Pharm Exam 1 --> Basic Principles part 2

Question 1

Difference between Zero order and 1st order elimination

Answer 1

Zero order: Given amount of drug is eliminated per unit of time. It is constant. Ex: 1 gram of alcohol per hour, always

1st order: Amount eliminated is dependent upon the amount of drug in the plasma at any given time. Constant fraction (50%)

Question 2

What is the steady-state concentration

Answer 2

After administration of multiple therapeutic dosages of a drug at regular time intervals, a plateau level of drug accumulates.
- Plateau represents a rate of drug administration that is equal to the rate of drug elimination

Question 3

How is the steady-state concentration achieved?

Answer 3

At a regular dosing frequency, the drug does not accumulate and a steady state or equilibrium is eventually reached.

Question 4

What are the most common binding that drugs use to interact with receptors?

Answer 4

Hydrogen binding and ionic binding are the most common

Question 5

T or F, The affinity of a drug for a particular receptor and the type of binding is not directly related to the drug’s chemical structure

Answer 5

False, It is intimately related

Question 6

Describe the concept of “induced fit” for a drug molecule with a receptor

Answer 6

1. Drug causes conformation change in the protein
2. Brings other amino acid residues in close association with the drug
3. Sometimes known as the “lock and key” mechanism of drug binding

Question 7

T or F, Many receptors are components of the cell membrane structure

Answer 7

True

Question 8

Describe Receptors ability to communicate with the cell

Answer 8

1. These proteins facilitate communication between the two sides of the membrane
2. They recognize selected molecules at the external surface and transmit information to the inside of the cell

Question 9

Define the term ligand

Answer 9

• Molecules that bind to the receptor protein or receptor glycoprotein
• May be hormones, neurotransmitters, growth factors or drug molecules

Question 10

Define the term “cell signaling”

Answer 10

When a ligand binds to a specific area of the receptor protein on the outer surface of the cell, or within the cell membrane, a conformational change occurs in the receptor-protein molecule which is transmitted to the inner surface of the cell membrane

Question 11

Describe 4 different cell signaling substances in the body

Answer 11

1. Hormones such as insulin are legends which induce cell signals
2. Neurotransmitters such as norepinephrine are cell signaling ligands
3. Growth factors such as growth hormone are cell signaling ligands
4. Drugs

Question 12

Describe 4 examples of cellular responses that occur following cell signaling

Answer 12

1. Ion channel opening or closing
2. Formation of intracellular second messenger
3. Alterations in gene expression of the cell
4. Initiation or alterations in cell growth and differentiation

Question 13

Define drug potency

Answer 13

Amount of drug necessary to produce the effect

- think DOSE of the drug

Question 14

Define drug efficacy

Answer 14

Efficacy is the degree of maximum intensity of the effect

- think EFFECT of the drug

Question 15

Differentiate between an agonist and an antagonist:

Answer 15

Both compete for the same receptor site

• Agonist
  
  • Drug that is able to bind a receptor and produce an effect
• Antagonist
  
  • Drug that binds to same receptor as an agonist, but is unable to activate the receptor. NO EFFECT

Question 16

Differentiate between competitive versus non-competitive antagonists

Answer 16

Competitive: competes with agonist for same receptor site and blocks receptor

Non-Competitive: Binds irreversibly = cannot be displaced.

Question 17

Differentiate between pharmacologic antagonism with physiologic antagonism

Answer 17

Physiologic antagonist:

• Activates pathways that oppose the action of the agonist
• Agonist and antagonist act independently on 2 different receptors

Pharmacologic antagonist:

• Both agonist and antagonist compete for the same receptor site
• Antagonist binds FIRST
• Prevents agonist from producing effect
• Either competitive or non-competitive

Question 18

What is the therapeutic window for drug effects?

Answer 18

The range of the doses of a drug that elicits a therapeutic response, without unacceptable side effects (toxicity) in a population of people

Question 19

T or F, Blood plasma levels of a drug with a small therapeutic window must be monitored closely to maintain effective dosing without exceeding the level that could produce toxicity

Answer 19

True