability of the drug molecule to activate the receptor

43
Q

Therapeutic threshold

A

The minimum concentration necessary for a drug to produce its desired effect.

  • some drugs have very narrow therapeutic indices
  • below therapeutic threshold = no desired response/undesired response
  • above therapeutic threshold = harmful/toxic effects
44
Q

Drug storage resevoirs

A

Tend to delay the medications onset of action and prolongs its duration of effect
- depends on if drug is bound or unbound
Tissue reservoirs include fat, bone, muscle

45
Q

Physiological barriers

A

A protective mechanism for drug distribution. Includes:

  • blood-brain barrier
  • placenta barrier
46
Q

What is the blood-brain barrier ineffective against?

A
  • oxygen
  • carbon dioxide
  • fat soluble molecules (anaesthetics, nicotine, entenox, ALCOHOL)
47
Q

What can cross the placenta barrier?

A

Materials that are:

  • lipid soluble
  • non-protein bound

Pharmacology (6 decks)

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