Pharmacodynamics continued

Question 1

What is the name of the enzyme that breaks down acetylcholine? If a chemical (like nerve gas) disabled that enzyme, would that chemical be an agonist, or an antagonist? Explain.

Answer 1

enzyme = acetylcholinesterase
it would be an agonist, because it is preventing breakdown of acetylcholine, thus prolonging its effects

Question 2

Which would have a greater maximum effect? Tylenol or Oxycontin?

Answer 2

oxycontin

Question 3

Drug A has an ED50 of 2 mg and an LD50 of 4 mg. Drug B has an ED50 of 2 mg and an LD50 of 10 mg. Which drug is safer? Explain.

Answer 3

Drug B is safer, because the ratio of its lethal dose (10mg) to its effective dose (2mg) is higher (5) than that of Drug A (2)

Question 4

With repeated exposure to an agonist drug, the postsynaptic cell decreases its receptors (this is called cellular tolerance). Why do you think it does that?

Answer 4

because that will protect it from getting bombarded with ligands (drug/neurotransmitter), and allow it to approximate normal conditions

Question 5

What are some reasons that you can think of that is it necessary to study placebo effects?

Answer 5

they have to be separated from drug effects to determine drug efficacy during drug development
they could potentially be manipulated to enhance standard treatment