Loading...
Question 1
What is pharmacokinetics?
how the body processes drugs absorption, distribution, metabolism, and excretion
Question 2
What is pharmacodynamics?
how drugs affect the body and the body's response to them
Question 3
What is pharmacotherapeutics?
the selection and use of drugs for the treatment of diseases
Question 4
What is the first phase of pharmacokinetics?
Drug Absorption
Question 5
What is the second phase of pharmacokinetics?
Drug Distribution
Question 6
What is the third phase of pharmacokinetics?
Drug Metabolism
Question 7
What is the fourth phase of pharmacokinetics?
Drug Elimination
Question 8
What is bioavailability?
The fraction of the administered dose that reaches the systemic circulation and is available to exert its pharmacological effect.
Question 9
Important factors affecting absorption
dosage forms and route of administration first pass metabolism
Question 10
What is the rate of transport for
unionized
drugs across a membrane?
• diffuse passively according to the concentration gradient • influenced by the lipophilicity.
Question 11
How does the ionization degree of a drug affect its transport across a membrane?
Only
unionized
form can diffuse across biologic membranes
Question 12
what determines the ionization degree
pKa of the drug and pH of its environment
Question 13
What is the Henderson-Hasselbalch equation used for?
relates dissociation of a weak acid/base and the pH of a biological medium
Question 14
What does pKa represent in the context of the Henderson-Hasselbalch equation?
It is the acid dissociation constant of a drug.
Question 15
How does the ionization status of a drug affect its absorption and excretion?
status affects drug's ability to cross biological membranes and be excreted
Question 16
What is the relationship between pH and the predominant forms of a weak acid HA and its conjugate base A-?
pH < pKa: HA and BH+ predominate pH > pKa: A- and B predominate
Question 17
What is the significance of pH = pKa in the context of a weak acid HA and its conjugate base A-?
pH = pKa: concentrations of HA and A- are equal
Question 18
What is the ionization behavior of a weak base in acidic pH?
weak base is ionized in acidic pH
Question 19
In what pH environment is a weak acid ionized?
weak acid is ionized in basic pH
Question 20
How does the ionized form of a drug affect its excretion?
ionized form = more hydrophilic = more excreted Nonionized = more lipophilic = more absorbed
Question 21
What is drug distribution in pharmacology?
dissemination of drug from blood to the extracellular fluids and tissues
Question 22
How does the distribution rate of drugs vary among different tissues?
distribution rate depends on blood flow to organs brain, liver, and kidney > muscle, skin> fat and bone
Question 23
What is the formula for Volume of Distribution (Vd)?
Vd = Amount of drug in the body tissue (mg) / C0 (mg/L)
Question 24
What does a low and high Vd indicate?
Low: extensive plasma protein binding High: may indicate extensive binding of drug to tissue sites
Question 25
What is the importance of albumin in drug binding?
Albumin is an important plasma protein for drug binding.
Question 26
Which drugs are bound by serum albumin?
binds many acidic drugs
Question 27
what drugs are bound by α1-acid glycoprotein
many basic drugs
Question 28
What is sequestration
term for the process where drugs are actively transported into tissues
Question 29
What is the significance of 'free' drug in pharmacology?
Pharmacologically active drug
Question 30
How do tissue reservoirs affect drug action?
serve as a source of the drug and prolong its actions can cause local drug toxicity
Question 31
True/False: more compartments of distribution the longer the drug stays in body
True
Question 32
What is the main site for drug metabolism?
Liver
Question 33
What enzymes are involved in drug metabolism?
Hepatic microsomal enzymes, including the cytochrome P450 family
Question 34
What is the role of the Cytochrome P-450 (CYP) enzyme group?
enzyme group responsible for most drug oxidation reactions (70%)
Question 35
Where are the CYP enzymes located?
liver, specifically in the endoplasmic reticulum
Question 36
Which CYP enzymes are primarily responsible for the metabolism of most drugs?
CYP2C CYP2D CYP3A
Question 37
What are CYP 450 inducers and what effect do they have on drug metabolism?
• substances that ↑ activity of CYP450 enzymes • increased drug metabolism, decrease plasma concentrations of drug • suboptimal therapeutic effects
Question 38
CYP450 enzyme inducers
• chronic alcohol use • phenobarbital • rifampicin (anti-TB medication) • phenytoin • St. John’s Wort (OTC drug)
Question 39
what are CYP450 inhibitors effects
• significant increases in plasma drug concentration • adverse effects or drug toxicity
Question 40
examples of CYP 450 inhibitors
• omeprazole • cimetidine • macrolide antibiotics • azole antifungals • grapefruit juice
Question 41
What are the two metabolic phases of drug metabolism?
Phase I and Phase II
Question 42
What are the main reactions involved in Phase I metabolism?
Oxidation, reduction, and/or hydrolysis
Question 43
What is the typical fate of a drug after Phase I metabolism?
Activated, unchanged, or inactivated
Question 44
What are Phase I metabolic reactions?
•
non-synthetic
reactions catalyzed by hepatic microsomal enzymes, • oxidation, reduction, and hydrolysis → hydrophilic compounds
Question 45
What are Phase I reaction results
• Inactivation of drugs (many drug groups). • Conversion: inactive drug → active metabolite (codeine to morphine, cortisone to cortisol) • Conversion: drug → toxic compound (methanol to formaldehyde)
Question 46
Which enzymes are mainly involved in Phase I reactions?
hepatic microsomal enzymes, CYP450 enzymes
Question 47
What are Phase II metabolic reactions?
•
Synthetic reactions
• conjugation of parent compound/its metabolite with glucuronic acid, acetic acid, or glycine
Question 48
How do Phase II reactions typically affect drug activity?
usually lead to drug inactivation
Question 49
Phase II reaction pathway
• convert drug to more hydrophilic form for renal excretion • lead to drug inactivation
Question 50
What is portal circulation in the context of drug metabolism?
rate of blood flow to the liver and plasma protein binding
Question 51
How does liver function affect drug metabolism?
Patients with decompensated livers will have lower metabolic activity.
Question 52
What role do genetic factors play in drug metabolism?
Individuals vary in their inherited ability to metabolize drugs.
Question 53
What is the main organ for drug excretion?
The kidney
Question 54
what are the routes of elimination
urine, feces, saliva, sweat, tears, milk and lungs
Question 55
What is renal clearance of drugs?
measures the volume of plasma that is cleared from the drug per minute
Question 56
What is the formula for calculating renal clearance (CL)?
CL (ml/min) = Rate of drug elimination / plasma drug concentration
Question 57
What are the three mechanisms by which renal excretion occurs?
Glomerular filtration active transport via plasma protein binding tubular reabsorption
Question 58
How does glomerular filtration contribute to renal excretion?
Most chemicals and drugs with low molecular weight are excreted by glomerular filtration.
Question 59
What is first-order elimination in drug kinetics?
constant fraction of drug is eliminated per unit time depending on the plasma drug concentration most drugs
Question 60
What is zero-order elimination in drug kinetics?
constant amount of drug is eliminated per unit time regardless of plasma concentration
Question 61
What is the definition of half-life (t ½)?
The time needed for the plasma drug concentration to be reduced by 50%
Question 62
Which type of drug kinetics does elimination half-life apply to?
First order kinetics
Question 63
How long does it take for most drugs to be cleared from the body?
After 4-5 half-lives
Question 64
What is the formula for calculating half-life (t½)?
t½ = 0.693 Vd/CL
Question 65
What is the effect of a CYP inducer on clearance (CL) and half-life (t½)?
A CYP inducer increases CL and decreases t½.
Question 66
How many half-lives are typically required to reach a steady state in drug kinetics?
Usually, 4 half-lives are required to reach a steady state.
Question 67
What is pharmacodynamics?
The study of how drugs interact with the body to produce a pharmacological effect.
Question 68
What percentage of drug targets are receptors according to the pie chart?
47%
Question 69
T/F: the magnitude of a pharmacological response is proportional to the number if receptors available for a drug
True
Question 70
What is a ligand and ligand detector in pharmacodynamics?
ligand: substance that binds to a receptor (drug) ligand detector: receptor
Question 71
How do drug-receptor interactions typically occur?
Drug-receptor interactions are usually reversible.
Question 72
What are the three stages of signal transduction?
Reception, Transduction, Cell Response
Question 73
What happens during the Reception stage of signal transduction?
Receptors bind to ligands
Question 74
What occurs during the Transduction stage of signal transduction?
Receptor protein changes and activate intracellular molecules (2nd messengers)
Question 75
What are Ligand-gated ion channels and how do they function?
• cell surface receptors • open in response to ligand binding • allowing ion exchange → initiates cell signaling
Question 76
Provide an example of a Ligand-gated ion channel and its ligand.
Cholinergic nicotinic receptors -- acetylcholine
Question 77
What are G protein-coupled receptors?
• Seven-transmembrane receptors • common drug targets for hydrophilic molecules
Question 78
What happens after G protein-coupled receptors are activated?
G proteins bind secondary messengers → signal amplification
Question 79
What are some effector molecules activated by G protein-coupled receptors?
Adenyl cyclase (cAMP) and phospholipase C (increase calcium concentration).
Question 80
What are enzyme-linked receptors and how do they function?
• cell surface receptors • undergo conformational changes upon ligand binding • increase intracellular enzyme activity
Question 81
What are intracellular receptors and how do they work?
• receptors that can diffuse through the plasma membrane • bind to hydrophobic ligands • interact with specific DNA sequences to activate/deactivate transcription of target genes
Question 82
What is receptor-mediated drug action?
process by which drugs interact with specific receptors on/within cells to produce a biological effect
Question 83
What is the definition of intrinsic activity?
measure of the drug's ability to activate a receptor after binding
Question 84
What are full agonists
• drugs capable of binding to receptors causing maximal activation • intrinsic activity equal to 1
Question 85
what are partial agonists?
• can occupy all receptors without producing maximal response • Intrinsic activity<1
Question 86
What is an antagonist in pharmacology?
• drug that binds to the receptor
without activation
or initiating a response • blocks action of an agonist or substance that activates that receptor
Question 87
What is a competitive antagonist?
binds to the receptor in the same site for the agonist without causing receptor activation
Question 88
What is a noncompetitive antagonist?
noncompetitive antagonist does not bind to the same site as an agonist
Question 89
What is a competitive antagonist?
A medication that reversibly binds to the same receptor site where an agonist binds but does not activate it.
Question 90
What is receptor downregulation?
where repeated exposure to agonists leads to a diminished response of the cell
Question 91
What is the term for the diminished response to repeated exposure to agonists?
Tolerance or tachyphylaxis.
Question 92
What is desensitization or tachyphylaxis?
• rapid decrease in the body's responsiveness to a drug • often occurring with the initial dose
Question 93
How does tolerance differ from desensitization or tachyphylaxis?
• Tolerance: more gradually, repeated doses • desensitization/tachyphylaxis: rapid, initial dose, not fixed with increased dose
Question 94
What is EC50
• Effective Concentration 50 • concentration of a drug that produces 50% of its maximum response
Question 95
What is the maximal efficacy of a drug (Emax)
drug occupying all receptors, yielding the maximum response
Question 96
What is the definition of potency in pharmacology?
concentration (EC50) of a drug required to produce 50% of its maximal response
Question 97
How is potency used in comparing drugs?
Potency is used to compare drugs within the same group.
Question 98
What is efficacy in pharmacology?
ability of a drug to elicit the maximal pharmacologic response
Question 99
How does efficacy differ from potency?
Efficacy is the maximal response potency is the dose required to achieve that response
Question 100
What is the treatment for opioid overdose?
Naloxone
Question 101
What is pharmacotherapeutics?
The study of the use of drugs in the treatment of diseases.
Question 102
What does pharmacotherapeutics monitor?
• drug efficacy (therapeutic index) • safety margin • tolerance/dependence • interactions • side/adverse effects
Question 103
What does the quantal dose-response relationship record?
records the population response to a given drug
Question 104
What is the definition of Effective dose 50 % (ED 50)?
minimal drug concentration that induces specified therapeutic effect in 50 % of subjects' pool
Question 105
What is the definition of Toxic dose 50 % (TD 50)?
The drug concentration sufficient to induce adverse effects in 50 % of the subjects' pool.
Question 106
What is the definition of Lethal dose 50 (LD 50)?
drug concentration that induces death in 50% of the recipient pool
Question 107
How is the Therapeutic index (TI) calculated?
• LD50/ED50 • TD50/ED50
Question 108
T/F: therapeutic index is directly proportional to drug safety
true
Question 109
What is the definition of the margin of safety in pharmacology?
dose range between the minimum therapeutic dose and the toxic dose
Question 110
How does a larger therapeutic index relate to the safety of a drug?
larger therapeutic index = safer administered drug
Question 111
What is Pharmacogenetics?
how genetic differences influence drug response
Question 112
what is pharamcogenomics
• variants in large number of genes • genetic influences on drug response in an individual or across a population
Question 113
What percentage of adverse drug reactions are involved in Phase I enzyme metabolisms?
60%
Question 114
What are metabolizer phenotypes
• ultrarapid metabolizers • intermediate metabolizers • poor metabolizers • normal metabolizers
Question 115
What is the definition of an ultrarapid metabolizer?
has an accelerated drug metabolism with a higher rate of drug elimination and possibly lower efficacy
Question 116
What is the definition of a poor metabolizer?
• has slower drug metabolism leading to drug accumulation • higher potential for adverse events, drug-drug interactions, and lower efficacy
Question 117
What does Category A indicate about the potential risk to the fetus in the first trimester of pregnancy?
No potential risk
Question 118
Category B pregnancy risk status
• Animal studies failed to demonstrate a risk • no adequate, well-controlled studies in pregnant women
Question 119
Category C pregnancy risk status
• Animal studies demonstrated
adverse effect
on the fetus • no adequate, well-controlled studies in humans
Question 120
What does Category D indicate about the potential risk to the fetus based on human studies?
• positive evidence of human fetal risk • adverse reaction data from investigation or human studies
Question 121
Category X pregnancy risk status
• Studies in animals/humans have demonstrated fetal abnormalities • positive evidence of human fetal risk
Question 122
What year did the FDA replace the prescription drug categories with a new labeling system?
2016
Question 123
What is the new labeling system for prescription drugs called?
Pregnancy and lactation labeling final rule
Question 124
What information is provided in the pregnancy section of the new labeling system?
• Pregnancy: info relevant to pregnant women (dosing, fetal risks) • Lactation: safety of drug while breastfeeding (amount in milk, effects on breastfed child) • Reproductive potential: info on pregnancy testing, contraception, infertility
Question 125
What is pharmacokinetic drug interaction?
A drug alters the absorption, distribution, metabolism, or excretion of another drug, changing the amount available to produce the desired effect.
Question 126
What is pharmacodynamic drug interaction?
Drugs influence each other's effects directly Ex. 2 meds ↑ BP Ex. med ↑BP by opposing effect of other med
Question 127
What is synergistic effect?
Two drugs increase the effect of each other, such as two drugs increasing blood pressure.
Question 128
What is potentiation
a drug with no effect can enhance the effect of a 2nd drug 0+1 = 2