Antidiabetic Drug Flashcards
What are the main characteristics of Type I Diabetes Mellitus (IDDM)?
Type I Diabetes Mellitus (IDDM) occurs commonly in juveniles and occasionally in non-obese adults. It is associated with ketoacidosis in untreated states. Circulating insulin is virtually absent, and pancreatic B cells fail to respond to all insulinogenic stimuli.
What are the clinical features of Diabetes Mellitus?
The clinical features of Diabetes Mellitus include polyuria, polydipsia, polyphagia, blurring of vision, drowsiness or confusion, and fatigue.
Why can’t insulin be taken orally?
Insulin cannot be taken orally because it is a polypeptide and is degraded in the gastrointestinal tract (GIT).
What are the sources of exogenous insulin?
The sources of exogenous insulin include bovine and porcine insulin, human insulin produced using recombinant DNA technology, and insulin analogs like lispro and aspart, which are modifications of the amino acid sequence of human insulin.
What is the mechanism of action of Sulfonylureas?
Sulfonylureas stimulate insulin release from the β cells of the pancreas by blocking the ATP-sensitive K+ channels, resulting in depolarization and opening of calcium channels, leading to Ca2+ influx. They also reduce hepatic glucose production and increase peripheral insulin sensitivity.
What are the adverse effects of Sulfonylureas?
The adverse effects of Sulfonylureas include hypoglycemia (especially in elderly patients with impaired hepatic or renal functions), weight gain, secondary failure after prolonged treatment, and teratogenic effects in animals (avoided in pregnancy).
What is the difference between rapid-acting and short-acting insulins?
Rapid-acting insulins (e.g., lispro, aspart) have an onset of action of 5-15 minutes (S.C.) and a duration of action of 3-5 hours. Short-acting insulins (e.g., regular insulin) have an onset of action of 30-45 minutes (S.C.) and a duration of action of 6-8 hours.
What is the primary use of long-acting insulin like glargine?
Long-acting insulin like glargine is used for basal control, providing a constant release of insulin over 24 hours with no pronounced peaks.
What are the pharmacokinetics of insulin?
Insulin is often administered by subcutaneous injection but can also be given intravenously or intramuscularly. It has a half-life of 5-9 minutes, is metabolized by insulin protease (found mainly in the liver and kidney), and is eliminated in the liver and kidney (with 10% appearing in urine).
What are the main differences between first-generation and second-generation Sulfonylureas?
First-generation Sulfonylureas include tolbutamide (short-acting) and chlorpropamide. Second-generation Sulfonylureas include glibenclamide, glyburide (long-acting), glipizide (short-acting), and glimepiride.
What are the advantages of using Meglitinides over Sulfonylureas?
Meglitinides have a rapid onset and short duration of action, making them particularly effective in controlling postprandial glucose levels. The incidence of hypoglycemia and weight gain is lower compared to Sulfonylureas.
What are the side effects of insulin therapy?
The side effects of insulin therapy include hypoglycemia (which may lead to coma), allergic reactions and anaphylaxis (due to immune response to animal insulin or additives), lipodystrophy at injection sites, and insulin resistance due to antibodies against animal insulin or additive proteins.
What is the mechanism of action of Meglitinides?
Meglitinides, like repaglinide and nateglinide, bind to the ATP-sensitive K+ channels on pancreatic β cells, causing insulin release. Their action is dependent on functioning pancreatic β cells.
What is the mechanism of action of Metformin?
- Inhibit gluconeogenesis; 2. Increased peripheral glucose utilization; 3. Decreased intestinal absorption of glucose
What are the side effects of Metformin?
- Metallic taste in the mouth; 2. Gastrointestinal (anorexia, nausea, vomiting, diarrhea, abdominal discomfort); 3. Vitamin B12 deficiency (prolonged use); 4. Lactic acidosis (rare, mainly in renal & hepatic failure)
What are the advantages of Metformin over sulphonylureas?
- Does not cause hypoglycemia; 2. Does not result in weight gain; 3. It does not promote insulin secretion, so hyperinsulinemia is not a problem; 4. Preferred for obese patients
What is the mechanism of action of Thiazolidinediones (TZDs)?
Insulin sensitizer (increase insulin sensitivity in muscle, adipose tissue & liver)
What are the side effects of Thiazolidinediones (TZDs)?
- Fluid retention and peripheral edema; 2. Weight gain (possibly because TZDs may increase subcutaneous fat or cause fluid retention); 3. Hepatotoxicity
What is the mechanism of action of Alpha-glucosidase inhibitors like Acarbose?
Inhibits intestinal alpha-glucosidases in the intestinal brush border and delays carbohydrate absorption, reducing postprandial increase in blood glucose.
What are the side effects of Acarbose?
Flatulence, diarrhea, abdominal pain, and distension
What is the mechanism of action of Sodium-glucose co-transporter 2 (SGLT2) inhibitors?
Inhibits the Na-glucose co-transporter 2 (SGLT-2) in the kidney to reduce glucose reabsorption, resulting in increased urinary glucose excretion and lower plasma glucose.
What are the benefits of SGLT2 inhibitors in patients with T2DM?
- Weight reduction; 2. Decrease in systolic blood pressure and risk of heart failure (osmotic diuresis effect); 3. Less incidence of hypoglycemia
What are the contraindications for SGLT2 inhibitors?
Renal impairment, bladder cancer
What is the mechanism of action of GLP-1 receptor agonists?
- Stimulate GLP-1 receptor in the pancreas and promote insulin release; 2. Suppress glucagon secretion; 3. Slow gastric emptying, causing nausea and early satiety, leading to weight loss; 4. Reduce food intake
