Antidiabetic drugs Flashcards
Which drugs are used to treat DM type 2? What do they do?
Biguanide - Metformin - Reduces hepatic glucose production, acts peripherally to increase glucose uptake, mainly into fat and muscle tissue. Rarely causes hypoglycaemia ( no insulin release) and doesn’t lead to weight gain.
Sulphonylureas - Glibenclamide, Glipizide, Gliclazide, Glimepiride, Tolbutamide. - Stimulate insulin release from the pancrease, so patient must have some residual beta-cell function. Might encourage weight gain.
Prandial glucose regulators - Repaglinide, Nateglinide, Meglitinide - very short acting insulin release stimulators, taken shortly before meals. Low risk of hypoglycaemia.
Alpha Glucosidase inhibitor - Acarbose - inhibits intestinal alpha glucosidases, delays digestion of starch and sucrose. May cause flatulance.
Glitazones (thiazolidinediones) - Pioglitazone - Increase sensitivity to insulin by increasing transcription of insulin sensitivity genes. Protects the cells in pancreas. Can be given alone or with metformin or sulphonylureas.
Incretin mimetics / GLP-1 analogues - Exenetide, Liraglutide, Lixisenatide, Dulaglutide - Increase insulin when needed, reduce hepatic gluconeogenesis when not needed. Reduce rate of digestion and gastric emptying, may reduce appetite.
DPP-4 inhibitors (Gliptins) - Sitagliptin, Vildagliptin …gliptin - blocks the action of DDP-4, an enzyme that destroys incretin.
SGLT2 inhibitors - Dapagliflozin, Canagliflozin, Empagliflozin - Lead to increased urinary excretion of glucose, reducing blood levels. Depend on kidney function. May lead to urinary tract infections.
What type of insulin are most diabetic treated with?
Human insulin
How is the rate of insulin absorption controlled?
By increasing the size of the particles, or complexing it with zinc or protamine.
What are the types of short-acting insulins?
Soluble insulin - onset 30 mins, activity 2-4hr, subsides by 8hr, IV in hypoglycaemic emergencies by effects only last 30 mins by this route
Insulin lispro, insulin aspart - insulin analoges, faster onset and shorter action time (no dimer formation)
What are the types of intermediate acting insulins?
isophane insulin - protamine and insulin
What are the types of long actin insulin?
Protamine Zinc - complexed with both protamine and zinc, not used often as bind soluble insulin.
Insulin zinc suspension - poorly soluble zinc crystals, duration up to 35 hr
Insulin glargine - long, peakless activity (11-12hr)
What are the newer anti-diabetic drugs and how do they work?
1) Increasing GLP-1 levels, either by the administration of an analogue (glucagon-like peptide-1, GLP-1 mimetics, e.g. exenatide, liraglutide) or
2) inhibiting its breakdown (dipeptidyl peptidase-4 ,DPP-4 inhibitors - the gliptins Vildagliptin, sitagliptin), is therefore the target of two recent classes of drug.
How is exenatide administered?
Subcutaneous injection within 60 minutes before the morning and evening meals. It should not be given after a meal.
What is the advantage of liraglutide over exenatide?
Liraglutide only need to be given once a day
When are Glitazones / thiazolidinediones contra-indicated?
Heart failure
