Pharmacokinetics, Pharmacodynamics Flashcards
(98 cards)
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
Lying on the left: GER
decreased
26
lying on the right: GER
increased
27
lying down vs standing: GER
decreased
28
Anticholinergics: GER
decreased
29
Narcotics: GER
decreased
30
Analgesics: GER
decreased
31
Antidepressants: GER
decreased
32
Antiemetics: GER
INCREASED
33
Disease states that DECREASE GER (3)
Gastric ulcer
DM
Hypothyroidism
34
Physiologic conditions that promote INC GER (3)
1 Hunger
2 Anxiety
3 Stress
35
First Pass Effect
drugs are absorbed in the portal circulation and distributed to liver for metabolism
36
When drugs undergo rapid first pass effect, what happens to bioavailability
Decreased
37
route of first pass
oral/rectal -> lumen of GI -> portal circu -> liver
38
DRUGS UNDERGOING SIGNIFICANT FIRST PASS (9)
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
REVERSIBLE transfer of drug from one compartment to another
Distribution
40
Distribution is affected by (2)
Rate of BLOOD FLOW into the tissue
| PROTEIN binding
41
Drugs bound to albumin (2)
1) canNOT cross biomembranes (bec too large)
| 2) NOT excreted
42
Displacement of drug from albumin may
Enhance effect of displaced drug
43
Acidic drugs are bound to
Albumin
44
Basic drugs eg Propranolol are bound to
Alpha 1 glycoprotein
45
When albumin is saturated, drugs bind to
Lipoproteins
46
Hypothetical volume of BODY FLUID in which drug is dissolved
Volume of distribution
47
Volume of distribution formula:
Dose of drug/ Drug in plasma
48
When the drug is distributed EXTRAvascularly, the VD is
increased
49
When more drug is in VASCULAR SPACE/PLASMA, VD is
bec?
decreased
protein bound (albumin)
50
conversion of drug to EXCRETABLE form
Metabolism
51
METABOLIC conversion of drugs
Biotransformation
52
Phase 2 reactions:
Convert parent drug to a polar (water-soluble) form
53
How are drugs converted to polar form?
Unmasking or insert functional groups luke OH SH NH
54
Phase 1 reactions (4)
1 Oxidation CYP450, MFO
2 Reduction
3 Deamination
4 Hydrolysis
55
Phase 2 reactions are synthetic reactions wherein there is
Conjugation of drugs bound to OH SH NH (1st phase) into (6)
```
Glucoronate
Acetate
Glutathione
Glycine
Sulfate
Methyl groups
```
56
Drugs that underwent phase 2 reaction are more
Polar and less lipid soluble
57
Most important site of drug metabolism
Liver
58
Minor role in drug metabolism
Kidneys
Heart, Intestine, Skin
59
Enzyme inducers (7)
PCRABS
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
8. Griseofulvin
9. Modafinil
10. Cyclophosphamide
60
Enzyme inhibitors (9)
G PACMAN
```
Metronidazole
Erythromycin (Macrolide except Azithromycin)
Disulfiram
INH
Cimetidine
Ketoconazole
Valproic acid
Acute alcoholism
Grapefruit juice
Protease inhibitors
Amiodarone
Ritonavir
```
61
constant AMOUNT per unit time is metabolized
ZERO ORDER KINETICS
62
rate does NOT increase even if drug concentration increases
Zero Order Kinetics
Aspirin
63
Non linear on semilog paper
| Horizontal straight line
Zero order kinetics
64
Rate or amount eliminated any time is constant
Zero Order Kinetics
65
constant FRACTION per unit time metabolized
First Order Kinetics
66
Rate INCREASES as drug concentration INCREASES
First Order Kinetics
67
Linear relationship of concentration and time on semilog paper
First Order Kinetic
68
Rate or amount of chemical elimination is PROPORTIONAL to the concentration or amount
First Order Kinetics
69
Half life is INdependent of dose
First Order Kinetics
70
True halflife or elimination constant does NOT exist
Zero Order Kinetics
71
Concentration of chemical in plasma decreases by constant fraction per unit time
First Order Kinetics
72
Saturable Kinetics
Zero Order Kinetics
73
Michaelis Menten Kinetics
Zero Order Kinetics
74
Capacity-Limited Kinetics
Zero Order Kinetics
75
removal of drug in a system
Excretion
76
Clearance
is Volume of Drug cleared of the drug in unit time
77
Major route of drug elimination for polar molecules
Renal
78
Major route of drug elimination for water soluble drugs
Renal
79
Major route of elimination for drugs with low molecular weight <500
Renal
80
Major route of elimination for drugs that are biotransformed slowly
Renal
81
Excretion (3)
Glomerular filtration
Tubular reabsorption
Active tubular secretion
82
PASSIVE process where small molecules are filtered through glomerulus and nephron
Glomerular filtration
83
drugs bound to albumin are
not excreted
84
GFR excretes
creatinine
decrease in clearance indicates kidney problem
85
CARRIER MEDIATED
active tubular secretion
86
Volume of PLASMA CONTAINING DRUG that is cleared by liver per unit time
Hepatic clearance
87
Competes with active tubular secretion of penicillin
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
Excretory pathway for drugs >500 MW
Biliary
89
Excretion pathway for anticancer drugs (2)
Mammary
| Genital
90
Excretion pathway for metals, alcohols
Sweat
91
Doxycycline excreted via
Intestine
92
Volume of PLASMA ELIMINATED OF DRUG per unit time
Drug Clearance
93
Clearance formula
Elimination rate/Plasma concentration
94
Maintenance Dose
Dosing Rate x Dosing Interval
95
PASSIVE process
| Lipid soluble, non ionized drugs reabsorbed
Tubular Reabsorption
96
Tubular reabsorption is affected by
pH urine
97
G6PD results in (2)
Dec NADPH
| Dec Glutathione
98
Hemolysis occurs in G6PD
Bec of lack of NADPH and glutathione that will protect RBCs once induced with oxidative stress like infection, drugs, fava beans
