Brainscape's Knowledge GenomeTM

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


See full index

Fundementals > Pharmacology > Flashcards

Pharmacology Flashcards

1
Q

Pharmacokinetics is

A

the movement of a drug within the body. It includes the study of ADME.

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

ADME = ?

A 
A = Absorption - getting thru membranes to circulation
D = Distribution - movement of a drug from general circulation into the tissue spaces
M = Metabolism/Biotransformation - making the drug more suitable for elimination. Sometimes deactivates the drug.
E = Elimination removal of a drug/metabolites from the body.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Pharmacodynamics is

A

what the drug does to the body.
Dose/Response relationships
Drug-Receptor interactions: agonist, antagonist, inert binding

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

When does the “clock” on a patent start running on a drug patent? How long does it last?

A

Starts running at the time of Investigational New Drug IND application submission.
A patent lasts for 20 years.

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

What is an orphan drug?

A

Drugs developed for diseases with low incidence in the U.S.

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

What is a Pregnancy Category A?

A

A - Adequate, well controlled studies with pregnant woman have not demonstrated a risk to the fetus in the first trimester and no evidence of risk in later trimesters.

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

What is a Pregnancy Category B?

A

B - Animal studies no risk to the fetus.
No studies on pregnant women.
OR Animal studies - adverse effect, but adequate well-controlled studies on pregnant women have not demonstrated a risk to the fetus.

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

What is a Pregnancy Category C?

A

Animal study - adverse effect
No adequate well-controlled human studies
Benefit to Mother acceptable despite potential risks.
OR - No animal or human study.

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

What is a Pregnancy Category D?

A

Evidence of human fetal risk through adequate well-controlled observational studies. BUT benefit outweighs potential risk.

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

What is a Pregnancy Category X?

A

Good Studies show Fatal abnormalities. DO NOT USE DRUG ON PREGNANT WOMEN.

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

Schedule I drugs

A

High abuse potential. No use other than research. Ex. Heroin, LSD, Marijuana

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

Schedule II drugs

A

High Abuse Potential associated with severe dependence. (Psychologic and Physiologic) Ex. narcotics, amphetamines, barbiturates

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

Schedule III drugs

A

Less abuse potential with moderate dependence liability. Non-barbituate sedatives, anti-anxiety agents, and non-amphetamines stimulants, and narcotics in combo. ex. codeine/acetametaphine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Schedule IV

A

Less Abuse Potential with limited dependence. Some sedatives, anti-anxiety , non-narcotic analgesics. ex. Valium

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

Schedule V

A

Limited abuse potential. products with sm amts of narcotics (codeine) antitussives, anti-diarreals. Purchased from pharm w/o prescript. Nearly OTC.

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

What is a Gap Junction?

A

Protein that permits substances to pass btwn the cells w/o entering the ECF. (cytoplasmic tunnel.

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

Digoxin - mechanism and result

A

Competes with the K+ ions on the Na+/K+ ATPase pump. Increases the force of contraction.

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

Penicillin and Probenecid

A

Competitive antagonists for excretion carrier sites. Probenecid allows penicillin to have a greater 1/2 life. Probenecid occupies kidney excretion proteins before the penicillin b/c of its increase affinity for that protein binding site. Carrier Mediated Drug Transport.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Passive Diffusion

A

Lipid solubility and Fick’s Law

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Facilitated Diffusion

A

Carrier Dependent - saturation dependent, requires No energy but an electrochemical potential.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Paracellular pathway

A

Movement through intercellular channels - gaps btwn cells. Key pathway for drug passage. Principle driving force is hydrostatic pressure. Also onconic pressure, and drug concentration.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the principle transmembrane process for lipid soluble drugs?

A

Passive (simple) Diffusion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

The Rate of Diffusion depends on? (Fick’s Law)

A

(Concentration gradient x SA x Diffusion Coef)/Membrane Thickness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Most Drugs exist as weak electrolytes:

What does that mean? Why?

A

Weak acid: RH = (R-) +(H+)
Weak Base: RH + H+ = RH2+

This allows molecules to transverse through different layers of a membrane both hydrophobic and hydrophilic.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What does a pKa of 4.5 mean?

A

It means that at a pH of 4.5 the molecule will dissociate into 50% ionized and 50% non-ionized. pKa is a constant specific to each drug.

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

Ionized molecules pass through

A

Water

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

Non-ionized molecules pass through

A

lipids

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

A weakly acidic drug will accumulate on the acid or base side of the membrane?

A

On the basic side. A weakly basic drug will accumulate on the acidic side.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Le Chatlier’s Principle

A

Changes in a system that was once in equilibrium will tend to move toward re-establishing the equilibrium.

30
Q

Name the pH of
blood
CSF
Breast Milk

A

Blood = 7.4
CSF = 7.35
Breast Milk = ~6.8
pH differences are only significant for passive diffusion. Important in distribution through protected tissue.
=> a weak acid would accumulate in the blood.
=> a weak base would accumulate in the CSF and/or breast milk

31
Q

Name the Restricted Tissue Spaces:

A

Blood-Retinal Barrier, Testis, Blood-Brain Barrier, Breast, Placental Barrier

32
Q

What determines the rate of Drug distribution after drug absorption?

A 
Cardiac Output
Regional Blood Flow
Capillary Permeability
Tissue Volume
Drug lipid solubility (small limitation)
33
Q

First Phase and second phase - what tissues receive the greatest drug distribution?

A

1) liver, kidney, brain (restricted), lungs
2) Muscle, most viscera, skin and fat. (slower)

Usually drugs distribute rapidly because of the highly permeable membrane of the capillary endothelial membrane.

34
Q

Drug-Protein binding. What is it?

What proteins are involved?

A 
The binding of the drug to a protein:
Albumin
Lipoproteins
Erythrocytes
Alpha1-Acid Glycoprotein

The bound portion of a drug is not available for pharmacological response.
Can’t get through membranes by any mechanism.
Can’t be filtered in the Glomerulus
Can’t pass into hepatocytes

35
Q 
Perfusion Rates (%CO) of 
Kidney
Brain 
Liver
Muscle
Placenta
A 
Kidney = 20
Brain = 12
Liver = 24
Muscle = 23
Placenta = 10
36
Q

Apparent Volume of Distribution

A

Not a physical measurement!

Calculation of the volume needed to contain the amount of drug homogeneously distributed in the body at the concentration of the blood, plasma or water.

The volume in which an administered drug is distributed. In equilibrium the sampling of drug from one compartment should equal the drug concentration in all other compartments.

37
Q

The typical compartments considered when describing drug distribution

A

plasma fluid, interstitial fluid, intracellular fluid.

38
Q

Albumin:
Where is it synthesized?
What is it’s T1/2
Significance?

A

Liver
17 to 18 days
Maintains osmotic pressure of the blood.
MOST SIGNIFICANT PROTEIN FOR BINDING WEAK ACIDS.

39
Q

Alpha1-Acid Glycoprotein Importance?

A

Most important protein involved in the binding of drugs that are weak bases.

40
Q

Causes of Hypoalbuminemia

A

Hospitalization - Protein-Calorie Malnutrition. Decreased albumin when healing.
Absorption Deficiencies: poor absorption of dietary protein
Chronic Liver Disease (Cirrhosis)
Nephrotic Syndrome

41
Q

Nephrotic Syndrome =

A

Hyperlipidemia, Edema (hypovolemia) and Hypoalbuminemia

42
Q

Problems with Route Administration/Saturation of proteins binding sites

A

Rapid IV: Doesn’t bind fast therefore there is too much active drug unbound to protein.
IM: Exposure to other proteins: Cause a Drug Reservoir

43
Q

Drug reservoir

A

tissue proteins bind the drug. This can result in toxicity or prolonged drug action.
ex. Tetrocyclines in pregnant women and children - accumulates in teeth and bones.

44
Q

Major Organs involved in drug clearance:

A

Liver, Kidney Lesser: Sweat, Lungs, GIT (Bacteria that act like liver) Breast Milk

45
Q

Two mechanisms for drug clearance

A

Excretion and Metabolism (biotransformation)

Biotransformation is an enzymatic process that begins in the GIT.

46
Q

Two types of biotransformation reactions

A

From Lipophilic to Hydrophilic to Increase lipid solubility:
Phase I: Oxidation/Reduction - usually make it inactive. Although sometimes it results in active intermediate formation.
Phase II: Synthetic Reactions that enhance polarity and decrease lipid solubility (Makes it more water soluble)

47
Q

What are Prodrugs?

A

They require biotransformation in order to become an active metabolite that can elicit a pharmacological response.

The are designed to be inactive until metabolized to an active form.

48
Q

How can biotransformation affect distribution of a drug?

A

Increased polarity will limit movement through a plasma membrane, enhance renal excretion by reducing passive reabsorption.
Also will usually inactivate or decrease the pharmacologic activity of the drug

49
Q

What is the half life of a drug? What can affect the half life?

A

The half-life of a substance, usually denoted by t1/2, is the time taken for half of the dose to be eliminated or metabolized. A change in the biotransformation can change the half life. Things the change the rate of biotransformation Age, Nutrition, Disease, DDI. If the change is due to another drug it is a drug-drug interaction.
Liver disease increases half-life.

50
Q

What is an Enzyme Dependent Biotransformation?

A

Functions to unmask or introduce a functional group commonly making the drug more polar although it is sometimes, modified or enhanced.

51
Q

What is the enzyme that is responsible for the hepatic metabolism of over 50% of all clinically prescribed drugs?

A

CYP3A4
with CYP2D6 and you will cover 80% of all drugs.
Isoforms of P450

52
Q

What is the rate limiting step of biotransformation?

A

Phase II requires substrates to alter the drug metabolite. if the substrate is unavailable then the drug will accumulate and increase the t1/2. If phase II occurs w/o Phase I a toxic metabolite can be created instead of an easily excretable metabolite.

53
Q

What substrates are required for acetaminophen to be metabolized in phase II?
In phase I?
What is the toxic metabolite called?

A

Phase II: Glucoronide or Sulfate(these are polar and water soluble)
Phase I: Glutathione
NAPQI

54
Q

What drugs do elderly patients have a difficult time absorbing do to their decreased capacity?

A

Benzodiazepines, beta blockers, TCA (tricyclic antidepressants), barbituates

55
Q

What happens when chloramphenicol is not adequately metabolized?

A

It is a broad spectrum antibiotic. It can cause Grey-baby syndrome.

56
Q

Enzyme Induction is…

Problems that can occur are?

A

an enzyme that increases the metabolism of the inducing drug. It can produce an apparent drug tolerance, with drug-drug interaction-toxicity can result with the discontinuation of the inducing drug if the dose had been adjusted to the drug being metabolized.
Can involve new enzyme synthesis.

57
Q

What is an enzyme inducer? What are some examples?

A

An enzyme inducer is a type of drug that increases the metabolic activity of an enzyme either by binding to the enzyme and activating it. Barbituates and Phenytoin,(accelerate the metabolism of coumadin) Tobacco smoke, St. John’s Wort.

58
Q

How does enzyme inhibition occur? Examples.

A

Some drugs inhibit the enzyme inducers. these drugs form complexes with cytochrome P450. Results in toxicity &/or increased t1/2.
Examples: Grapefruit, Disulfiram(Antabuse), Erythromycin & Terfenadine => Torsades de pointes. TSA, SSRI’s, Ioniazid

59
Q

How does intestinal microflora affect drug metabolism?

A

Anaerobic microorganisms are rich in reductases. They can hydrolyze and neutralize glucuronide conjugates and if it is lipid soluble it can get reabsorbed into the intestines. Birth Control needs to be reabsorbed to work for a full cycle. ABX can mess that up.

60
Q

What is the principle mechanism for excreting a drug?

A

Renal excretion via Glomerular filtration

61
Q

Glomerular filtration of a drug is dependent on? What is the driving force?

A

Size and shape but not charge.
Arteriole pressure within the glomerular capillaries both afferent and efferent. Vasodilation and constriction are very significant in drug excretion.

62
Q

Why would you try to alkalinize urine output via bicarb?

A

If there is a weak-acid drug/toxin that you would like to remove from the system it will more likely stay in the renal tubules if it is a more basic environment.

63
Q

Biliary excretion occurs when…

Why would a drug get reabsorbed in the gut?

A

the drug has already been metabolized.

If a bacteria had hydrolyzed the conjugate, it could get reabsorbed. Ex. digoxin, chloramphenicol, cardiac glycosides.

64
Q

What is Bioavailability?

A

Fraction of the administered dose that reaches general circulation in unchanged form. %age of total dose administered as compared to IV administration.

65
Q

What is Bioequivalence?

A

An FDA way to compare Generics to trade names. All though something may have bioequivalence there still may be clinical differences, not to mention $ differences.

66
Q

What is the Therapeutic window?

A

It is the dose of a drug that keeps it above the Minimum Effective Concentration for the desired response and below the MEC for the Adverse Drug Reaction. Continuous Drug Dosing is designed to keep the drug level in the therapeutic range.

67
Q

What is the EC50 in a Maximal Effect vs potency graph?

A

Effective Concentration in 50% of the population. It is a good way to compare drugs on the basis of relative potency. Graphed to the left is more potent. Lower angle less effective with each increase in potency.

68
Q

TI = LD50/ED50 what does this mean?

A

Theurapeutic Index = Dose needed to kill 50% of popn/ the dose needed to be effective in 50% of patients.

69
Q

TI = TD50/ED50

A

Theurapeutic Index = toxic dose in 50% of people/effective dose in 50% of people.
this can have many meanings. Toxic could have many meanings…head ache to stomach ache etc.. Therefore there can be more than 1 TI per drug. The bigger the TI the better.

70
Q

In regards to Drugs

1) Full agonist =
2) Partial agonist =

A

1) A full agonist elicits a maximum response from an organ or tissue when all receptors of the tissue or organ are occupied.
2) A partial agonist in the same situation elicits a partial response.

71
Q

Antagonist is

A

a drug that binds to the same receptor as an agonist (drug or endogenous substance) but does not activate the receptor. Reversible or Irreversible

72
Q

If an antagonist is reversible what does that mean for the agonist?

A

At a higher dose the agonist can overcome the effects of the antagonist.

Fundementals (6 decks)

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