Chapter 32: Diabetes Drugs Flashcards
Pancreas
Located behind the stomach
Exocrine and endocrine gland
Produce insulin and glucagon which are important in glucose homeostasis
Glycogen: excess glucose stored in liver and skeletal muscle tissue
Glycogenolysis: conversion of glycogen to glucose when needed
Insulin
Direct effect on fat metabolism
Stimulates Lopo genesis and inhibits lipolysis
Stimulates protein synthesis
Promotes intracellular shift of K and Mg into cells
Cortisol, epinephrine, and GH work synergistically with glucagon to counter the effects of insulin
What is Diabetes Mellitus (DM)?
A group of progressive changes in the body as a result of glucose elevation. For this reason, DM can be considered a syndrome rather than a disease
Two types: type 1 and type 2
Signs and symptoms of DM
- Elevated fasting blood glucose (>126 mg/dL) or a hemoglobin A1C (HbA1C) level > or = 6.5%
- Polyuria, polydipsia, or polyphagia
Glycosuria
Unexplained weight loss
Fatigue
Blurred vision
What is Type 1 DM?
*A lack of insulin production or production of defective insulin
Affected patients need exogenous insulin
Fewer than 10% of all DM cases are Type 1
*Complications: diabetic ketoacidosis (DKA)
What is Type 2 DM?
Most common type: 90% of cases
- Caused by insulin deficiency and insulin resistance
- Many tissues are resistant to insulin: reduced # of receptors OR insulin receptors are less responsive
- Complication: hyperosmolar nonketotic syndrome (HHNS)
Why does Type 2 DM occur?
Several comorbid conditions:
* Obesity, coronary heart disease, dyslipidemia, hypertension, microalbuminemia (protein in the urine), increased risk for thrombotic events (metabolic syndrome is a combo of these)
These comorbidities are collectively referred to as metabolic syndrome, insulin-resistance syndrome, or syndrome X
What is Gestational Diabetes?
*Hyperglycemia that develops during pregnancy
Insulin must be given to prevent birth defects
Usually subsides after delivery
*30% of patients may develop Type 2 DM within 10 to 15 years
The infant is at risk for developing diabetes as well
Insulins will he started because they are a naturally occurring hormone within the body and will not harm the mother or fetus during pregnancy
Long-term complications of both types of diabetes
- Macrovascular (atherosclerotic plaque) of the coronary arteries, cerebral arteries, and peripheral vessels
- Microvascular (capillary damage) including retinopathy, neuropathy, and nephropathy
Acute Diabetic Conditions
*DKA (Seen in Type 1 DM) manifests as hyperglycemia, ketones one the serum, acidosis, dehydration, and electrolyte imbalances
DKA is seen in ~25-30% of patients that are newly diagnosed with Type 1 DM
*HHNS (Seen in Type 2 DM) manifests as hyperglycemia (very high- over 600) and severe dehydration. It has a high mortality rate and develops over a long period of time.
Screening for Diabetes
Prediabetes puts patients in a category of increased risk for DM. HbA1C of 5.7-6.4%. Fasting levels > or = to 100mg/dL but less than 126 mg/dL. Impaired glucose tolerance test (oral glucose challenge).
Screening is recommended every 3 years for all patients 45 years and older
Nonpharmacologic Tx interventions
- Type 1: always requires insulin therapy
- Type 2: weight loss, improved dietary habits, smoking cessation, reduced alcohol consumption, and regular physical exercise
Clinical Tx goal
*HbA1C <7%
<5.7%= normal; 5.7-6.4%= prediabetes; >6.5%= Type 2 Diabetes
Fasting blood glucose goal for diabetic patients of 70-130 mg/dL (slightly elevated; usually 70-100)
Estimated average glucose
Diabetes Tx
- Type 1: insulin therapy
* Type 2: lifestyle changes, oral drug therapy, insulin when the others no longer provide glycemic control
Types of Antidiabetic Drugs
- Insulin
- Oral hypoglycemic drugs: both aim to produce normal blood glucose states
Some new injectable hypoglycemic drugs may be used in addition to insulin or antidiabetic drugs
Insulins
Function as a substitute for the endogenous hormone
Effects are the same as normal endogenous insulin
Restores the diabetic patients ability to: metabolize carbs/ fats/ protein, store glucose in the liver, and convert glycogen to fat stores
*Goal: tight glucose control to reduce the incidence of long-term complications
All insulins are human derivatives
Rapid-Acting Tx for Types 1 & 2 DM
Most rapid onset of action (5-15 minutes)
Peak: 1-2 hours
Duration: 3-5 hours
Patient must eat a meal after injection
*Insulin Lispro (Humalog)- similar action to endogenous insulin
Insulin Aspart (NovoLog), Insulin Glulisine (Apidra)
*May be given SQ or via continuous SQ infusion pump (but not IV)
Patients blood sugar will begin to drop quickly right away but also clears the body quickly; prevents huge drops in blood glucose
Rapid-Acting Insulins: Drug Profile (Afrezza)
Rapid-Acting Insulin that is inhaled
Peak: 12-15 minutes
Short DOA: 2-3 hours
Administered within 20 minutes before each meal
Must be given in conjunction with long acting insulin’s or oral diabetic agents (for Type 2 DM)
Side Effects: hypoglycemia, cough and throat pain
Contraindicated in smokers and those with chronic lung disease
*BBW: regarding the risk of acute bronchospasms
Short-Acting Insulins
- Regular Insulin (Humulin R)
- Routes of admin: IV bolus, IV infusion, IM, SQ
Onset (SQ): 30-60 minutes
Peak (SQ): 2.5 hours
DOA (SQ): 6-10 hours
These are usually for pumps or pens; insulin syringes are orange and must not use a different color!!
Intermediate-Acting Insulins
- Insulin Isophane Suspension (also called NPH)
- Cloudy appearance
- Often combined with regular insulin
Onset: 1-2 hours
Peak: 4-8 hours
DOA: 10-18 hours
Long-Acting Insulins
*Insulin Glargine (Lantus) is a clear, colorless solution; constant level of insulin in the body; usually dosed once daily; referred to as basal insulin, and has no peak because it is given at a steady rate of delivery because it develops micro deposits that are slowly released over 24 hours when given SQ
Can be dosed every 12 hours; onset: 1-2 hours; has a duration of 24 hours. Toujeo is more concentrated U-300
Insulin Detemir (Levemir): DOA is dose dependent, lower doses require BID dosing, higher doses may be given once daily
Insulin Glargine (Basaglar): Biosimilar insulin; U-100
Insulin Degludec (Tresiba): Ultra long acting, once daily, U-100 or U-200
Fixed combination Insulins
Humulin 70/30 or 50/50 Novolin 70/30 Humalog Mix 75/25 Humalog 50/50 NovoLog 70/30
Mix them by rolling the vial between your hands
Each contains 2 different insulins: one intermediate and one rapid or short acting.
Always do clear before cloudy! Or rapid/ insulin before drawing up the intermediate insulin solution
Sliding scale Insulin
SQ rapid acting (lispro or aspart) or short acting (regular) insulins are adjusted according to blood glucose test results. SQ is ordered in an amount that increases as the blood glucose increases
Commonly used in hospitalized diabetic patients, those on parenteral nutrition, or enteral tube feedings
This delays insulin admin until hyperglycemia occurs resulting in large swings in glucose control
Basal bolus Insulin Dosing
Preferred method of Tx for hospitalized patients with DM
Mimics a healthy pancreas by delivering basal insulin constantly as a basal and then as needed as a bolus
Basal insulin is a long acting insulin (Glargine)
Bolus insulin (insulin lispro or aspart)
Oral Antidiabetic Drugs
Used for Type 2 DM
Effective Tx involves careful monitoring of blood glucose levels, therapy with one or more drugs, Tx of associated comorbid conditions such as high cholesterol and high blood pressure
If lifestyle modifications and the max tolerated met form in dose do not achieve the recommended HbA1C goals after 3-6 months, additional Tx should be given with a second oral agent or insulin
Other oral Antidiabetic Meds to be used with Metformin
Sulfonylureas, Glinides, Thiazolidinediones, Incretin, and Na Glucose Cotransporter (SGLT2) Inhibitors
This is because they act on insulin activity: if they can prevent glucose production/ absorption, they can combine with meds that have an impact on insulin activity
Main side effect of insulin producing meds or meds that make insulin more available: hypoglycemia (e.g., Sulfonylureas; NOT Metformin)
Metformin (Glucophage) is in the Biguanide class
A 1st line drug for Type 2 DM Tx (not used in Type 1)
They decrease production of glucose by the liver, decrease intestinal absorption of glucose, increase uptake of glucose by tissues, and do not increase insulin secretion from the pancreas (does not cause hypoglycemia)
Biguanides-Metformin Side Effects
Because they decrease the absorption of glucose in intestines, primary side effects are GI related: abd. bloating, nausea, cramping, diarrhea, feeling of fullness
Possible metallic taste due to a decrease in vitamin B12 levels
Lactic acidosis is rare but lethal and may occur with radiologic diagnostic testing with contrast dye (D/C within 48 hours) and in foods high in iodine (e.g., seafood, tofu, iodine salt, etc.)
Does not cause hypoglycemia
Hypoglycemia
Below 50 mg/dL
Mild cases can be treated with diet— increase protein and decrease carbs— to prevent rebound postprandial hypoglycemia
Early S/S: confusion, irritability, tremor, sweating
Late S/S: hypothermia, seizures (monitor closely), coma and death will occur if left untreated
Given patient glucose tabs/ gel, corn syrup, honey, fruit juice, nondiet soft drink, small snack like crackers or sandwich or any oral forms of sugar if awake and alert and hypoglycemic.
If unconscious or comatose, give 50% dextrose in water (D50W) or IV glucagon and monitor blood glucose levels
Before giving these meds, obtain and document:
A thorough Hx, VS, blood glucose levels, HbA1C level, and any potential complications and drug interactions
What to assess before giving the meds:
Patients ability to consume food
N/V
Whether patient eats because if not, hypoglycemia may be a problem
If NPO for procedure or test— consult provider to clarify orders
Other conditions that are concerning because they increase concerns associated with DM:
When the patient is under stress
When the patient has an infection
When the patient has an illness or has experienced trauma
When the patient is pregnant or lactating
Insulin NRSG Implications
Order and prepared dosages are double checked with another nurse
Check blood glucose before giving insulin
Roll vials between hands instead of shaking them to mix suspensions
Ensure correct storage: can store at room temp for 1 month
ONLY use insulin syringes (calibrated in units) to measure & give insulin
When drawing up 2 types into 1 syringe, always withdrawal the regular or rapid-acting insulin first. Or remember clear before cloudy (NPH- intermediate)
Oral Antidiabetic NRSG Implications:
Always check blood glucose before giving
Metformin is taken with meals to reduce GI effects
Metformin will need to be D/C’d if the pt. Is to undergo studies with contrast dye because of possible renal effects- check with prescriber
