True about sulfonylureas is -
Ans. is 'b' i.e., Most common side effect is hypoglycemiao Sulfonylureas are -1. First generation Tolbutamide, chlorpropamide.2. Second generation Glibenclamide (Glyburide), glipizide, gliclazide, glimpride.Sulfonylureas act byo Sulfonylurease provoke a brisk release of insulin from pancreas. They act on the so called "Sulfonylurea receptors" (SUR1) on pancreatic b-cell membrane - cause depolarization by reducing conductance of ATP sensitive K+ channels. This enhances influx of Ca+2 - degranulation. They do not cause hypoglycemia in pancreatectomized animals and type 1 diabetes (Presence of at least 30% of functional b-cells in essential for their action). A minor action reducing glucagon secretion by increasing insulin and somatostatin release has been demonstratedo Extrahepatic action# On chronic administration they sensitize the target cells (especially the liver) to the action of insulin.# On chronic administration their action on pancrease (to release insuline) declines due to down regulation of sulfonylurea receptors.# But glycemic control is maintained due to extrahepatic action.# Glimepiride exerts beneficial effects with regard to ischemic preconditioning.Sulfonyloreas cause following adverse effectso Hypoglycemia# This is commonest side effect.# More common in elderly, liver and kidney disease.# Chlorpropamide is a frequent culprit due to its long action due to its long action.# Tolbutamide carries lowest risk due to its low potency and short duration of action.# Lower incidence is also reported with glipizide, glibenclamide, glimepiride.o Hypersensitivity# Rashes, photosensitivity, purpura, transient leukopenia, rarely agranulocytosiso Adverse effects specific to particular drug# Cholorpropamide causes cholestasis, dilutional hyponatremia, intolerance to alcohol (disulfiram like reaction). Chlorpropamide causes dilutional hyponatremia by sensitising the kidney to ADH action.# Tolbutamide reduces iodine uptake by thyroid.o Sulfonylureas are not safe during pregnancy - change over to insulin. Sulfonylureas are secreted in milk - should not be given to nursing mothers. Gliclazide has an antiplatelet effect.
Chlorpropamide is 2nd generation agent
Most common side effect is hypoglycemia
Effective even after pancreactomy
Safe in pregnancy
Anti Diabetes