Antidiabetic Drugs 2 Flashcards
This drug is effective at reducing fasting plasma glucose and HbA1c
Sulfonylureas
This drug stimulates insulin release from B cells: bind to the SUR1 subunit and block the ATP-sensitive K+ channel in the beta cell membrane.
Sulfonylurea
Adverse effects of sulfonylureas
- Hypoglycemia
* Weight gain
First-generation Sulfonylureas
Chlorpropamide
- Longhalf-life.
- Hypoglycemia is common, particularly in elderly patients. Contraindicated in elderly patients.
- Hyperemic flush when alcohol is ingested. Mainly due to inhibition of aldehyde dehydrogenase.
Chlorpropamide
____________may potentiate action of vasopressin and elicit an apparent syndrome of inappropriate secretion of ADH (SIADH).
Chlorpropamide
Second-generation Sulfonylureas
➢**Glyburide (Glibenclamide)
• Causes hypoglycemia in 20-30% of users.
➢ Glipizide
• Short half-life. Less likely to get cause hypoglycaemia.
• Causes hypoglycemia in 10-15% of users.
➢ Glimepiride
• Approved for once-daily use.
• Causes hypoglycemia in 9-14% of users. Approved for once- daily use.
Adverse effects of Second-generation Sulfonylureas
- Hypoglycemia
* Weight gain
Insulin Secretagogues: Meglitinides
➢ Repaglinide
• Causes Hypoglycemia
➢ Nateglinide
• Less risk of hypoglycemia.
Function and details of meglitinides
- Stimulates insulin release by binding to SUR1 and inhibiting ATP-sensitive K+ channel.
- Not as effective as sulfonylureas in reducing FPG and HbA1C levels.
- In contrast with sulfonylureas, the meglitinides have a rapid onset and short duration of action.
- Are postprandial glucose regulators.
- Must be taken before each meal; if the meal is missed the drug must be omitted.
No sulfur
Adverse effects of meglitinides
Weight gain
Hypoglycemia
Reduces glucose levels by inhibiting gluconeogenesis; does not cause insulin secretion
Inhibits gluconeogenesis by reducing gene expression of gluconeogenesis enzymes
• At the molecular level, these actions are mediated at least in part by activation of AMP-activated protein kinase (AMPK).
Biguanides - metformin
AE OF METFORMIN
- Largely GI : anorexia, nausea, vomiting, abdominal discomfort, diarrhea.
- Long term use may interfere with B12 absorption.
- Small risk of potentially fatal lactic acidosis.
- Contraindicated in patients with renal disease, hepatic disease, hypoxia, or alcoholism.
First line in type 2 DM
Metformin
- MOA : involves gene regulation
- decrease insulin resistance.
- slow onset and offset
- Less effective than sulfonylureas and Metformin in decreasing FPG and HbA1C levels.
Thiazolidinediones (TZDs)
• Decrease insulin resistance.
• Agonists of peroxisome proliferator-
activated receptor- gamma
TZDs-
Pioglitazone
Rosiglitazone
The effects on lipids are more favorable and associated with significant improvements in: HDL, TG, LDL particle concentration, and LDL particle size.
Pioglitazone
AE OF TZD
- Fluid retention, weight gain and edema.
* Contraindicated in patients with Class III or IV heart failure
Why does the FDA require monitoring of liver function with TZD therapy?
Troglitazone was the first thiazolidinedione to be approved. It caused severe hepatic toxicity and was withdrawn.
MOA of Acarbose
Reduces post prandial digestion of starch and disaccharides by deferring absorption to distal SI
- decreased postprandial hyperglycemia
• Evokes modest drop in HbA1C and FPG levels.
AE of acarbose
• Flatulence,diarrhea,abdominalpain.
• Contraindicated in IBS or any intestinal condition worsened by gas
and distension.
• Acarbose is associated with reversible hepatic enzyme elevation.
• Periodical liver function monitoring is required with acarbose therapy.
- Competitive inhibitor of intestinal a-glucosidases
- Blocks SGLT
- blocks cleaving preventing rise in glucose levels
Acarbose
- Injectable
- Analog of glucagon-like-polypeptide 1 (GLP-1).
- Derived from the salivary gland of the Gila monster.
- FullagonistathumanGLP-1receptors.
- Resistant to dipeptidyl peptidase IV (DPP-IV).
Incretin Analogs
➢Exenatide
MOA of exenatide
- Enhances glucose-dependent insulin secretion.
- Suppresses postprandial glucagon release.
- Slows gastric emptying.
- Decreases appetite.
- May stimulate β-cell proliferation