Questions and Answers
What are the two types of parenchymal tissue found in the pancreas?
Glucose is stored in the liver and muscles as glycogen.
True
What is the normal range for blood glucose levels?
70-110 mg/dl
Type 1 diabetes was formally known as _______ Dependent Diabetes Mellitus.
Signup and view all the answers
What is another term for Type 2 Diabetes?
Signup and view all the answers
What is the main function of biguanides in lowering blood glucose levels?
Signup and view all the answers
Which of the following are factors contributing to Type 2 Diabetes? (Select all that apply)
Signup and view all the answers
Insulin is required in all cases of Type 2 Diabetes.
Signup and view all the answers
Which side effect is commonly associated with Metformin?
Signup and view all the answers
Insulin is a ________ that is degraded in the gastrointestinal tract if taken orally.
Signup and view all the answers
Thiazolidinediones (TZDs) bind to a receptor called Peroxisome Proliferator Activated Receptor α (PPARα)
Signup and view all the answers
Match the following insulin types with their duration of action:
Signup and view all the answers
______ side effects are related to gastrointestinal disturbances, such as flatulence and diarrhea.
Signup and view all the answers
Match the biguanide with its name:
Signup and view all the answers
Study Notes
Diabetes Mellitus
- Definition: Diabetes means high blood sugar (glucose) or hyperglycaemia, due to absolute or relative lack of insulin or less insulin sensitivity/insulin resistance.
- Criteria:
- Fasting plasma glucose level > 126mg/dL (7mmol/L)
- Plasma glucose levels > 200mg/dL (11mmol/L) at two times points during an oral glucose tolerance test (OGTT), which must be within 2 hrs of ingestion of glucose
Types of Diabetes
- Type 1 Diabetes
- Destruction of islet beta cells
- Formally known as "Insulin Dependent Diabetes Mellitus" (IDDM) or "Juvenile-onset diabetes"
- Requires exogenous insulin to sustain life
- Type 2 Diabetes
- Insulin resistance/loss of response to insulin
- Formally known as "Non-Insulin Dependent Diabetes" (NIDDM)
- Can occur at any age, including adolescence, but usually affects older individuals
- Gestational Diabetes
- Pregnant women who have never had diabetes before but have high blood sugar (glucose) levels during pregnancy
- Affects about 7-10% of all pregnant women
- Other forms
- Congenital diabetes due to genetic defects of insulin secretion
- Cystic fibrosis-related diabetes
- Steroid diabetes induced by high doses of glucocorticoids
Insulin and Its Analogues
- Insulin Administration
- Exogenous insulin is required in:
- Gestational diabetes
- Type 1 Diabetes
- Sometimes Type 2 Diabetes
- Because insulin is a polypeptide, it is degraded in the GIT (proteolytic enzymes) if taken orally
- Exogenous insulin is required in:
- Insulin Types
- Rapid-acting
- Humalog
- Injected 15 minutes before meal
- Onset = < 30 min, Peak = 30 min to 1 hour (longer depending on type), Duration = 2 to 4 hours (+/-)
- Short-acting
- Regular
- Longer onset of action compared to rapid-acting
- Onset = ½ – 1 hr, Peak = 2 – 5 hrs, Duration = 5 – 10 hrs (+/-)
- Intermediate-acting
- Lente
- Onset = 1 – 3 hrs, Peak = 6 – 14 hrs, Duration = 18 – 24 hrs (+/-)
- Long-acting
- Ultralente
- Onset = 4 – 6 hrs, Peak = 16 – 24 hrs, Duration = 24 – 28 hrs (+/-)
- Rapid-acting
- Insulin Combination
- Two (standard treatment): One in the morning, One in the late afternoon, Mix of short and intermediate
- Three to Four (intensive treatment): Mainly used for more control of the diabetes
Oral Antidiabetic Agents
- Treat DM by lowering glucose levels in the blood
- Several classes of antidiabetic drugs
- Selection depends on the nature of the diabetes, age, and situation of the person, etc.
- Classes:
- Insulin Secretagogues (Sulfonylureas and Meglitinides)
- Insulin Sensitizers
- Alpha-glucosidase inhibitors
- Sulfonylureas:
- First-generation agents (e.g., tolbutamide)
- Second-generation agents (e.g., glipizide, glyburide (glibenclamide), glimepiride)
- More effective than first-generation drugs and have fewer side effects### Sulfonylureas
- Stimulate insulin release from β cells in the pancreas by blocking ATP-sensitive K+ channels, resulting in depolarization and Ca2+ influx
- Reduce hepatic glucose production
- Increase peripheral insulin sensitivity, which may cause hypoglycemia
- Side effects: weight gain, hyperinsulinemia, hypoglycemia
- Should be used with caution in patients with hepatic and renal insufficiency
Meglitinides
- Also known as "short-acting secretagogues"
- Mechanism of action similar to sulfonylureas, but more rapidly absorbed and eliminated
- Pose a smaller risk of hypoglycaemia compared to sulphonylureas
- Include repaglinide and nateglinide
- Side effects: hypoglycemia, nausea, upper respiratory tract infection, diarrhea, dizziness, light headedness, and weight gain
Insulin Sensitizers
- Improve target cell response to insulin without increasing pancreatic insulin secretion
- Types: biguanides and thiazolidinediones (glitazones)
Biguanides
- Only currently available biguanide: metformin
- Mechanism of action:
- Reduce hepatic glucose production by inhibiting hepatic gluconeogenesis
- Increase skeletal muscle glucose uptake and metabolism
- Slow intestinal absorption of sugars
- Reduce free fatty acids (FFA)
- Side effects: nausea, vomiting, diarrhea, weight loss, and stomach pain
Thiazolidinediones (Glitazones)
- Mechanism of action:
- Bind to Peroxisome Proliferator Activated Receptor γ (PPARγ)
- Activate transcription of genes regulating glucose and fat metabolism
- Enhance production of mRNAs of insulin-dependent enzymes
- Side effects: water retention, tissue swelling (edema), and weight gain
- Include rosiglitazone and pioglitazone
- Pioglitazone is approved for use in combination with insulin, metformin, or a sulfonylurea
α-Glucosidase Inhibitors
- Mechanism of action:
- Inhibit enzymes that break down polysaccharides and sucrose in the small intestine
- Slow down glucose absorption from the gut
- Include acarbose and miglitol
- Miglitol has a similar action as acarbose, but is almost completely absorbed from the GIT, leading to higher bioavailability
- Side effects: flatulence, diarrhea, bloating, and abdominal discomfort, contraindicated in patients with inflammatory bowel disease, cirrhosis, or elevated plasma creatinine
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Test your knowledge of insulin and other common drugs used in diabetes mellitus. Learn about the role of pharmacology in treating this disease.