Basic Concepts of Pharm Flashcards
0
Q
Pharmacokinetics or Pharmacodynamics?
Drug concentration in systemic circulation
A
Pharmacokinetics
1
Q
Pharmacokinetics or Pharmacodynamics?
Dose of Administered drug
A
Pharmacokinetics
2
Q
Pharmacokinetics or Pharmacodynamics?
Drug concentration at the site of action
A
Both
3
Q
Pharmacokinetics or Pharmacodynamics?
Drug in tissues and body compartments
A
Pharmacokinetics
4
Q
Pharmacokinetics or Pharmacodynamics?
Drug metabolized or excreted
A
Pharmacokinetics
5
Q
Pharmacokinetics or Pharmacodynamics?
Pharmacological effect
A
Pharmacodynamics
6
Q
Pharmacokinetics or Pharmacodynamics?
Clinical response
A
Pharmacodynamics
7
Q
Pharmacokinetics or Pharmacodynamics?
Toxicity
A
Pharmacodynamics
8
Q
Pharmacokinetics or Pharmacodynamics?
Effectiveness
A
Pharmacodynamics
9
Q
Pharmacokinetics or Pharmacodynamics?
What the drug does to the body
A
Pharmacodynamics
10
Q
Pharmacokinetics or Pharmacodynamics?
What the body does to the drug
A
Pharmacokinetics
11
Q
Interaction of drug with _ causes changes in the cell to produce drug’s effects
A
receptor
12
Q
What are the most common types of receptors?
A
- Membrane recptors
- Ligand gated ion channels
- Voltage gated ion channels
- Enzymes (esp. inhibitors)
13
Q
What type of receptor?
Beta adrenergic receptor
A
Membrane receptor
14
Q
What type of receptor?
GABA receptor
A
Ligand gated ion channel
15
Q
What type of receptor?
Na+ channel
A
Voltage gated ion channel
16
Q
What type of receptor?
Phosphodiesterase inhibitor
A
Enzyme
17
Q
Relationship of Ropivicaine to Bupivicaine
A
R enantiomer - demonstrates stereochemistry
18
Q
What is a racemic mixture?
A
2 enantiomers are present in equal proportion
19
Q
What feature of drugs is demonstrated in the intended and side effects of thaliamide?
A
Stereochemistry. Intended as an antiemetic, but has teratogenic effects. side note: Acidic hydrogen at chiral center makes purified separation to avoid teratogenicity futile
20
Q
What is a drug that produces its clinical effect by binding to a receptor and activating it (mimetic)?
A
agonist
21
Q
What is a drug that produces its clinical effect by binding to a receptor WITHOUT activating it and simultaneously prevents an agonist from stimulating it (blocking)?
A
antagonist
22
Q
What is a drug that combines directly with its receptor to trigger its physiologic response?
A
direct agonist
23
Q
Direct agonist or indirect agonist?
PHENYLEPHRINE
A
Direct
binds to alpha receptors in the peripheral vascular system can directly activates them to cause vasoconstriction
24
Direct agonist or indirect agonist?
| AMPHETAMINES and EPHEDRINE
Indirect
which evoke the RELEASE OF NOREPINEPHRINE from post synaptic nerve endings…..denervation or depletion of the neurotransmitter (after repeated doses, for example) will cause the administered drug to have less effect.
25
What is a drug that produces its physiologic response by increasing the concentration of ENDOGENOUS substrate (neurotransmitter or hormone) at receptor site?
indirect agonist
26
What is a drug that inhibits inactivation of neurotransmitter at terminal by preventing reuptake or inhibiting degradation metabolism?
indirect agonist
27
What is the following an example of?
Receptor inhibition which can be overcome by INCREASING the concentration of the agonist at the receptor site (reversible blockade)
Competitive antagonism
28
What is the following an example of?
| Receptor inhibition which CANNOT be overcome by increasing the concentration of the agonist (irreversible blockade)
Non-competitive antagonism
29
What type of drug is Naloxone (Narcan)?
Competitive Antagonist of opioid receptor
30
What is the mechanism of Neostigmine's use intraoperatively?
Used for reversal of non-depolarizing NMB agents.
Indirect cholinergic agonist, targets acetylcholinesterase and thereby increases acetylcholine, which can compete with non-depolarizing NMB agents (which are competitive antagonists of Acetylcholine receptors).
31
What type of receptors are muscarinic acetylcholine receptors?
Membrane receptors (G protein coupled receptors)
32
What type of receptors are nicotinic acetylcholine receptors?
Ligand gate ion channels
33
What are the enteral routes of administration?
PO (by mouth), rectal, sublingual
34
Which enteral routes of administration are not subject to first pass metabolism?
rectal and sublingual
35
List the parenteral routes of administration
IV, IM, SC, Pulmonary, intraaterial, intrathecal, nasal, Transdermal/Topical
36
Terminology:
| HYPERACTIVE
unusually low dose triggers pharmacological effect – very sensitive patients
37
Terminology:
| HYPERSENSTITIVE
allergic to drug
38
Terminology:
| HYPOREACTIVE
pt requires large dose for desired effect…often due to chronic exposure (tolerance)
39
Terminology: another word for tolerance
HYPOREACTIVE
40
Terminology:
| TACHYPHYLAXIS
decreased effectiveness of a drug with multiple doses (ex. Ephedrine)
41
Terminology:
| ADDITIVE
second drug administered with the first will produce an effect EQUAL to the sum of the 2 doses if administered independently
42
Terminology:
| SYNERGYSITIC
2 drugs administered together may produce a GREATER effect than either drug given alone
43
Terminology:
| ANTAGONISTIC
2 drugs administered together have LESSER effect than either given alone
44
Terminology:
| PRODRUG
Pharmacologically inactive compounds designed to maximize the amount of active species that reaches its site of action (ace inhibitors)
45
List the site specific factors affecting absorption
- Blood flow at site
- Surface area for absorption
- Solubility of drug at site
46
Components of the 2 compartment model
Central compartment
| Peripheral compartment
47
Features of the Central compartment
- rapid uptake of drug
- includes intravascular fluid and highly perfused tissues like the lungs, heart, brain, kidneys, and liver
- 75% of cardiac output, 10% of body mass
48
What organs comprise the vessel rich groups?
- lungs
- heart
- brain
- kidneys
- liver
49
From which compartment are drug usually eliminated?
central compartment
50
Features of the Peripheral compartment
- slower uptake
| - Includes less vascular tissues like fat, bone, and inactive skeletal muscle
51
What is the relationship between the volume of distribution and the elimination half life?
Greater the Vd, the longer the elimination half-life (excluding the effects of protein binding)
52
What does the volume of distribution tell about a drug?
- Volume of distribution is hypothetical.
| - Relates the amount of drug in the body to the concentration of drug in the blood or plasma
53
What does a small volume of distribution tell about a drug?
Small Vd indicates that majority of drug remains in plasma
54
What does a large volume of distribution tell about a drug?
Large Vd indicates that drug is extensively taken up by tissues.
55
What is the Distribution Phase?
– immediately after administration of drug
| – movement from central to peripheral compartments
56
What is the Elimination Phase?
– more gradual as drug is removed from circulation
| – Includes metabolism and excretion
57
List main proteins involved in protein binding and the types of drugs they bind
ALBUMIN binds acidic drugs
| ALPHA-1-ACID GLYCOPROTEINS bind basic drugs
58
Which protein are barbiturates more likely to bind?
Albumin
59
Which protein are local anesthetics more likely to bind?
alpha 1-acid glycoprotein (AAG)
60
What is the result of decreasing the concentration of proteins in the blood?
If these proteins are diminished or if the protein-binding sites are occupied (eg, other drugs), the amount of free drug available for tissue uptake is increased.
61
What is the relationship between protein binding of a drug and the volume of distribution?
Inverse, if highly protein bound, a drug remains in the blood and won’t move out to other compartments.
62
Give examples of highly protein bound drugs
WARFARIN
PROPRANOLOL
PHENYTOIN (DILANTIN)
63
What is the relationship between the degree of protein binding of a drug and it's clearance?
A drug bound to a protein also has POOR CLEARANCE
64
True or False:
| Protein bound drugs can cross cell membranes
False
65
True or False:
| Protein bound drugs are pharmacologically inert
False
As soon as unbound drug leaves circulation, the law of mass action dictates that some of the bound drug will dissociate from binding site restoring the free drug concentration
66
When pK and pH are IDENTICAL, how much of the drug exists in the ionized and non ionized forms?
50% of the drug exists in both the IONIZED and NONIONIZED form
67
True or False
| Ionized drugs have difficulty crossing the cell membrane
True
68
What determines the ionization of a drug?
- it's pKa
| - the pH of the surrounding
69
True or False
| highly ionized compound will be reabsorbed in the kidneys
False
70
Explain how ion trapping can lead to fetal distress during the administration of local anesthetics and opioids?
administration of OPIOID or LOCAL ANESTHETIC given to mom travels across PLACENTA to fetus (where pH is lower/more acidic). The non-ionized, lipid soluble portion that crosses is converted to an ionized form once in the baby’s lower pH environment, and so it gets stuck there and accumulates and can result in fetal distress
71
Ionization detail _ make an appropriate question
If HIGHLY IONIZED, has IMPAIRED absorption from GI, limited hepatic metabolism, and its EXCRETION UNCHANGED is facilitated at kidney (highly ionized compound will NOT BE REABSORBED)
72
What is phase I biotransformation?
Convert to polar metabolite
73
What is phase II biotranformation?
Conjugate with endogenous substrate to water soluble
74
Drug clearance from liver dependent on:
- hepatic blood flow,
- intrinsic ability of liver to irreversibly eliminate drug from the blood
- the extent of drug binding to plasma proteins or other blood constituents
75
Renal clearance of unchanged lipophilic drugs
Renal excretion of unchanged drug is only a modest role in overall elimination because lipophilic compounds filtered through the glomerulus are largely reabsorbed into the systemic circulation during passage through the renal tubules.
Drugs should be transformed into hydrophilic metabolites for elimination (first pass).
76
True or False:
Drugs that are cleared efficiently by the liver
with systemic clearances greater than 6 ml/min per kilogram, such as diltiazem, imipramine, lidocaine, morphine, and propranolol are restricted in their rate of elimination not by intrahepatic processes, but by the rate at which they can be transported in the blood to the liver
True
77
The adrenergic receptor antagonist propranolol is cleared from the blood at a rate of 16 ml/min per kilogram. What is the rate of clearance for a 70 kg man?
1120 ml/min in a 70-kg man
78
True or false:
| CLEARANCE: important concept to achieve steady state
true
79
true or false
Hofmann elimination is a temperature- and pH-dependent process, and therefore atracurium's rate of degradation in vivo is highly influenced by body pH and temperature: An increase in body pH favors the elimination process,[6][16] whereas a decrease in temperature slows down the process.[21] Otherwise, the breakdown process is unaffected by the level of plasma esterase activity, obesity,[22] age,[23] or by the status of renal[24][25][26][27] or hepatic function
true
80
What accounts for the shorter duration of action of ester local anesthetics as compared to amide local anesthetics
ester hydrolysis clearance of a drug from the blood by plasma cholinesterases
81
What are the major types of reactions used in metabolism of drugs?
oxidation
reduction
conjugation
hydrolysis
