Chapter 49 Flashcards
(108 cards)
1
Q
What are the 3 main classes of drugs which affect blood glucose levels?
A
- Insulins
- Non-insulin antidiabetics
- Glucose-elevating agents
2
Q
What is the prototype drug for the insulin class of drugs which affect blood glucose levels?
A
Regular Insulin
3
Q
What are three drugs are that closely related to regular insulin?
A
- Aspart
- Lispro
- Glulisine
4
Q
What is the prototype drug which is a glucose-elevating agent?
A
Glucagon
5
Q
How many people in the US does Diabetes Mellitus affect?
A
- 6 million people
- 7.8% of the population
6
Q
How many people have type 1 diabetes? Type 2 diabetes?
A
Type 1 = 5-10%
Type 2 = 90-95%
7
Q
What does diabetes increase your risk of?
A
- cardiovascular disease (HTN, heart disease, stroke) - kidney failure - blindness - nervous system disease - extremity amputation
8
Q
In 2007, what was the economic cost of diabetes?
A
$174 billion
9
Q
What are the two major classes of oral antidiabetic drugs that are used to control type 2 diabetes?
A
- Sulfonylureas (anti-glycemics)
2. Non-sulfonylureas (anti-hyperglycemics)
10
Q
What is the prototype sulfonylurea?
A
Glyburide
11
Q
What is the prototype non-sulfonylurea?
A
Metformin
12
Q
What are the three body systems that are involved in the regulation and use of glucose?
A
- Liver
- Pancreas
- Skeletal muscle tissue
13
Q
What is the liver’s role in glucose regulation?
A
Liver synthesizes its own glucose supply (gluconeogenesis)
- stores and releases glucose that has been converted from dietary carbohydrates
14
Q
What happens in the liver when blood glucose is low? When it is high?
A
Low = releases its stored and synthesized glucose High = stops producing and releasing glucose
15
Q
What is the exocrine function of the pancreas?
A
Produce digestive enzymes
16
Q
What is the endocrine function of the pancreas?
A
Synthesize and secrete peptide hormones
17
Q
What are the three peptide hormones that the pancreas secretes from the islets of Langerhans?
A
- Insulin
- Glucagon
- Somatostatin
18
Q
What types of cells are contained in the islets of Langerhans?
A
- Beta cells
- Alpha cells
- Delta cells
- F cells
19
Q
What do Beta cells secrete?
A
Hypoglycemic hormone insulin
20
Q
What do Alpha cells secrete?
A
Hyperglycemic hormone glucagon
21
Q
What do Delta cells secrete?
A
Somatostatin - hormone that inhibits both glucagon and insulin secretion
22
Q
What do F cells synthesize and secrete?
A
Pancreatic polypeptides used in digestion
23
Q
What kind of tissue is the target for the action of insulin?
A
Muscle tissue
- contains the majority of insulin receptor sites
24
Q
What provides a good indication of circulating insulin levels? Why?
A
C peptide
- Proinsulin splits to form insulin and C peptide
- they will be in equal concentrations
25
What is insulin secretion most commonly triggered by?
High blood glucose levels
26
What is the role of insulin?
Lowers blood glucose levels by stimulating peripheral glucose uptake (especially skeletal muscle and fat)
- promotes the uptake and storage of glucose in the liver (in the form of glucagon)
27
Which tissues do not need insulin so that glucose can enter their cells?
- brain
- nerves
- intestine
- liver
- retina
- erythrocytes
- renal tubules
28
What factors can influence changes in blood glucose levels?
- stress
- secretion of insulin-antagonistic hormones (cortisol, E, growth hormone, glucagon, somatostatin)
- rates of hepatic synthesis of glucose
- presence of levels of insulin antibodies
- number of cellular insulin receptors
- use of glucose by peripheral cells or tissues
29
If glucagon is released, what happens in the liver?
Glucagon stimulates glycogenolysis and gluconegogenesis
| - resulting in a release of glucose into the blood
30
What are the three types of diabetes mellitus?
1. Type 1
2. Type 2
3. Gestational
31
What is diabetes insipidus?
Metabolic disorder
- high amounts of dilute urine are formed because of deficient production of ADH or inability of the kidney tubules to concentrate urine
- does not affect blood glucose levels
- is NOT treated with insulin or oral antidiabetics
32
What is the defining characteristic of Type 1 diabetes?
Autoimmune disorder
- destruction of insulin-secreting beta cells in the pancreas
- leading to absolute insulin deficiency
33
What happens if the body's reserve of insulin is depleted?
Results in HYPERglycemia
| - circulating glucose CANNOT enter the cells
34
How does ketoacidosis occur?
Body is in a hyperglycemic state
- high circulating blood glucose
- glucose cannot enter cells
- body thinks there is NOT ENOUGH glucose so it starts to break down lipids and proteins for energy
- This causes an increase in ketoacids
35
What is the final result of Type 1 diabetes?
Destruction of pancreatic beta cells
- may occur over period of months to years
- state of absolute insulin deficiency
36
What is required for all cases of Type 1 diabetes?
Insulin therapy
37
When is the onset of Type 1 diabetes?
Childhood or puberty
| - however it CAN develop at any age
38
What is Type 2 diabetes characterized by?
Insulin RESISTANCE by the tissues
| - usually a decrease in insulin production
39
What is Type 2 diabetes closely linked with?
- obesity
- sedentary lifestyle
- lack of physical exercise
40
What happens to insulin levels in Type 2 diabetes?
Normal or increased
- may be increased because the pancreas tries to overcome the resistance by producing more insulin
- b/c the peripheral tissue is resistant to insulin, insulin does not enter the cells but stays in the bloodstream
41
When is Type 2 diabetes most prevalent?
Later years in life
| - but we are seeing it younger and younger (as children get fatter and fatter)
42
What is considered the primary defect in Type 2 diabetes?
Insulin resistance
43
What is the metabolic syndrome?
An insulin-resistance syndrome
| - a precursor to the development of type 2 diabetes
44
What is the age of onset of Type 1 diabetes? Type 2?
Type 1 = usually before 20 yrs
| Type 2 = usually after 40 yrs
45
What is the incidence of Type 1 diabetes? Type 2?
Type 1 = 5 - 10%
| Type 2 = 90 - 95%
46
What is the body weight of a person with Type 1 diabetes? Type 2 diabetes?
Type 1 = Thin or underweight
| Type 2 = Overweight or obese
47
What are the clinical s/s of Type 1 diabetes?
```
Hyperglycemia
Polyphagia
Polydipsia
Polyuria
Weight loss
```
48
What are the clinical s/s of Type 2 diabetes?
```
Hyperglycemia
Fatigue
Weakness
Mild 3 P's
Fungal infections
Blurred vision
```
49
Typically when is ketoacidosis seen? (Type 1 or Type 2)
Type 1
50
What are the three ways that we can manage Type 1 diabetes (3) ?
1. Insulin injections
2. Dietary controls
3. Exercise regimen
51
What are the ways that we can manage Type 2 diabetes (5) ?
1. Weight reduction
2. Dietary controls
3. Exercise regimen
4. Oral drug therapy
5. Insulin
52
Metabolic syndrome is a combination of which conditions?
1. Insulin resistance
2. Compensatory hyperinsulinemia (to maintain glucose homeostasis)
3. Obesity
53
If a patient is undiagnosed with Type 2 diabetes, what are they are increased risk for?
- coronary artery disease
- stroke
- peripheral vascular disease
54
How does Gestational diabetes mellitus occur?
When a woman's pancreatic function is not sufficient to overcome the insulin resistance created by the anti-insulin hormones secreted by the placenta
55
What are some examples of anti-insulin hormones that are secreted by the placenta?
- Estrogen
- Prolactin
- Cortisol
- Progesterone
56
What can happen if gestational diabetes goes undiagnosed?
- Preeclampsia
- Fetal macrosomia (large infants)
- birth trauma
- perinatal mortality
57
What are some endogenous sources which may produce diabetes?
- genetic defects in beta cell function, insulin action or diseases of the pancreas (cystic fibrosis)
58
What are some exogenous sources which may produce diabetes?
- surgical removal of pancreas, ingestion of certain drugs/chemicals (glucocorticoid steroids)
59
What are the 4 criteria that are used to diagnose diabetes?
1. Plasma glucose = 126 mg/dL after fasting for 8 hours
2. Plasma glucose = 200 mg/dL during an oral glucose tolerance test
3. A1C level of > 6.5%
4. Symptoms of diabetes and hyperglycemia or hyperglycemic crisis at any time of the day (regardless of last meal)
60
What is an oral glucose tolerance test?
75 g of glucose is dissolved in water is ingested
61
How does the A1C test measure the average blood glucose level from the last 2-3 months?
Hemoglobin molecules react with glucose --> glycosylated hemoglobin
- it will last the lifespan of the RBC to determine the patient's blood glucose level over time
62
What are the classic signs of hyperglycemia?
- excessive urination
- excessive thirst
- fatigue
- dry or itchy skin
- poor wound healing
- vision changes
63
At what value is a blood glucose level considered hyperglycemic?
> 126 mg/dL
64
What is the dawn phenomenon?
Blood glucose levels are at their highest between 5am and 6am
- release of growth hormone overnight is believed to produce this increase in blood glucose
65
How do we treat dawn phenomenon?
Providing larger doses of intermediate-acting insulin at bedtime
66
What is the Somogyi effect?
Produces early morning hyperglycemia
- precipitating factor is actually a HYPOglycemic event sometime after midnight
- body compensates by releasing glucose from the liver
- when the body overcompensates --> REBOUND HYPERGLYCEMIA occurs
67
How do we treat the Somogyi effect?
- lowering the insulin dose
- increasing dietary intake at bedtime
- or both
68
What are the chronic complications of diabetes usually classified as?
1. Microvascular
2. Macrovascular
- according to the type of blood vessel damaged
69
What are some of the macrovascular complications?
- atherosclerotic vascular disease
- myocardial infarction
- cerebrovascular accident
70
What are some of the microvascular complications?
- cataracts, glaucoma, and blindness from retinopathy
- lower extremity infections and gangrene
- foot ulcers
- Charcot joints
- renal failure
- sexual dysfunction
71
What can severe hypoglycemia result in?
- coma
| - altered consciousness
72
What is Basal insulin?
The continuous secretion that maintains glucose homeostasis
| body's baseline level of insulin
73
What is Prandial insulin?
Insulin secretion stimulated in response to meals
74
What is the non-physiologic regimen of diabetic therapy?
Does not mimic normal beta-cell secretion
| - ideal for those newly diagnosed (those who still produce some endogenous insulin)
75
What is the physiologic regimen of diabetic therapy?
Used in complete beta-cell failure when glucose control cannot be achieved with the non-physiologic regimen
76
What is correctional (or supplemental) insulin used for?
Patients with diabetes who are hospitalized (or ill), may require doses of insulin to correct any elevations in blood glucose
77
What are the 4 kinds (types) of insulin?
- rapid
- short (regular)
- intermediate
- long-acting
78
What is the prototype insulin?
Short-acting insulin
79
What are the trades names for Regular insulin?
- Novolin-R
| - Humulin-R
80
When is insulin indicated for Type 1 diabetics? Type 2?
Type 1 = for all patients
Type 2 = for patients that cannot control their hyperglycemia with diet and exercise, weight reduction, oral antidiabetic drugs
81
What is regular insulin used to control?
To correct a current glucose elevation or an expected rise after eating
- not for use all day due to it's short duration
82
Why can regular insulin NOT be given orally?
It is destroyed by gastric acids
83
Which SC injection site provides the most rapid absorption?
Abdominal SC layer
- next is arm
- then thigh
- finally buttocks
84
How long does insulin remain stable at room temperature for?
1 month
| - for longer storage, place in refrigerator
85
Where is insulin filtered and where is it reabsorbed?
Filtered in glomerulus
| Reabsorbed in proximal renal tubule (98%)
86
How does renal impairment affect diabetic patients?
It reduces the amount of insulin excreted, thus reducing the amount of insulin required
- renal function impairment occurs commonly in diabetic patients b/c of vascular insufficiency
87
When is insulin contraindicated?
In times of hypoglycemia
88
What are the earliest signs of hypoglycemia?
- fatigue and malaise
- trembling
- irritability
- headache
- nausea
- numbness
- paresthesias
- muscle weakness
89
How can lipodystrophy be caused?
By repetitive SC injections into the same injection site
| = disturbances in fat metabolism
90
With insulin, why do we rotate WITHIN the site, and not simply change injection sites?
It would substantially change the absorption of insulin and the blood glucose levels of the patient
91
If a patient has a low hematocrit, what will this do to the blood glucose reading?
Create a falsely HIGHER reading
92
If a patient has a high hematocrit, what will this do to the blood glucose reading?
Create a falsely LOWER reading
93
If a patient is experiencing shock or dehyration, what will this do to the blood glucose reading?
Create a falsely LOWER reading
94
What can you give your patient if they are hypoglycemic?
1. 4 oz juice or non-diet soda
2. 4 oz water with 4 tsp of sugar
3. 8 oz non fat milk
95
When mixing types of insulin, which one do you draw up first?
Short-acting drawn into the syringe first
96
What are the three rapid-acting insulins?
1. Aspart (NovoLog)
2. Lispro (Humalog)
3. Glulisine (Apidra)
97
What does protamine do when it is added to insulin?
Prolongs the action of the insulin
98
What are the separate parts of NovoLog Mix 70/30?
1. 70% Aspart protamine
| 2. 30% Aspart
99
What does NPH stand for?
Neutral Protamine Hagedorn
100
What does the "N" signify on insulin? Is it clear or cloudy?
Intermediate acting
| - cloudy in appearance
101
When is the onset, peak and duration of NPH?
Onset: 1 - 1.5 hours
Peak: 4 - 12 hours
Duration: up to 24 hours
102
What is Detemir (Levemir)? (Rapid, short, intermediate or long acting)
Long acting insulin
| - clear insulin
103
What are the two main classes of oral anti-diabetic medications?
1. Sulfonylureas
| 2. Non-sulfonylureas
104
How are second generation different than first generation drugs?
Second generation contain fewer drug interactions
105
What is Glyburide?
Potent second generation oral sulfonylurea
106
How is Glyburide absorbed? Metabolized?
| Excreted?
Absorbed: In the GI tract
Metabolized: Liver
Excreted: urine and feces
107
Why is Glyburide ineffective on Type 1 diabetes?
Because there is no endogenous release of insulin
| - cannot stimulate the beta cells to produce insulin
108
Why should Glyburide be used cautiously in patients with know hepatic or renal disease?
May elevate drug blood levels
| - increase the risk of hypoglycemic reactions
