Pharmacokinetics II metabolism, excretion & lifespan changes Flashcards
What is First Pass metabolism?
First Pass metabolism refers to the process by which the concentration of a drug is significantly reduced before it reaches systemic circulation.
True or False: First Pass metabolism occurs in the liver.
True
Fill in the blank: The primary organ involved in First Pass metabolism is the _____ .
liver
What is the primary purpose of First Pass metabolism?
The primary purpose is to metabolize and eliminate drugs before they enter the bloodstream.
Which route of drug administration is most affected by First Pass metabolism?
Oral administration
Multiple Choice: Which of the following drugs undergoes extensive First Pass metabolism? A) Aspirin B) Nitroglycerin C) Morphine D) Insulin
A) Aspirin
What is the effect of First Pass metabolism on drug bioavailability?
First Pass metabolism usually decreases drug bioavailability.
True or False: First Pass metabolism can lead to the formation of active metabolites.
True
Fill in the blank: First Pass metabolism primarily occurs in the _____ and _____ .
liver; intestines
What is the first site of drug absorption for orally administered drugs?
The gastrointestinal tract
Multiple Choice: Which phase of drug metabolism is primarily involved in First Pass metabolism? A) Phase I B) Phase II C) Both A and B D) None of the above
C) Both A and B
What is the term for the percentage of a drug that reaches systemic circulation after First Pass metabolism?
Bioavailability
True or False: First Pass metabolism is a crucial mechanism for drug detoxification.
True
Fill in the blank: The _____ enzyme system is primarily responsible for Phase I reactions in First Pass metabolism.
Cytochrome P450
What type of drugs are more likely to undergo significant First Pass metabolism?
Lipid-soluble drugs
Multiple Choice: Which factor does NOT affect First Pass metabolism? A) Age B) Liver function C) Drug formulation D) Route of elimination
D) Route of elimination
What can be a consequence of high First Pass metabolism on drug dosing?
Higher doses may be required to achieve therapeutic effects.
True or False: First Pass metabolism can vary significantly among individuals.
True
Fill in the blank: First Pass metabolism can be influenced by factors such as _____ , _____ , and _____ .
genetics; diet; concurrent medications
What is the role of the portal vein in First Pass metabolism?
The portal vein transports absorbed drugs from the gastrointestinal tract to the liver.
Multiple Choice: Which of the following can be a strategy to bypass First Pass metabolism? A) Sublingual administration B) Oral administration C) Rectal administration D) All of the above
A) Sublingual administration
What is the impact of First Pass metabolism on drug half-life?
It can shorten the effective half-life of a drug.
True or False: First Pass metabolism can result in complete drug elimination before reaching systemic circulation.
False
Fill in the blank: In some cases, First Pass metabolism can activate a prodrug into its _____ form.
active
What is biotransformation?
Biotransformation is the chemical modification made by an organism on a chemical compound.
What are the two main phases of biotransformation?
The two main phases of biotransformation are Phase 1 and Phase 2.
What is the primary function of Phase 1 biotransformation?
The primary function of Phase 1 biotransformation is to introduce or expose functional groups on the substrate.
True or False: Phase 1 biotransformation typically makes compounds more water-soluble.
False: Phase 1 biotransformation often makes compounds more reactive but not necessarily more water-soluble.
Name one common reaction type that occurs during Phase 1 biotransformation.
Common reaction types include oxidation, reduction, and hydrolysis.
What enzymes are primarily involved in Phase 1 biotransformation?
Cytochrome P450 enzymes are primarily involved in Phase 1 biotransformation.
Fill in the blank: Phase 1 biotransformation can convert lipophilic compounds into __________ compounds.
more polar
What is the primary function of Phase 2 biotransformation?
The primary function of Phase 2 biotransformation is to conjugate the substrate with endogenous substrates to increase water solubility.
True or False: Phase 2 reactions typically involve the addition of large polar groups.
True
Name one common type of reaction that occurs in Phase 2 biotransformation.
Conjugation reactions, such as glucuronidation, sulfation, and acetylation.
What is the role of UDP-glucuronosyltransferases in Phase 2 biotransformation?
UDP-glucuronosyltransferases catalyze the conjugation of glucuronic acid to substrates.
How do Phase 1 and Phase 2 biotransformation processes interact?
Phase 1 biotransformation often prepares substrates for Phase 2 reactions by introducing reactive groups.
Fill in the blank: Phase 1 reactions typically result in __________ of the parent compound.
activation or functionalization
What is the significance of biotransformation in drug metabolism?
Biotransformation is crucial for the detoxification and elimination of drugs and xenobiotics.
Multiple choice: Which phase of biotransformation is primarily responsible for detoxification? A) Phase 1 B) Phase 2
B) Phase 2
What is the outcome of Phase 2 biotransformation?
The outcome is the formation of more water-soluble metabolites that can be excreted from the body.
True or False: All drugs undergo both Phase 1 and Phase 2 biotransformation.
False: Not all drugs undergo both phases; some may only undergo one.
What is a potential consequence of impaired biotransformation?
Impaired biotransformation can lead to drug toxicity and accumulation of harmful substances.
Fill in the blank: Phase 1 biotransformation reactions often result in __________ metabolites.
active or toxic
Name two factors that can influence biotransformation.
Genetic factors and environmental factors such as exposure to other drugs.
What is the role of glutathione in Phase 2 biotransformation?
Glutathione is involved in conjugation reactions to detoxify reactive metabolites.
Multiple choice: Which of the following is NOT a Phase 1 reaction? A) Hydrolysis B) Glucuronidation C) Oxidation
B) Glucuronidation
What is the impact of age on biotransformation processes?
Age can affect the activity of enzymes involved in biotransformation, impacting drug metabolism.
What are active drug metabolites?
Active drug metabolites are the products of drug metabolism that retain pharmacological activity.
True or False: CYP enzymes are responsible for the metabolism of many drugs.
True
Fill in the blank: CYP stands for __________.
Cytochrome P450
What role do CYP enzymes play in drug interactions?
CYP enzymes can alter the metabolism of drugs, potentially leading to increased or decreased drug levels and effects.
Name one factor that can affect CYP enzyme activity.
Genetic variations, age, diet, and concurrent medications.
Multiple Choice: Which of the following is a common consequence of drug interactions involving CYP enzymes? A) Increased efficacy B) Increased toxicity C) Both A and B
C) Both A and B
What is the significance of understanding active drug metabolites in pharmacotherapy?
Understanding active drug metabolites is crucial for predicting therapeutic outcomes and potential side effects.
True or False: All drug metabolites are inactive.
False
What does the term ‘first-pass metabolism’ refer to?
The metabolism of a drug before it reaches systemic circulation, often involving CYP enzymes in the liver.
Short Answer: How can dietary substances affect CYP enzymes?
Certain foods and supplements can induce or inhibit CYP enzyme activity, altering drug metabolism.
Fill in the blank: The primary site of CYP enzyme activity is the __________.
liver
What is the impact of CYP450 polymorphisms on drug therapy?
CYP450 polymorphisms can lead to variations in drug metabolism, affecting drug efficacy and safety.
Multiple Choice: Which of the following can be a result of a drug-drug interaction involving CYP enzymes? A) Enhanced drug clearance B) Reduced drug absorption C) Altered drug metabolism
C) Altered drug metabolism
True or False: Inhibition of CYP enzymes can lead to increased plasma levels of certain drugs.
True
What is the role of enzyme induction in drug interactions?
Enzyme induction increases the activity of CYP enzymes, leading to enhanced metabolism and decreased drug levels.
Fill in the blank: The enzyme CYP3A4 is responsible for the metabolism of approximately __________% of clinically used drugs.
50
Short Answer: Why is it important to consider drug metabolites in clinical settings?
Drug metabolites may have therapeutic effects or toxicities that impact patient safety and treatment efficacy.
What is the relevance of pharmacogenomics in relation to CYP enzymes?
Pharmacogenomics studies how genetic variations affect drug metabolism via CYP enzymes, guiding personalized medicine.
Multiple Choice: Which of the following factors can lead to decreased CYP enzyme activity? A) Smoking B) Alcohol consumption C) Chronic illness
C) Chronic illness
True or False: All drugs that undergo CYP metabolism have active metabolites.
False
What is the potential consequence of a drug that is both a substrate and an inhibitor of a CYP enzyme?
It can lead to increased levels of the substrate drug, potentially causing toxicity.
Fill in the blank: The process by which CYP enzymes convert lipophilic drugs into more hydrophilic metabolites is known as __________.
metabolism
Short Answer: How do CYP enzyme inhibitors affect drug therapy?
CYP enzyme inhibitors can increase the concentration of drugs that are metabolized by those enzymes, leading to potential toxicity.
What is drug excretion?
The process by which drugs are eliminated from the body.
True or False: Drug excretion only occurs through the kidneys.
False
Name one major organ involved in drug excretion.
Kidneys
What is the primary route of drug excretion for most medications?
Renal excretion
Fill in the blank: The pH of urine can influence the __________ of drugs.
excretion
What role do liver enzymes play in drug excretion?
They metabolize drugs, making them easier to excrete.
True or False: Hydrophilic drugs are usually excreted more easily than lipophilic drugs.
True
Which factor can affect drug excretion: age, diet, or both?
Both
What is the significance of glomerular filtration rate (GFR) in drug excretion?
It indicates how well the kidneys are filtering blood to excrete drugs.
What is tubular secretion?
The active process of transferring drugs from the blood into the urine.
Name a factor that can decrease drug excretion.
Kidney disease
True or False: Drug interactions can affect the rate of excretion.
True
What is enterohepatic recirculation?
The recycling of drugs from the liver to the intestine and back to the liver.
Fill in the blank: The __________ of a drug can influence its excretion rate.
half-life
What is the effect of hydration status on drug excretion?
Dehydration can reduce urine output and slow excretion.
Name one method of drug excretion other than renal.
Biliary excretion
True or False: Protein binding can affect drug excretion.
True
What is the impact of pH on drug solubility and excretion?
It can alter the ionization of drugs, affecting their solubility.
How does the presence of diseases like diabetes affect drug excretion?
It can impair kidney function, thus reducing drug excretion.
Fill in the blank: Drug excretion can be affected by __________ factors.
physiological
What is the influence of age on drug excretion?
Elderly patients often have decreased renal function, affecting excretion.
True or False: All drugs are excreted unchanged in urine.
False
What is the primary mechanism by which drugs are excreted in bile?
Active transport
Name a physiological condition that can enhance drug excretion.
Increased urine flow
What does the term ‘clearance’ refer to in drug excretion?
The volume of plasma from which a substance is completely removed per unit time.
Fill in the blank: The __________ concentration of a drug can influence its excretion rate.
plasma
What does AMDE stand for?
Age-related changes in drug metabolism and elimination.
True or False: AMDE is consistent across all stages of human life.
False.
At which life stage is drug metabolism typically the highest?
In early adulthood.
Fill in the blank: AMDE can be significantly affected by __________ factors.
Physiological and biochemical.
What physiological change in elderly individuals affects drug elimination?
Decreased renal function.
True or False: Infants metabolize drugs at a rate similar to adults.
False.
Which age group is often more sensitive to drug effects due to immature liver function?
Neonates and infants.
Multiple Choice: Which of the following factors can influence AMDE? A) Age B) Gender C) Genetics D) All of the above
D) All of the above.
What is the primary reason for altered drug metabolism in the elderly?
Decreased liver mass and hepatic blood flow.
Short answer: How does pregnancy affect AMDE?
Pregnancy can lead to increased blood volume, altered metabolism, and changes in renal function.
True or False: Children metabolize drugs faster than adults.
True.
What is the impact of obesity on drug metabolism?
Obesity can alter volume of distribution and clearance rates.
Fill in the blank: The __________ phase of life is characterized by the highest metabolic rate for most drugs.
Young adult.
What is one effect of aging on drug absorption?
Slower gastric emptying.
Multiple Choice: Which age group may require dose adjustments for certain medications? A) Infants B) Adolescents C) Seniors D) All of the above
D) All of the above.
Short answer: Describe one way genetics can influence AMDE.
Genetic polymorphisms can lead to variations in enzyme activity affecting drug metabolism.
True or False: Drug interactions become less significant as individuals age.
False.
What is the term for the study of how drugs affect the body?
Pharmacodynamics.
Fill in the blank: __________ factors can include diet, co-existing diseases, and medications.
Environmental.
At what stage of life does the liver’s ability to metabolize drugs begin to decline?
Around the age of 40.
Short answer: Name one common medication that requires careful dosing in the elderly.
Warfarin.
True or False: Drug clearance rates are generally higher in children than in adults.
True.
What physiological change in older adults can lead to increased drug half-life?
Decreased renal clearance.
Multiple Choice: Which enzyme system is primarily responsible for drug metabolism? A) CYP450 B) UGT C) SULT D) All of the above
A) CYP450.
Short answer: How does hydration status affect drug metabolism in the elderly?
Dehydration can reduce renal function and increase drug concentrations.
