Pharmacokinetics: Elimination Rate and Distribution

Play an AI-generated podcast conversation about this lesson

What does the formula T1/2 life CL = rate of elimination/concentration Vd= amount of drug in the body/Total conc in plasma represent?

The calculation of bioavailability of a drug

The fraction of the administered dose of a drug that reaches the systemic circulation

The relationship between the volume of distribution and the total concentration of a drug in plasma (correct)

The rate of elimination of a drug from the body

What is the process called when a drug administered into the body has some of its proportion carried away in the portal system to the liver before reaching the target site?

First pass metabolism (correct)

Systemic circulation

Pharmacological effect

Bioavailability

What is the main factor that determines how easily a non-ionized drug can diffuse across cell membranes?

The drug's ionic state

The drug's capillary permeability

The drug's lipid solubility (correct)

The drug's ability to bind to plasma proteins

What is the term for the fraction of the administered dose of a drug that reaches the systemic circulation in a chemically unchanged state?

Bioavailability Signup and view all the answers

What is the time taken for 50% of a given concentration of a drug to be eliminated?

Half-life (t1/2) Signup and view all the answers

What is the term for the movement of a drug from the blood to the interstitial or extracellular fluid?

Distribution Signup and view all the answers

What are the three main compartments that a drug can be distributed into in the body?

Intravascular, interstitial, and intracellular Signup and view all the answers

What is the route of administration that has an absolute bioavailability of 1 (F=1 or 100% bioavailable)?

Intravenous route Signup and view all the answers

What is the formula for calculating the bioavailability of a drug?

B.A = AUC of a given route/AUC of I.V Signup and view all the answers

Which of the following is NOT a determinant of drug distribution?

Age of the patient Signup and view all the answers

What is the term for the form of a drug that is bound to plasma proteins and cannot elicit its action?

Bound form Signup and view all the answers

Which organ receives the highest blood flow and therefore has a higher distribution of drugs?

Brain Signup and view all the answers

What type of metabolism do drugs like verapamil, lidocaine, and propranolol undergo?

Pre-systemic or first-pass metabolism Signup and view all the answers

What is the purpose of metabolic reactions in the liver?

To convert the drug into a more polar chemical that can be easily excreted Signup and view all the answers

What is the phase I reaction also known as?

Functionalization Signup and view all the answers

Where are cytochrome P450 systems located?

Within the endoplasmic reticulum of hepatocytes Signup and view all the answers

What is the result of enzyme induction in phase I reactions?

Drug interactions Signup and view all the answers

What are the types of phase I reactions?

Hydrolysis, oxidation, reduction, demethylation Signup and view all the answers

What happens when free forms of a drug are reduced or excreted?

Bound forms gradually become unbound and begin to elicit an action Signup and view all the answers

What is the apparent volume of distribution (Vd) equivalent to?

The dose of the drug divided by the concentration in the blood Signup and view all the answers

What affects the rate of blood flow to different tissues?

The varying rates of blood flow to different tissues Signup and view all the answers

What is the primary location where drug metabolism occurs?

The liver Signup and view all the answers

What is the result of an increase in the volume of distribution (Vd) on the half-life (t1/2) of a drug?

The half-life increases Signup and view all the answers

What happens to a drug if it is sufficiently polar after Phase I?

It is directly excreted Signup and view all the answers

What type of conjugation reaction occurs with sulfuric acid?

Sulfuric conjugation Signup and view all the answers

What is a characteristic of polar metabolites produced in Phase II?

They are not reabsorbed by the kidney Signup and view all the answers

What is an example of a pro-drug?

Enalapril Signup and view all the answers

What is a factor that influences biotransformation?

All of the above Signup and view all the answers

What is an example of an enzyme inducer?

Carbamazepine Signup and view all the answers