drug notes: sulphonylureas

Question 1

what are some examples of second generation (used now) sulphonylureas?

Answer 1

• glucazide
• glipzide
• gliepride
• gliclazide
• glibenclamide

Question 2

what do sulphonylureas act on ?

Answer 2

SUR1 receptor subunits on KATP channel

Question 3

what affects does binding of sulphonylurea to SUR1 of the KATO channel have?

Answer 3

-it closes the ATP sensitive K channel

Question 4

how does sulphynurea work?

Answer 4

stimulates pancreatic beta cells to produce insulin

• it binds to SUR1 (the extracellular subunit of the KATP)
• binding causes closure of KATP
• closer causes depolarisation of beta cell membrane which causes the voltage gated calcium channel to open
• calcium influx leads to insulin exocytosis

Question 5

do sulphonylureas still work when glucose is low?

Answer 5

yes- they are glucose independant so will secrete insulin when glucose is normal or low

Question 6

why is it dangerous that sulphonylureas are glucose independant?

Answer 6

-can lead to hypoglycaemia

Question 7

what are sulphynulureas?

Answer 7

-drugs that act directly on pancreatic beta cells to increase insulin secretion as such are termed ‘insulin secretagogues’

Question 8

side effects of sulphonylurea?

Answer 8

• increase weight

- risk of hypoglyceamia

Question 9

when are sulphonylureas used?

Answer 9

-second line to metformin when there is an issue with money (theyre so cheap!)

Question 10

should sulphonylurea be prescribed to a driver?

Answer 10

no- too much of a risk of hypo