Pharmacology: Sulphonylureas Flashcards
what are the 2nd generation sulphonylureas that are used today
gliclazide, glipizide, glimepiride, glibenclamide
what cells do sulphonylureas act on
pancreatic beta cells
what part of the pancreatic beta cell do sulphonylureas bind to
SUR1 protein
what effect does sulphonylurea binding in pancreatic beta cells have to ATP sensitive K channels
closes them
describe how sulphonylurea binding acts to secrete insulin
closes Katp channels, depolarises membrane, triggers voltage gated Ca2+ channels, Ca2+ influx results in insulin exocytosis
describe the relation between sulphonylurea and glucose
glucose independent, insulin secreted when not needed(when glucose low or normal)
what result do sulphonylureas have on insulin
increase secretion
what type of drug are sulphonylureas
insulin secretagogues
what does sulphonylureas being glucose independent result in
hypoglycaemia
how potent are sulphonylureas
relatively potent, about same as metformin
what effect do sulphonylureas have on the weight of a patient
increase weight, by 1-2kg on average
what is the most commonly used sulphonylurea used in the UK, and at what dose
gliclazide, 40-80mg od, little benefit in going >80mg but max dose is 160
what are the possible side effects of sulphonylureas
hypoglycaemia, weight gain
what risk factors increase risk for hypoglycaemia
increased age, diabetes duration, creatinine, lower HbA1c(esp <50mmo/mol)
describe why sulphonylureas result in weight gain
insulin conc. increase, insulin is anabolic = increased carb storage.
insulin increases appetite
