Pharmacokinetics Key Concepts

Gentamicin typically has a half-life of 2-3 hours. However, in cases of kidney accumulation, its half-life extends to 53 hours. What is this type of half-life prolongation called?

A patient experiencing an ST-elevation myocardial infarction is treated with aspirin, propranolol, clopidogrel, and atorvastatin. Which of these medications is primarily metabolized by CYP2D6?

Drug metabolism in the liver occurs in two phases: catabolic reactions (Phase 1) and synthetic reactions (Phase 2). Which of the following is a Phase 1 reaction?

A young girl is brought to the ER after overdosing on an unknown drug. To enhance its elimination, urine acidification is considered. Which of the following drugs, if taken in excess, would have its elimination rate increased by acidifying the urine?

A patient receives Drug A and Drug B intravenously every 24 hours for six days. A graph plotting drug concentration in the blood over time reveals that drug A does not maintain therapeutic levels when administered every 24 hours. What conclusion can be drawn from this observation?

A 30-year-old pregnant woman, at 22 weeks gestation with no known health issues, is prescribed mefloquine, a highly protein-bound drug, for malaria prophylaxis before traveling. What effect can be anticipated regarding mefloquine's distribution in the patient?

A drug is eliminated from the body primarily through hepatic metabolism. Which patient characteristic would most significantly decrease the rate of drug elimination, potentially requiring dosage adjustments?

A drug is known to undergo first-pass metabolism. How does this phenomenon affect the drug's bioavailability after oral administration?

A patient with renal impairment is prescribed a drug that is primarily eliminated by glomerular filtration. What adjustments should be made to the drug regimen to ensure patient safety?

A drug with a narrow therapeutic window is administered to a patient. Which of the following strategies is most important to ensure safe and effective treatment?

A drug is known to be a substrate of CYP3A4. Concurrent administration of which substance would most likely lead to a decrease in the plasma concentration of the drug?

A new drug is being developed. Studies show it has a very large volume of distribution. What can be inferred about the drug's distribution characteristics?

A drug has a half-life of 4 hours. Assuming first-order kinetics, approximately how long will it take for the drug to reach steady-state concentration after continuous intravenous infusion?

Therapeutic drug monitoring is essential when a drug's effect is difficult to measure directly. Which of the following drugs typically requires therapeutic drug monitoring due to its narrow therapeutic index and potential for toxicity?

A 7-year-old child with a history of rheumatic fever is on erythromycin prophylaxis. Which of the following laxatives should be avoided due to the potential for increased risk of arrhythmia when used concurrently with erythromycin?

A 5 ml ampoule contains 5 mg/ml of nitroglycerin (NTG). This ampoule is added to normal saline to create a 500 ml solution. What is the infusion rate (in drops/min) required to deliver NTG at 10 mcg/min, using a micro drip set (60 drops/ml)?

Which statement accurately describes a key factor influencing drug distribution within the body?

A 57-year-old male post-STEMI is prescribed an antiplatelet medication. Knowing that the patient's CYP2C19 genotype can influence the effectiveness of certain drugs, which antiplatelet medication's efficacy is most likely to be affected by this genetic variation?

A patient is prescribed a drug with a known maintenance dose. What is the primary purpose of calculating and administering a maintenance dose?

A drug's response cannot be easily measured through direct clinical observation. In which of the following cases would therapeutic drug monitoring (TDM) be LEAST necessary?

Which of the following is the MOST common Phase II metabolic reaction?

A patient receiving erythromycin is also prescribed a laxative. Which of the following drug interactions is a major concern when considering the co-administration of erythromycin with cisapride?

Phase II drug metabolism reactions primarily result in which of the following outcomes?

A patient presents with toxicity due to an overdose of a weak base drug. Which of the following strategies would MOST effectively promote urinary excretion?

A patient overdoses on a drug. The physician decides to alter the urinary pH to enhance the drug's excretion. If the drug is a weak acid, which of the following changes to urinary pH would be MOST appropriate?

Which of the following Phase II metabolic reactions involves the addition of a two-carbon fragment derived from acetyl-CoA?

Which of the following Phase II metabolic reactions involves the addition of a methyl group?

Why does thiopentone have a short duration of CNS effect despite high plasma protein binding?

A patient with renal calculi is prescribed tramadol. Which of the following statements correctly explains how urine pH affects tramadol excretion?

A patient is brought to the emergency department exhibiting signs of amphetamine overdose. Knowing that amphetamine is a weak base, which of the following interventions is MOST likely to increase the drug's elimination?

Which of the following best describes how changes in urinary pH affect the tubular reabsorption of drugs in the kidneys?

Which of the following is true regarding the binding characteristics of acidic and basic drugs in plasma?

Where are basic drugs primarily ionized and absorbed in the body?

Which of the following Phase II drug metabolism reactions is the most common?

During drug metabolism, what is the primary difference between Phase I and Phase II reactions?

In the context of drug metabolism in older adults, which statement accurately describes the relative impairment of Phase I and Phase II reactions?

A drug is administered intravenously and its plasma concentration decreases rapidly within the first 15 minutes, followed by a slower decline. What is the most likely explanation for this phenomenon?

Why do weak acids ionize more in alkaline urine?

In a case of methotrexate poisoning, why is urine alkalinized?

Drug A's concentration reaches zero before the next dose is administered. What can be concluded about Drug A?

How does Drug A's behavior differ from Drug B's behavior, given Drug B exhibits cumulative properties?

A patient receives fentanyl via a transdermal patch for postoperative pain. What is a primary advantage of using this route of administration?

Why are transdermal patches suitable for administering drugs like fentanyl and rotigotine?

A new drug is developed that is a weak base. How would acidification of the urine affect the drug's excretion?

A drug is known to undergo significant first-pass metabolism. Which route of administration would be best to avoid this effect?

Pharmacokinetics

Pharmacodynamics

Clinical Trials

Parasympathetic System

Sympathetic System

NSAIDs

Vancomycin Mechanism

Drug Efflux

Terminal Half-Life

CYP2D6

Propranolol Metabolism

Phase 1 Metabolism

Hydroxylation

Urine Acidification

Salicylate Elimination

Therapeutic Drug Levels

Phase 2 Reactions

Glucuronidation

Acetylation

Methylation

Sulfation

Glycine Conjugation

Urine pH and Drug Reabsorption

Amphetamine Poisoning Treatment

Thiopentone's CNS effect duration

Thiopentone Redistribution

Basic drug excretion

Weakly Basic Drugs (Examples)

Drug binding proteins

Basic Drug Absorption

Most common Phase II reaction

Phase I vs. Phase II drug metabolism

Maintenance Dose

Therapeutic Drug Monitoring

Cisapride Risk

Drug Distribution Factor

Clopidogrel & CYP2C19

NTG Concentration

NTG Infusion Rate

Weak Acids in Alkaline Urine

Non-Cumulative Drug

Cumulative Drug

Drug A Clearance Time

Transdermal Route

Transdermal Benefit

Transdermal Drug Properties

Transdermal Advantage