General pharmacology

Question 1

What is the difference between pharmokinetics and pharmodynamics?

Answer 1

pharmokinetics is the effect of the body on the drug i

pharmodynamics is the effect of the drug on the body .

Question 2

What are the features of a lipid soluble drug?

Answer 2

Easily absorbed
Widely distributed
Longer mechanism of action ( deposited in fat)

Question 3

What is biotransformation?

Answer 3

Modification of a chemical (drug metabolism is a type of biotransformation)

Question 4

What are the phases of biotransformation in the liver?

Answer 4

phase 1 - metabolism phase 2 - conjugation

Question 5

What is the purposes of drug metabolism?

Answer 5

To make drugs more water soluble for excretion by making them more polar

Question 6

What enzyme is important in phase 1 drug metabolism?

Answer 6

cytochrome p450

Question 7

What do “enzyme inducing” anti-epileptics induce?

Answer 7

Increased activity of cytochrome p450 proteins and therefore increased phase 1 metabolism of drugs and in turn increased excretion

Question 8

Where does phase 2 biotransformation occur?

Answer 8

Liver cytosol

Question 9

What is the contraceptive pill conjugated with in drug metabolism?

Answer 9

sulphate

Question 10

What are morphine and paracetamol conjugated with in drug metabolism?

Answer 10

glucuronate

Question 11

Define volume of distribution

Answer 11

total volume of drug in body : volume in blood

Question 12

What does a large volume of distribution signify?

Answer 12

most of the drug is in tissues

i.e. lipophilic drugs

Question 13

Which important drugs can’t cross the placenta?

Answer 13

insulin and heparin

Question 14

Which important drugs can’t enter breastmilk?

Answer 14

warfarin, aminoglycosides

Question 15

Which drugs lead to folate deficiency?

Answer 15

methotrexate and trimethoprim

Question 16

How do certain drugs lead to folate deficiency?

Answer 16

methotrexate and trimethoprim inhibit dihydrofolate reductase which convertes dihydrofolate to tetrahydrofolate which is used in cell proliferation and growth

Question 17

What enzyme does methotrexate inhibit? And what other drug does this?

Answer 17

dihydrofolate reductase

trimethoprim

Question 18

What is the consequence of dihyfrofolate reductase inhibition?

Answer 18

dihydrofolate not converted to tetrahydrofolate - leads to folate deficiency and megoblastic anaemia, reduced/abnormal cell growth and proliferation