Pharmacology: Drug Distribution Quiz

<p>The free fraction would increase, as there are fewer binding sites for the drug on albumin. (C)</p> Signup and view all the answers

<p>Only the unbound drug is pharmacologically active and can interact with its target site. (C)</p> Signup and view all the answers

<p>Patient's age (D)</p> Signup and view all the answers

<p>The patient is experiencing phenytoin toxicity due to an increased free fraction. (C)</p> Signup and view all the answers

<p>Warfarin (C)</p> Signup and view all the answers

<p>Increased lipophilicity (D)</p> Signup and view all the answers

<p>To introduce or expose functional groups (C)</p> Signup and view all the answers

<p>Glucuronidation of morphine to morphine-6-glucuronide (C)</p> Signup and view all the answers

<p>Hydroxyl (-OH) (B)</p> Signup and view all the answers

<p>Oxidizing drugs (C)</p> Signup and view all the answers

<p>UDP-glucuronosyltransferases (A)</p> Signup and view all the answers

<p>Codeine (B)</p> Signup and view all the answers

<p>They always result in inactive metabolites (A)</p> Signup and view all the answers

<p>Oxidizing drugs to more polar metabolites (A)</p> Signup and view all the answers

<p>Sulfatase (B)</p> Signup and view all the answers

<p>Acetaminophen is conjugated with glutathione by GST to prevent liver toxicity. (B)</p> Signup and view all the answers

<p>Codeine (B)</p> Signup and view all the answers

<p>Increased drug metabolism and shorter half-life (B)</p> Signup and view all the answers

<p>Rifampin (D)</p> Signup and view all the answers

<p>Decreased drug metabolism and longer half-life (A)</p> Signup and view all the answers

<p>Grapefruit juice (D)</p> Signup and view all the answers

<p>Drug metabolism in the liver (A)</p> Signup and view all the answers

<p>Distribute rapidly into tissues (B)</p> Signup and view all the answers

<p>Distribution of the drug into tissues (A)</p> Signup and view all the answers

<p>Both curves plateau at a steady-state concentration (D)</p> Signup and view all the answers

<p>Aminoglycosides (D)</p> Signup and view all the answers

<p>Drug movement from the central compartment to peripheral tissues (C)</p> Signup and view all the answers

<p>Heart failure (B)</p> Signup and view all the answers

<p>The BBB restricts the entry of polar drugs. (A)</p> Signup and view all the answers

<p>Increased free phenytoin concentration, potentially leading to toxicity. (A)</p> Signup and view all the answers

<p>Hypotension (C)</p> Signup and view all the answers

<p>The extent of drug distribution into tissues. (D)</p> Signup and view all the answers

<p>The drug is predominantly concentrated in the plasma. (C)</p> Signup and view all the answers

<p>To rapidly achieve therapeutic drug levels. (C)</p> Signup and view all the answers

<p>F (B)</p> Signup and view all the answers

<p>Digoxin (D)</p> Signup and view all the answers

<p>A larger Vd indicates a greater distribution of the drug into tissues. (D)</p> Signup and view all the answers

<p>Muscle (A)</p> Signup and view all the answers

<p>The central compartment contains organs specialized for drug metabolism and excretion. (B)</p> Signup and view all the answers

<p>Alpha-1-Acid Glycoprotein (B)</p> Signup and view all the answers

<p>Drugs are initially distributed to the central compartment before reaching the peripheral compartment. (D)</p> Signup and view all the answers

<p>Free drug concentration increases because less albumin is available for binding. (D)</p> Signup and view all the answers

<p>Hypoalbuminemia (D)</p> Signup and view all the answers

<p>Cyclosporine (A)</p> Signup and view all the answers

<p>Drug elimination can occur through multiple processes, including metabolism, excretion, and other mechanisms. (D)</p> Signup and view all the answers

Factors include organ blood perfusion, lipid solubility, pH differences, protein binding, and disease states.

Highly perfused organs like heart, liver, and kidneys receive drugs more rapidly due to their blood flow.

Lipid-soluble (lipophilic) drugs can easily cross cell membranes and distribute in tissues.

Drugs that are bound to proteins are restricted to the plasma, while unbound drugs can distribute freely.

Marked between 0 to ~2 hours, this phase shows a steep decline in plasma concentration as the drug moves to tissues.

Both curves show initial drug distribution but differ in shape; plasma declines sharply while tissue increases gradually first.

Assumes instant drug distribution throughout the body with no delay between plasma and tissues.

Assumes an initial distribution phase from plasma to tissues before drug elimination occurs, common in lipophilic drugs.

Organs with high blood flow: heart, liver, kidneys, lungs, blood plasma.

Less perfused organs and tissues like muscle, fat, skin, bone, and CSF.

Mainly occurs in the central compartment via liver, kidneys, and lungs.

Major plasma protein that binds drugs, especially lipophilic ones.

Carrier protein that binds basic (cationic) drugs in plasma.

Transport proteins (HDL, LDL, VLDL) that bind lipophilic drugs.

Highly bound to albumin; hypoalbuminemia increases free drug levels.

Lower albumin results in more active phenytoin, increasing toxicity risk.

90% of a drug is bound to plasma proteins while 10% is free and active.

Proteins that increase in concentration during inflammation, infection, and stress.

A major acute-phase protein that binds to basic drugs.

Indicates extensive distribution of a drug into tissues rather than plasma.

High lipophilicity, low plasma protein binding, and tissue binding increase Vd.

Only free drug is pharmacologically active; changes can affect activity.

Includes changes in protein binding and drug-drug interactions.

A family of enzymes involved in oxidation reactions, metabolizing many drugs.

A specific CYP enzyme that metabolizes around 50% of drugs, such as midazolam.

An enzyme that catalyzes glucuronidation, a type of Phase 2 metabolism.

Enzyme that detoxifies harmful metabolites by conjugating them with glutathione.

Involves functionalization reactions by enzymes such as CYP and esterases.

Process that increases the synthesis and activity of drug-metabolizing enzymes, enhancing drug metabolism.

Process that decreases enzyme activity, leading to slower metabolism and potential toxicity.

Codeine is a prodrug that metabolizes into the active analgesic morphine.

Occurs when one drug competes with another for the same binding site, leading to increased free drug concentration.

A drug that is 90% bound to albumin; increased free levels can lead to toxicity.

A drug that competes with phenytoin for albumin binding sites, potentially raising phenytoin's free concentration.

A pharmacokinetic parameter indicating how extensively a drug distributes through the body versus plasma.

Indicates a drug mostly remains in the plasma; example: warfarin.

Indicates a drug extensively distributes into tissues; example: digoxin.

An initial higher dose of a drug given to quickly achieve therapeutic levels.

LD = (Vd × target concentration) / bioavailability.

Converts lipophilic drugs to hydrophilic metabolites for excretion, detoxification, and activation.

Increased water solubility and reduced membrane crossing enhance renal excretion.

Functionalization reactions introducing functional groups through oxidation, reduction, or hydrolysis.

Oxidation (e.g., Lidocaine to Monoethylglycinexylidide) and Hydrolysis (e.g., Aspirin to Salicylic Acid).

Conjugation reactions forming highly water-soluble products for easier excretion by linking to endogenous molecules.

Glucuronidation (e.g., Morphine to Morphine-6-glucuronide) and Sulfation (e.g., Acetaminophen to Acetaminophen sulfate).

A Phase 1 metabolic reaction, such as N-demethylation converts Codeine to Morphine.

Hydroxyl, Carboxyl, Amine, and Sulfhydryl groups are likely to undergo conjugation.