pharmacokinetics 1

Question 1

Which route of drug administration involves “first pass” metabolism

Answer 1

Oral
drug is absorbed in the small intestine and is transported by the hepatic portal vein (HPV) directly to the liver where it’s metabolised before entering the systemic circulation

Question 2

Clearance is the measure of ….

Answer 2

The rate of elimination of the drug from the body relative to the plasma concentration of the drug.

Question 3

Oral administration

Answer 3

Administration of drug through the mouth, absorbed through the gastrointestinal tract.

Question 4

Intravenous (IV) administration

Answer 4

Direct injection of drugs into a vein for rapid systemic delivery

Question 5

Intramuscular (IM) administration

Answer 5

Injection of drugs into muscle tissue for systemic absorption

Question 6

Subcutaneous administration

Answer 6

Injection of drugs into the layer of tissue just beneath the skin

Question 7

Topical administration

Answer 7

Application of drugs into the skin or mucous membranes

Question 8

Inhalation administration

Answer 8

Delivery of drugs directly to the lungs via inhalation

Question 9

Epidural administration

Answer 9

Injection of medication into the epidural space surrounding the spinal cord and dura mater, typically in the lumbar or thoracic region

Question 10

Intrathecal administration

Answer 10

Direct injection of medication into the subarachnoid space surrounding the spinal cord and cerebrospinal fluid

Question 11

Intraperitoneal administration

Answer 11

Introduction of medication into the peritoneal cavity, which contains organs such as the stomach, liver, and intestines, via injection or infusion

Question 12

Factors that affect drug entry into compartments

Answer 12

1. depends on lipid solubility
2. depends on extent of first pass metabolism
3. depend on presence of specific carriers
4. depends on surface area available for absorption

Question 13

Patient with below average clearance

Answer 13

Drug will not be removed quite as quickly from the body. so it will tend to accumulate so the “steady state” plasma concentration will tend to be higher.

Question 14

Bioavailability

Answer 14

The fraction of a drug administrated via a specific route that reaches systemic circulation in its unchanged form. Thereby exerting it’s pharmacological effects.

Question 15

Half-life (T0.5)

Answer 15

The time required for the concentration of a drug in the bloodstream to decrease by half its original value. reflecting the rate of elimination.

Question 16

Steady state

Answer 16

Steady state occurs when the rate of drug administration equals the rate of drug elimination, resulting in constant drug concentration in the bloodstream over time

Question 17

First order kinetics

Answer 17

Describes drug elimination where the rate of elimination is proportional to the drug concentration in the bloodstream, resulting in exponential decay.

Question 18

Zero order kinetics

Answer 18

Drug elimination where the rate of elimination remains constant over time, independent of the drug concentration in the bloodstream.

Question 19

Volume of distribution

Answer 19

Represents the hypothetical volume of fluid into which a drug appears to be uniformly distributed at a concentration equivalent to its plasma concentration

Question 20

Large “volume of distribution” indicates…

Answer 20

The drug is probably very lipid soluble and can enter many tissues in the body