Drugs are Poisons

Question 1

Atropine effect

Answer 1

Blocks muscarinic receptors in the brain

Question 2

Physostigmine

Answer 2

ACh esterase inhibitor

Question 3

Digitalis mode of action:
1)
2)
3)
4)

Answer 3

1) Inhibits Na+/K+ ATPase
2) Increases intracellular Na+
3) Decreases Ca2+ extrusion
4) Increases heart contractile force

Question 4

Digitalis drug type

Answer 4

Cardiac glycoside

Question 5

Digitalis overdose effects

Answer 5

Causes cardiac arrhythmias

Exacerbated by low K+

Question 6

Digitalis overdose treatment

Answer 6

K+

Question 7

Paracetamol effect

Answer 7

Analgesic

Question 8

Paracetamol mode of action

Answer 8

Metabolite in brain might activate CB1 cannabinoid receptor

Question 9

Paracetamol off-target effects

Answer 9

Depletes glutathione in liver

This leads to oxidative damage of liver cells, necrosis

Question 10

Size of therapeutic window for paracetamol

Answer 10

Large.

Good/bad mechanisms different

Question 11

Size of therapeutic window for digitalis

Answer 11

Small

Good/bad mechanisms are the same

Question 12

Terfenadine

Answer 12

Precursor to fexofenadine

Question 13

Enzyme that converts terfenadine to fexofenadine

Answer 13

CYP3A4

Question 14

Source of dihydrobergamottin

Answer 14

Grapefruit

Question 15

Compound in grapefruit that inhibits CYP3A4 action

Answer 15

Dihydrobergamottin

Question 16

Effects of dihydrobergamottin on ingested terfenadine:
1)
2)

Answer 16

1) Terfenadine is not converted into fexofenadine in the liver by CYP3A4
2) Terfenadine becomes bioavailable, causes irregular heartbeat

Question 17

Dihydrobergamottin

Answer 17

Irreversible inhibitor of CYP3A4 in liver

Question 18

CYP3A4

Answer 18

Liver enzyme, converts terfenadine to fexofenadine (among other things)