Drug Elimination and Clearance Concepts

<p>The sum of renal clearance and nonrenal clearance (B)</p> Signup and view all the answers

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

<p>Describing drug elimination quantitatively (D)</p> Signup and view all the answers

<p>It provides a measure for adjusting dosage based on observed renal function (D)</p> Signup and view all the answers

<p>The drug is unbound to plasma proteins and not reabsorbed (C)</p> Signup and view all the answers

<p>It enhances the development of models aligned with body functions (C)</p> Signup and view all the answers

<p>The overall drug clearance in clinical practice (A)</p> Signup and view all the answers

<p>It describes drug elimination. (A)</p> Signup and view all the answers

<p>Dose divided by AUC₀-inf. (D)</p> Signup and view all the answers

<p>1 / λz. (A)</p> Signup and view all the answers

<p>It is defined as Dose / (AUC₀-inf × λz). (C)</p> Signup and view all the answers

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

<p>MAT + MRT. (A)</p> Signup and view all the answers

<p>Clearance will be the same. (A)</p> Signup and view all the answers

<p>Mean absorption time (MAT). (B)</p> Signup and view all the answers

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

<p>Reabsorption and secretion processes (A)</p> Signup and view all the answers

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

<p>A summation of filtration, reabsorption, and active secretion (B)</p> Signup and view all the answers

<p>It remains constant unless affected by severe renal impairment (D)</p> Signup and view all the answers

<p>When excretion is solely by active secretion (A)</p> Signup and view all the answers

<p>The intercept is simplified to nonrenal clearance (ClNR) (C)</p> Signup and view all the answers

<p>Excretion occurs by both filtration and secretion (C)</p> Signup and view all the answers

<p>Weak acids with a pKa of 3 are highly ionized at all urinary pH values. (C)</p> Signup and view all the answers

<p>It increases the excretion of weak acids. (C)</p> Signup and view all the answers

<p>pKa of 7.5-10.5 (D)</p> Signup and view all the answers

<p>Increased kidney blood flow. (C)</p> Signup and view all the answers

<p>It decreases reabsorption time, thereby promoting excretion. (C)</p> Signup and view all the answers

<p>Increased kidney blood flow due to diuretic therapy. (B), Alkalinization of the urine. (C)</p> Signup and view all the answers

<p>Sulfisoxazole and Sulfamethoxazole/Trimethoprim (D)</p> Signup and view all the answers

<p>Reabsorption is generally influenced by urine pH and drug ionization. (B)</p> Signup and view all the answers

<p>Greater renal clearance (D)</p> Signup and view all the answers

<p>By the slope of the cumulative drug excretion curve (C)</p> Signup and view all the answers

<p>It complicates the calculation of renal clearance (B)</p> Signup and view all the answers

<p>Cumulative drug excretion can be graphed against AUC to find clearance (C)</p> Signup and view all the answers

<p>Suggests a slower rate of drug excretion (D)</p> Signup and view all the answers

<p>It connects cumulative excretion with AUC (B)</p> Signup and view all the answers

<p>Incomplete data leads to potential errors in calculations (C)</p> Signup and view all the answers

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

A direct measure of drug elimination from the body, including plasma and highly perfused tissues.

Rate constant for elimination of a drug.

Pharmacokinetic method that determines clearance without compartments.

Area under the curve from time zero to infinity after drug administration (IV)

Average time a drug stays in the body.

Drug elimination rate matches the absorption rate, maintaining stable drug levels in the body.

Drug elimination and absorption that are consistent and maintain constant ratio regardless of dose.

Plasma and rapidly equilibrating tissues (like kidney and liver)

How much a weak acid breaks down into ions depends on the urine's pH. The effect is strongest when the drug's pKa is between 3 and 8.

A drug with a pKa of 5 will be more affected by urine pH changes than a drug with a pKa of 3. A drug with a pKa of 2 is mostly ionized regardless of urine pH.

The extent to which a weak base breaks down into ions is greatly influenced by urine pH, especially when the drug's pKa is between 7.5 and 10.5.

Drugs are eliminated by the kidneys through a combination of filtration, active secretion, and reabsorption.

This is a process where the kidneys actively pump drugs out of the bloodstream. It can be saturated, meaning it can only handle a limited amount of drug.

Reabsorption of weak acids and bases depends on urine pH and drug ionization.

Increased urine flow, caused by things like alcohol or caffeine, decreases drug reabsorption and increases excretion.

Using diuretics can increase the excretion of drugs by the kidneys.

The rate at which a drug is removed from the body by the kidneys, measured as the volume of plasma cleared of drug per unit time.

The rate at which a drug is removed from the body by mechanisms other than the kidneys (e.g., metabolism, excretion in bile).

The overall rate at which a drug is removed from the body, combining both renal and nonrenal clearance.

The proportion of the administered drug dose that is excreted unchanged in urine.

Formation of drug crystals in the renal tubules, potentially leading to kidney damage.

A way to model drug elimination using mathematical equations without needing exact information about kidney function, secretion, or reabsorption.

A marker for a patient's overall renal function, used by doctors to adjust drug dosages based on how well the kidneys are working.

When a drug is removed from the body only by filtering through the kidneys, without being reabsorbed back into the bloodstream.

The process where the kidneys filter waste products, including some drugs, from the blood.

A drug that is freely circulating in the bloodstream, not attached to proteins, which is more easily filtered by the kidneys.

The rate at which the kidneys remove a drug from the body. It's a measure of how efficiently the kidneys filter and eliminate the drug.

Clearance is determined by the slope of a curve plotting the rate of drug excretion in urine against plasma concentration. A steeper slope indicates faster excretion.

The total amount of drug excreted in urine over time. It can be related to the area under the concentration-time curve (AUC).

Renal clearance is a summation of three processes: filtration, secretion, and reabsorption. It represents the combined effect of these processes on a drug's elimination.

By plotting cumulative drug excretion against AUC, we can determine renal clearance from the slope of the resulting curve.

ClR is determined by measuring the slope and intercept of a graph plotting drug concentration in urine against creatinine clearance (CrCl).

Creatinine Clearance: A measure of kidney function that estimates the GFR. It reflects the rate at which creatinine is cleared from the blood.

Missing data points can make it challenging to accurately calculate cumulative excretion and therefore renal clearance.

The intercept in the ClR formula reflects the contribution of reabsorption and secretion to the overall clearance.

Using graphs to visualize and analyze the relationship between drug excretion and plasma concentration to determine renal clearance.

A steeper slope on a curve indicates a higher rate of drug excretion, meaning the drug is being eliminated from the body more quickly.

A shallower slope on a curve indicates a slower rate of drug excretion, meaning the drug is being eliminated from the body more slowly.

Renal clearance helps predict how long a drug will stay in the body and how efficiently it will be eliminated, influencing dosing strategies.