Pro-drugs

Question 1

Give 4 examples of Pro-drugs:

Answer 1

L-DOPA
Codeine
Sulfasalazine
Cyclophosphamide

Question 2

What is L-DOPA used in the treatment of?

Answer 2

Parkinsons Disease

Question 3

How does L-DOPA work?

Answer 3

crosses BBB and increased dopamine levels

Question 4

Why are high doses of L-DOPA required?

Answer 4

DOPA decarboxylase is present in the body and metabolises L-DOPA

Question 5

What drug can be given to prevent DOPA Decarboxylase metabolising L-DOPA?

Answer 5

Carbidopa

Question 6

What is codeine used to treat?

Answer 6

pain

Question 7

how does codeine act as a prodrug?

Answer 7

metabolised in the liver by the CYP2D6 enzyme into morphine

Question 8

What are the 2 clinical uses of Sulfasalazine?

Answer 8

• anti-inflammatory for bowel disease

- rheumatoid arthiritis

Question 9

How does Sulfasalazine act as a prodrug?

Answer 9

metabolised in the gut to produce

Mesalazine and Sulfapyroxidine

Question 10

What is Cyclophosphamide used in the treatment of?

Answer 10

Cancers and autoimmune disorders

potent immunosuppressant drug

Question 11

What is Cyclophosphamide metabolised by?

Answer 11

The cytochrome P450 in the liver

Question 12

What is the product of Cyclophosphamide metabolism?

Answer 12

Carbinolamine

Question 13

What is the role of Carbinolamine?

Answer 13

Alkylates G residues on DNA, prevents DNA uncoiling

Question 14

What is Acyclovir?

Answer 14

anti-viral guanosine analogue

Question 15

What is Acyclovir used in the treatment of?

Answer 15

HSV

herpes simplex virus

Question 16

What does Thymidine Kinase (enzyme essential for DNA synthesis) do to acyclovir?

Answer 16

Converts it from monophosphate to di/tri-phosphate

Question 17

How does Acyclovir triphosphate (AcTP) result in DNA chain termination?

Answer 17

Competitively inhibits viral DNA polymerase by acting as a dGTP analogue