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Flashcards in Pharmacokinetics, Pharmacodynamics Deck (98)
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1
Q

RATE and EXTENT of DRUG ABSORPTION from dosage form

A

Bioavailability

2
Q

RATE and RELATIVE AMOUNT at which intact form of drug appears systemic circulation

A

Bioavailability

3
Q

study of rate processes and their relationship to responses in humans and animals

A

Pharmacokinetics

4
Q

Rate processes

A

Absorption
Distribution
Metabolism
Excretion

5
Q

Changes in concentration of drug in body

A

Pharmacokinetics

6
Q

What the body does to drug

A

Pharmacokinetics

7
Q

Relationship between drug concentration at site of action and pharmacologic response

A

Pharmacodynamics

8
Q

What the drug does to the body

A

Pharmacodynamics

9
Q

Entry of drug into systemic circulation

A

Absorption

10
Q

Form of administration with no absorption
Form of administration with 100% bioavailability
No loss of drug

A

IV

11
Q

Bioavailability formula

A

(AUC ORAL/AUC INJECTED) x 100

12
Q

Most to least available forms of administration

A

IV > IM > Subcutaneous > Oral

13
Q

Acidic drugs are best absorbed in

A

the stomach

14
Q

Basic drugs and stomach acid:

A

rapidly solubilized

15
Q

most important site for drug absorption

A

small intestine

16
Q

Slowly absorbed drugs are absorbed in the

A

large instestine

17
Q

rate at which the drug solution leaves the stomach and enters duodenum

A

Gastric Emptying Rate

18
Q

Decrease in Gastric Emptying rate

A

Decrease in rate of absorption (drug possibly degraded)

Decrease in onset of action or therapy (drug stays in stomach too long)

19
Q

Factors affecting Gastric Emptying (5)

A
1 Volume
2 Temperature
3 Body position
4 Drug property
5 Patient factors (disease, hunger, anxiety)
20
Q

Volume of ingested increased material affects GER

A

Initially an increase in GER -> decrease

21
Q

Bulky materials vs liquid…

A

Empty more slowly

22
Q

Fatty meal: GER

A

decreases

23
Q

Carbohydrate-rich meal: GER

A

decreased

24
Q

Hot temperature-meal: GER

A

increased

25
Q

Lying on the left: GER

A

decreased

26
Q

lying on the right: GER

A

increased

27
Q

lying down vs standing: GER

A

decreased

28
Q

Anticholinergics: GER

A

decreased

29
Q

Narcotics: GER

A

decreased

30
Q

Analgesics: GER

A

decreased

31
Q

Antidepressants: GER

A

decreased

32
Q

Antiemetics: GER

A

INCREASED

33
Q

Disease states that DECREASE GER (3)

A

Gastric ulcer
DM
Hypothyroidism

34
Q

Physiologic conditions that promote INC GER (3)

A

1 Hunger
2 Anxiety
3 Stress

35
Q

First Pass Effect

A

drugs are absorbed in the portal circulation and distributed to liver for metabolism

36
Q

When drugs undergo rapid first pass effect, what happens to bioavailability

A

Decreased

37
Q

route of first pass

A

oral/rectal -> lumen of GI -> portal circu -> liver

38
Q

DRUGS UNDERGOING SIGNIFICANT FIRST PASS (9)

A

ILMMNPPPS

1 Isoproterenol -nonselective B agonist isopropylamine analog of epinephrine
2 Lidocaine -blockade of voltage gated Na ch reversible AP prop
3 Meperidine - opiod morphine like on mu receror
4 Morphine
5 Nitroglycerine
6 Pentazocine - opiod agonist at kappa and blocker of mu receptor
7 Propoxyphene - full opiod agonist
9 Propranolol
10 Salicylamide - aspirine-like

39
Q

REVERSIBLE transfer of drug from one compartment to another

A

Distribution

40
Q

Distribution is affected by (2)

A

Rate of BLOOD FLOW into the tissue

PROTEIN binding

41
Q

Drugs bound to albumin (2)

A

1) canNOT cross biomembranes (bec too large)

2) NOT excreted

42
Q

Displacement of drug from albumin may

A

Enhance effect of displaced drug

43
Q

Acidic drugs are bound to

A

Albumin

44
Q

Basic drugs eg Propranolol are bound to

A

Alpha 1 glycoprotein

45
Q

When albumin is saturated, drugs bind to

A

Lipoproteins

46
Q

Hypothetical volume of BODY FLUID in which drug is dissolved

A

Volume of distribution

47
Q

Volume of distribution formula:

A

Dose of drug/ Drug in plasma

48
Q

When the drug is distributed EXTRAvascularly, the VD is

A

increased

49
Q

When more drug is in VASCULAR SPACE/PLASMA, VD is

bec?

A

decreased

protein bound (albumin)

50
Q

conversion of drug to EXCRETABLE form

A

Metabolism

51
Q

METABOLIC conversion of drugs

A

Biotransformation

52
Q

Phase 2 reactions:

A

Convert parent drug to a polar (water-soluble) form

53
Q

How are drugs converted to polar form?

A

Unmasking or insert functional groups luke OH SH NH

54
Q

Phase 1 reactions (4)

A

1 Oxidation CYP450, MFO
2 Reduction
3 Deamination
4 Hydrolysis

55
Q

Phase 2 reactions are synthetic reactions wherein there is

A

Conjugation of drugs bound to OH SH NH (1st phase) into (6)

Glucoronate
Acetate
Glutathione
Glycine
Sulfate
Methyl groups
56
Q

Drugs that underwent phase 2 reaction are more

A

Polar and less lipid soluble

57
Q

Most important site of drug metabolism

A

Liver

58
Q

Minor role in drug metabolism

A

Kidneys

Heart, Intestine, Skin

59
Q

Enzyme inducers (7)

PCRABS

A

1 Phenobarbital - inc amount of time Cl channels are open on GABA-A receptor units

2 Phenytoin - block of voltage-dependent Na channels and AP

3 Rifampicin - inhibits bacterial DNA dependent RNA polymerase of B subunit

4 Carbamazepine - blocks voltage-gated Na channels in their inactive conformation preventing AP

5 Barbecued food / Cigarette

6 Chronic alcoholism

7 St John’s Wort/Hypericum perforatum- for depression;inhibits serotonin, dopamine, norepinephrine in synaptic cleft binding GABA-A and GABA-B receptors and increasing serotonin receptors
Inhibits MAO and COMT enzyme allowing more dopamine to be converted to norepinehrine

  1. Griseofulvin
  2. Modafinil
  3. Cyclophosphamide
60
Q

Enzyme inhibitors (9)

G PACMAN

A
Metronidazole
Erythromycin (Macrolide except Azithromycin)
Disulfiram
INH
Cimetidine
Ketoconazole
Valproic acid
Acute alcoholism
Grapefruit juice
Protease inhibitors
Amiodarone
Ritonavir
61
Q

constant AMOUNT per unit time is metabolized

A

ZERO ORDER KINETICS

62
Q

rate does NOT increase even if drug concentration increases

A

Zero Order Kinetics

Aspirin

63
Q

Non linear on semilog paper

Horizontal straight line

A

Zero order kinetics

64
Q

Rate or amount eliminated any time is constant

A

Zero Order Kinetics

65
Q

constant FRACTION per unit time metabolized

A

First Order Kinetics

66
Q

Rate INCREASES as drug concentration INCREASES

A

First Order Kinetics

67
Q

Linear relationship of concentration and time on semilog paper

A

First Order Kinetic

68
Q

Rate or amount of chemical elimination is PROPORTIONAL to the concentration or amount

A

First Order Kinetics

69
Q

Half life is INdependent of dose

A

First Order Kinetics

70
Q

True halflife or elimination constant does NOT exist

A

Zero Order Kinetics

71
Q

Concentration of chemical in plasma decreases by constant fraction per unit time

A

First Order Kinetics

72
Q

Saturable Kinetics

A

Zero Order Kinetics

73
Q

Michaelis Menten Kinetics

A

Zero Order Kinetics

74
Q

Capacity-Limited Kinetics

A

Zero Order Kinetics

75
Q

removal of drug in a system

A

Excretion

76
Q

Clearance

A

is Volume of Drug cleared of the drug in unit time

77
Q

Major route of drug elimination for polar molecules

A

Renal

78
Q

Major route of drug elimination for water soluble drugs

A

Renal

79
Q

Major route of elimination for drugs with low molecular weight <500

A

Renal

80
Q

Major route of elimination for drugs that are biotransformed slowly

A

Renal

81
Q

Excretion (3)

A

Glomerular filtration
Tubular reabsorption
Active tubular secretion

82
Q

PASSIVE process where small molecules are filtered through glomerulus and nephron

A

Glomerular filtration

83
Q

drugs bound to albumin are

A

not excreted

84
Q

GFR excretes

A

creatinine

decrease in clearance indicates kidney problem

85
Q

CARRIER MEDIATED

A

active tubular secretion

86
Q

Volume of PLASMA CONTAINING DRUG that is cleared by liver per unit time

A

Hepatic clearance

87
Q

Competes with active tubular secretion of penicillin

A

Probenecid - blocks pannexin channel URAT1 (uric acid reabsorption) and OAT organic acid transport pump inhibiting organic anion secretion into tubule where penicillin is secreted in exchange for dicarboxylate anion

Increased Penicilloic acid (metabolite)

increases concentration of Penicillin

88
Q

Excretory pathway for drugs >500 MW

A

Biliary

89
Q

Excretion pathway for anticancer drugs (2)

A

Mammary

Genital

90
Q

Excretion pathway for metals, alcohols

A

Sweat

91
Q

Doxycycline excreted via

A

Intestine

92
Q

Volume of PLASMA ELIMINATED OF DRUG per unit time

A

Drug Clearance

93
Q

Clearance formula

A

Elimination rate/Plasma concentration

94
Q

Maintenance Dose

A

Dosing Rate x Dosing Interval

95
Q

PASSIVE process

Lipid soluble, non ionized drugs reabsorbed

A

Tubular Reabsorption

96
Q

Tubular reabsorption is affected by

A

pH urine

97
Q

G6PD results in (2)

A

Dec NADPH

Dec Glutathione

98
Q

Hemolysis occurs in G6PD

A

Bec of lack of NADPH and glutathione that will protect RBCs once induced with oxidative stress like infection, drugs, fava beans