SM_187b: Diabetes Pharmacology Flashcards
Diabetes is a group of metabolic disorders resulting in ___
Diabetes is a group of metabolic disorders resulting in hyperglycemia
Prolonged hyperglycemia in diabetes results in ____, ____, ____, and ____
Prolonged hyperglycemia in diabetes results in cardiovascular disease, nephropathy, retinopathy, and neuropathy
____ is the key to alleviated symptoms and improving outcomes in diabetes mellitus
Control of blood glucose is the key to alleviated symptoms and improving outcomes in diabetes mellitus
Proinsulin is converted to insulin via ____
Proinsulin is converted to insulin via cleavage of C peptide
___ is the primary stimulus for insulin secretion
Rise in blood glucose is the primary stimulus for insulin secretion
Insulin receptor is a ____
Insulin receptor is a receptor tyrosine kinase
Describe the mechanism of action of the insulin receptor
Insulin receptor mechanism of action
- Insulin binds to insulin receptor
- Tyrosine phosphorylation of substrates activates downstream signaling
- Activation of PI3K-AKT pathway -> increased glycogen synthase, translocation of glucose transporters to membrane
- Signalging through RAS-MAPK pathway results in proliferation
T1DM is when ___ and there is an ___
T1DM is when insulin is lacking and there is an absolute requirement for insulin replacement
T2DM is when ____ due to ____
T2DM is when insulin is insufficient due to inadequate secretion or target tissue resistance
(other treatments may be able to stimulate the secretion of sufficient insulin)
Insulin needs vary throughout the day, mainly due to ___
Insulin needs vary throughout the day, mainly due to blood glucose increases after meals
____, ____, ____, and ____ are short-acting insulins
Regular insulin, lispro, aspart, and glulisine are short-acting insulins
Lispro, aspart, and glulisine insulins have ____ onset than regular insulin because they aggregate less
Lispro, aspart, and glulisine insulins have faster onset than regular insulin because they aggregate less
- Taken just before meal, activity lasts for period of meal digestion
- Aspart and glulisine insulins are used as pumps for continuous subcutaneous insulin infusion
____, ____, and ____ are longer acting insulins
- NPH insulin: protamine slows absorption
- Glargine: aggregation results in slower absorption, peakless
- Detemir: aggregates and binds to albumin, peakless
NPH insulin, glargine, and detemir are longer acting insulins
Basal / bolus insulin regimen involves ____
Basal / bolus insulin regimen involves glargine or detemir before breakfast or at bedtime, with preprandial injections of short acting insulin
Split-mixed insulin regimen involves ____
Split-mixed insulin regimen involves pre-breakfast and pre-supper injection of a mixture of short- and long-acting insulins
Insulin pump is used for ____ to provide ____ with ____
Insulin pump is used for continuous subcutaneous insulin infusion to provide a continuous basal rate with mealtime bolus injections based on size and nature of meals
- Complications: abscesses, cellulitis, pump failures
Describe limitations to and alternatives for insulin administration methods
Limitations to and alternatives for insulin administration methods
- Limitations: amount / type of food influence insulin requirement, r egional blood flow affected by exercise / temperature / smoking, and counterregulatory hormones / injury / infection / other drugs affect insulin requirement
- Islet cell autotransplantation: infusion of own pancreatic islet cells into portal vein in liver
- Generation of induced pluripotent stem cell derived beta cells for autologous replacement therapy
____ and ____ are major side effects of insulin
Hypoglycemia and weight gain are major side effects of insulin
- Risk higher in kids
Treatment of insulin-induced hypoglycemia is ____
Treatment of insulin-induced hypoglycemia is glucose
- Glucagon: acts through GPCR and cAMP, increases hepatic glucose production
- Diazoxide (thiazide): no diuretics, interacts with beta cell K channel, decreases insulin secretion
Describe mechanisms of therapeutic effects of agents for type 2 diabetes
Mechanisms of therapeutic effects of agents for type 2 diabetes
- Increase insulin secretion
- Affect glucose metabolism directly
- Promote insulin action
- Decrease glucose absorption
- Increase glucose excretion
Sulfonylureas (glyburide) ____
Sulfonylureas (glyburide) increase secretion of insulin from pancreatic beta cells
Glyburide is a ____
Glyburide is a sulfonylurea
Sulfonylureas (glyburide) bind to ___, ____, and ____
Sulfonylureas (glyburide) bind to the sulfonylurea, block the KATP channel, and depolarize the beta cell
Increase secretion of insulin
Describe pharmacokinetics of sulfonylureas
Sulfonylurea pharmacokinetics
- Rapidly absorbed after oral administration
- Absorption can be reduced by food and hyperglycemia
- Highly protein bound (> 90%)
- Plasma half life of 3-5 hour but 24 hour duration of hypoglycemic action
- Hepatic metabolism (CYP2C9)
- Renal excretion
Describe types of sulfonylureas
Sulfonylureas
- First generation (e.g. chlorpropamide, tolbutamide): rarely used
- Second generation (e.g. glyburide): more potent and fewer drug interactions
____ is the main adverse effect of sulfonylureas
Hypoglycemia is the main adverse effect of sulfonylureas
- Weight gain, interference with alcohol metabolism, possible adverse cardiovascular effects
Describe drug interactions of sulfonylureas
Sulfonylurea drug interactions
- Competition for plasma protein binding (especially sulfonamides) can increase [free sulfonylurea]
- Hypoglycemic effect can be decreased by ethanol
Repaglinide is a ___
Repaglinide is a meglitinide
Meglitinides (repaglinide) act on ____ and have some overlap in binding sites with ____
Meglitinides (repaglinide) act on beta cell K channels and have some overlap in binding sites with sulfonylureas
Describe the pharmacokinetics of meglitinides (repaglinide)
Meglitinides (repaglinide) pharmacokinetics
- Very rapid onset with oral administration
- Stimulate insulin over period of meal digestion
- Metabolized in liver by CYP3A4, some renal metabolism
Describe the mechanism of action of meglitinides (repaglinide)
Meglitinides (repaglinide) mechanism of action
- Act on beta cell K channels
- Increase K inside cell
- Depolarization
- Increase Ca flux into cell through voltage gated Ca channel
- Insulin secretion
____ is main toxicity of meglitinides (repaglinide)
Hypoglycemia is main toxicity of meglitinides (repaglinide)
____ has drug interactions with meglitinides (repaglinide)
Anti-lipidemia drug gemfibrozil (Lopid) has drug interactions with meglitinides (repaglinide)
GLP-1 mimetics are ____, ____, and ____
GLP-1 mimetics are exenatide, liraglutide, and dulaglutide
Describe GLP-1 mimetics
GLP-1 mimetics
- Incretins: GI hormones derived from proglucagon
- Promote glucose-dependent insulin secretion
- Effective in patients with T2DM
- Can result in weight loss
GLP-1 mimetics (exenatide, liraglutide, and dulaglutide) function to ____
GLP-1 mimetics (exenatide, liraglutide, and dulaglutide) function to promote glucose-dependent insulin secretion
Describe mechanism of action of GLP-1 mimetics (exenatide, liraglutide, and dulaglutide)
GLP-1 mimetics (exenatide, liraglutide, and dulaglutide) mechanism of action
- Act through GLP receptors (GPCRs)
- Act mainly through cAMP/PKA pathway but can also stimulate other signaling pathways
- Close K channels, increase Ca release, and increase release of insulin