ADME: Drug Absorption and Metabolism

<p>Blood -&gt; Kidney -&gt; Urine (C)</p> Signup and view all the answers

<p>Due to their large molecular size, limiting their ability to cross membrane barriers. (C)</p> Signup and view all the answers

<p>Does not require energy and results in equal concentration on both sides at equilibirum. (D)</p> Signup and view all the answers

<p>Active transport requires energy to move substrates against a concentration gradient, while passive facilitated diffusion does not. (B)</p> Signup and view all the answers

<p>The unchanged drug moves from the administration site to the measurement site, typically plasma. (C)</p> Signup and view all the answers

<p>Low lipophilicity (LogP). (D)</p> Signup and view all the answers

<p>Intestinal absorption can lead to metabolism and biliary excretion, altering the drug before it reaches systemic circulation. (C)</p> Signup and view all the answers

<p>Increased lipophilicity increases blood-brain barrier permeability. (A)</p> Signup and view all the answers

<p>The tissue contains fenestrations. (A)</p> Signup and view all the answers

<p>Drugs are distributed via the systemic circulation to various tissues and organs in the body. (B)</p> Signup and view all the answers

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

<p>They are large molecules and substrates of efflux transporters. (A)</p> Signup and view all the answers

<p>Charged molecules move slower across membranes. (D)</p> Signup and view all the answers

<p>ADME processes occur simultaneously, with the rates of each process affecting the final drug exposure profile. (B)</p> Signup and view all the answers

<p>The irreversible loss of drug from the site of measurement, which includes both elimination and distribution. (B)</p> Signup and view all the answers

<p>To prevent the entry of toxins and drugs into the brain. (A)</p> Signup and view all the answers

<p>The drug in solution (solvated): a chemical entity (B)</p> Signup and view all the answers

<p>Movement of drug from one side of the cell to another across the phospholipid bilayer. (D)</p> Signup and view all the answers

<p>Lipophilicity, charge, and molecular size of the substance. (D)</p> Signup and view all the answers

<p>The fraction of drug that reaches the portal vein, escaping destruction within the walls of the GIT. (A)</p> Signup and view all the answers

<p>It is independent of lipophilicity, charge, or molecular size (up to ~500g/mol). (A)</p> Signup and view all the answers

<p>The metabolism of a drug as it passes through the intestinal wall and liver, reducing the amount reaching systemic circulation. (D)</p> Signup and view all the answers

<p>It reduces drug absorption by holding the drug in the GIT. (C)</p> Signup and view all the answers

<p>Reduced amount of drug reaching systemic circulation. (B)</p> Signup and view all the answers

<p>Hydrolysis of Penicillin G in the stomach's acidic environment, resulting in inactive products. (C)</p> Signup and view all the answers

<p>The drug is primarily distributed within the plasma volume. (D)</p> Signup and view all the answers

<p>A higher f_u indicates less protein binding. (A)</p> Signup and view all the answers

<p>No, f_ut cannot be reliably predicted from f_ub. (C)</p> Signup and view all the answers

<p>Changes in total drug concentration (C) correlate linearly with changes in unbound drug concentration ($C_u$). (A)</p> Signup and view all the answers

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

<p>They exhibit selective affinity for α-1 acid glycoprotein. (D)</p> Signup and view all the answers

<p>It leads to a smaller V (V &lt; 1 l/kg). (D)</p> Signup and view all the answers

<p>It is a relatively weak interaction with a modest restrictive influence on drug substrate. (B)</p> Signup and view all the answers

<p>$f_{ub} = C_u / C_t$ (C)</p> Signup and view all the answers

Volume of water inside cells, approximately 3L in a 70kg man.

Volume of fluid outside cells, about 12L, includes interstitial fluid.

Relates drug amount in body to its concentration in plasma or blood.

Drugs may bind to plasma and tissue proteins, affecting their volume and action.

Concentration of drug that is not bound to proteins, influencing drug activity.

A drug must be dissolved to cross cell membranes effectively.

Movement of substances down a concentration gradient without energy. Most common transport mechanism for drugs.

A type of passive transport using carrier proteins that do not require energy, highly specific to substrates.

Transport against a concentration gradient using energy (ATP), allows for directional movement of substances.

Drug permeability decreases as molecular size increases; larger molecules are less likely to permeate gut membranes.

A measure of how well a drug partitions between octanol and water; higher lipophilicity means better membrane permeability.

Charged molecules move slower across membranes; drugs exist in ionized and unionized forms based on pH and pKa.

A selective barrier with tight junctions that limits drug permeability; efflux transporters can remove drugs from the brain.

The process where a drug enters systemic circulation from the site of administration.

When a drug is administered outside the blood vessels, e.g., orally.

Achieved when drug concentration in blood becomes relatively uniform.

The process of a drug spreading throughout the body's tissues and organs post-absorption.

The conversion of one chemical compound to another, primarily in the liver.

The irreversible removal of unchanged drugs from the body, primarily through kidneys.

The combined processes of Absorption, Distribution, Metabolism, and Excretion.

Movement of drugs across cell membranes without energy, through the phospholipid bilayer.

Thickness of biological membranes that affects drug transport.

Proteins that facilitate movement of substances across membranes.

Fraction of an orally administered drug reaching systemic circulation.

Process where drugs are metabolized before reaching systemic circulation.

Fractions representing absorption stages in bioavailability: intestinal, portal vein, liver.

Proteins that reduce drug absorption by pumping it out of the cells.

Hypothetical volume that a drug would occupy in the body.

Ability of substances to cross cell membranes influenced by properties.

Relationship of drug concentrations free and bound in tissues and plasma.

Drug that is not bound to proteins, available for action and elimination.

Balance between unbound and bound drugs in plasma and tissues.

Most abundant plasma protein that binds many drugs, especially acidic ones.

Values between 0-1 indicating the degree of protein binding of a drug.

Changes in f_u change drug volume and clearance, affecting overall disposition.

Acidic drugs bind mainly to albumin, affecting their distribution volume.

Basic drugs prefer binding to albumin and lipoproteins, often with lower affinity for tissues.