Drug enzyme targets

Question 1

What are the 3 types of AChE inhibitors (anti-cholinesterases)?

Answer 1

short-acting
medium duration
irreversible

Question 2

Give an example of a short-acting AChE inhibitor?

Answer 2

Edrophonium

Question 3

What is edrophonium used for?

Answer 3

diagnostic test for myasthenia gravis

Question 4

What is Myasthenia Gravis?

Answer 4

body’s own immune system destroys ACh receptors on cells, resulting in muscle weakness

Question 5

Give 3 examples of medium duration anticholinesterases?

Answer 5

Pyridostigmine
Neostigmine
Physostigmine

Question 6

What are 2 advantages of pyridostigmine over Neostigmine?

Answer 6

• Better absorbed

- Longer lasting

Question 7

What is Pyridostigmine used for?

Answer 7

treatment for Myasthenia Gravis

Question 8

What is Physostigmine used for ?

Answer 8

used in eye drops to treat glaucoma

Question 9

Give 2 examples of irreversible anticholinesterases?

Answer 9

Dyflos and Ecothiophate

Question 10

What are the 2 most common ACE inhibitors?

Answer 10

Enalaprilat

Captopril

Question 11

How is Enalaprilat a prodrug?

Answer 11

Converted from Enalapril in the liver to Enalaprilat

Question 12

What is the function of Angiotensin II?

Answer 12

Potent vasoconstrictor

Question 13

What are the clinical uses of ACE inhibitors?

Answer 13

Hypertension

Congestive Heart failure

Question 14

What is the common drug group used to target the COX-1 and COX-2 enzymes?

Answer 14

NSAIDs

Non Steroidal Anti-Inflammatory Drugs

Question 15

How do NSAIDs exhibit their anti-inflammatory effect?

Answer 15

Decrease prostaglandin E2 and Prostacyclin production which reduced vasodilation

Question 16

How do NSAIDs exhibit their anti-pyretic effect?

Answer 16

Prevent IL-1 releasing prostaglandins in CNS that increase the hypothalamic set point for temperature

Question 17

What sort of pain are NSAIDs ideal for managing?

Answer 17

Inflammation and tissue damage

Question 18

How do NSAIDs exhibit their analgesic effect?

Answer 18

decrease the production of prostaglandins that sensitise nociceptors

Question 19

what are nociceptors?

Answer 19

sensory neurones that respond to damaging stimuli

Question 20

What are some of the unwanted effects of NSAIDs?

Answer 20

GI disturbances
skin reactions
CV side effects

Question 21

Give an example of an unwanted side effect of a NSAID

Answer 21

Aspirin- anti platelet action

other NSAIDs don’t

Question 22

How do DPP IV inhibitors work?

Answer 22

prevent the DPP IV enzyme breaking down incretins, thereby increasing incretin levels and lowering blood glucose

Question 23

In what 2 ways do DPP IV inhibitors lower blood glucose?

Answer 23

Inhibit glucagon release

Trigger insulin release

Question 24

Give 2 examples of DPP IV inhibitors?

Answer 24

Sitagliptin

Ildagliptin

Question 25

What are the clinical uses for DPP IV inhibitors?

Answer 25

Obesity | Diabetes

Question 26

What are the 3 main examples of irreversible MAO inhibitors?

Answer 26

Phenelzine Tranylcypromine Iproniazid

Question 27

Which molecular form of MAO is the preferred target for MAO inhibitors?

Answer 27

MAO-A

Question 28

What does MAO-A have a substrate preference for?

Answer 28

serotonin (5-HT)

Question 29

What does MAO-B have a substrate preference for?

Answer 29

Dopamine and phenylethylamine

Question 30

What drug selectively inhibits MAO-B preventing the breakdown of dopamine?

Answer 30

selegiline (used to treat Parkinsons)

Question 31

What are the clinical uses of MAO inhibitors?

Answer 31

Depression and Anxiety

Question 32

Give 2 examples of PDE V inhibtors?

Answer 32

Sildenafil (viagra) | Tadalafil (longer acting)

Question 33

How is PDE V used to treat Erectile dysfunction?

Answer 33

prevents the cGMP being converted to an inactive product | Instead it activates protein kinase G resulting in vasodilation and improved blood flow

Question 34

What other clinical use can PDE V inhibitors be applied to?

Answer 34

Pulmonary Hypertension

Question 35

Give an example of an XO inhibitor?

Answer 35

Allopurinol

Question 36

How does Allopurinol decrease uric acid synthesis?

Answer 36

Converted to Alloxanthine (by XO) | Which is a non- competitive inhibitor of XO (remains in tissues for long time)

Question 37

What is the clinical use of XO inhibitors?

Answer 37

Gout

Question 38

What is Gout?

Answer 38

a metabolic disease that causes urate crystals to be deposited into tissues

Question 39

What is chloroquine?

Answer 39

Anti-malarial Haem Polymerase Inhibitor

Question 40

What does Haem Polymerase do?

Answer 40

converts FP IX to non-toxic haemozoin

Question 41

in what 2 ways do haem polymerase inhibitors cause toxicity?

Answer 41

1. Cause build up of FP IX | 2. Form chloroquine-haem complexes that generate free radicals