Pharmacology: PKPD

Pharmacokinetics is

• what the drug does to the body.

• related to efficacy.

• related to elimination half-life.

• what the body does to the drug.

Regarding absorption of drugs:

• It happens best when the drug molecule is charged/polarised

• Diffusion happens following concentration gradient of drug

• Receptor-mediated transport follows electrochemical gradient of drug

• Large drug molecules are absorbed via endocytosis

Regarding distribution of drugs in the body:

• A nonpolar drug molecule would mostly stay in the plasma compartment

• A polar drug molecule is always bound to plasma protein

• Plasma protein binding will influence drug level at its site of action

• A large volume of distribution lead to a "drug reservoir" effect

Where does drug metabolism occur?

(Circle your answer -- there can be MORE than 1)

In first-order kinetics, there is a constant [_____] of drug molecules being eliminated, whilst drugs that follow zero-order kinetics will have a constant [_____] of their molecules eliminated.

(separate your answer with a slash "/" mark)

Warfarin is a weak acid drug, pKa 5.0. Which part of gastrointestinal tract that most absorb warfarin?

• Stomach

• Mouth

• Duodenum

• Ileum

• Jejunum

Drug X has an apparent of volume of distribution of 50 L/kg. Which of the following best describes the property of drug X?

• Low lipophillicity

• Low plasma protein binding

• Rapid onset of action

• Limited across blood brain barrier

• Excreted in urine with unchanged form

A pharmacology student asks the instructor what the accurate description of a drug agonist is. What is the instructor's best response?

• A drug that reacts with the receptor site on a cell preventing a reaction with another chemical on a different receptor site.

• A drug that interferes with the enzyme systems and act as catalyst for different chemical reactions.

• A drug that interacts directly with receptor sites to cause the same activity that a natural chemical would cause at the site.

• A drug reacts with receptor site to block normal stimulation, producing no effect.

What factor influences drug absorption?

• Kidney function

• Route of administration

• Liver function

• Cardiovascular function

The patient is taking low-dose aspirin daily for his heart. The nurse knows only a portion of the medication taken actually reaches the tissue due to what process?

• Distribution

• First-pass effect

• Reduced absorption

• Gastrointestinal circulation