Chapter 3- Pharmacokinetics

Question 1

Pharmacokinetics

Answer 1

Study of drug movement throughout the body

- what the BODY does to medication after it is administered

Question 2

First-pass effect

Answer 2

Drugs absorbed from the stomach and small intestine must first travel to the liver. Here they are inactivated before they ever reach their target organs, this is what is called the____.

Question 3

Drug Ionization increases or decrease permeability across the plasma membrane?

Answer 3

decreases

- non-ionized particles pass more easily

Question 4

Drug-protein complexes

Answer 4

Drugs bind reversibly to plasma proteins

• complexes are too large to cross the plasma membrane
• these medications will stay in circulation until they are released or displaced from the drug-protein complex

Question 5

Prodrugs

Answer 5

Medications that require metabolism to produce their therapeutic actions

Question 6

Hepatic microsomal enzyme system

Answer 6

Most metabolism in the liver is accomplished via this
Isozymes of CYP450
How the body metabolizes drugs

Question 7

Enzyme induction

Answer 7

Increases metabolic activity in the liver (thereby increasing inactivation of the drug)

Question 8

Enterohepatic recirculation

Answer 8

Some substances in the bile are reabsorbed (stored in the GB) and circulated back into the liver by this method
- drugs or their metabolites (byproducts/byproduct of the drug as a consequence of passing through the body) may participate in this process and recirculate numerous times with bile (therefore producing an extended/prolonged effect)

Question 9

Plasma half-life

Answer 9

Most common description of a drug’s duration of action

- the length of time required for the plasma concentration of a drug to decrease by one half after administration

Question 10

Loading dose

Answer 10

Higher amount of drug, often given only once or twice, that is administered to “prime” he bloodstream with a sufficient level to quickly induce a therapeutic response

Question 11

Maintenance dose

Answer 11

Intermittent doses given to keep the plasma drug concentration within the therapeutic range

Question 12

What type of patient is a nurse most likely anticipating an alteration in drug metabolism?

Answer 12

An infant
- infants do not develop a mature microsomal enzyme system until they are a year old, and therefore do not metabolize drugs very efficiently