endocrine agents
TRANSCRIPT
Endocrine Agents
Chapters 29, 30, 31 & 32
Pituitary gland(Hypophysis) The Pituitary gland is an endocrine
gland the size of a pea located at the bse of the skull. Divided into 2 lobes:Anterior pituitary (adenohypophysis)Oxytocin, ADHPosterior pituitary (neurohypophysis)Growth hormone, prolactin, FSH, Thyroid,
endorphins
Figure 29-1 Pituitary hormones. (From L.M. McKenry & E. Salerno (2003). Mosby’s pharmacology in nursing – revised and updated (21st ed.). St. Louis, MO: Mosby.)
Pituitary Agents Anterior pituitary agents
cosyntropin somatotropin octreotide
Posterior pituitary agents vasopressin desmopressin
Uses Replacement therapy to make up for
hormone deficiency Drug therapy to produce a specific
hormone response when a hormone deficiency is present
Diagnostic aids to determine hypofunction or hyperfunction of a specific hormonal function
Mechanism of Action Differ depending on the agent Either augment or antagonize the
natural effects of the pituitary hormones
Indications corticotropin
Stimulation of release of cortisol from adrenal cortex
Used to diagnose, but not treat, adrenocortical insufficiency
Multiple sclerosis corticotropin insufficiency caused by
long-term corticosteroid use (↓inflammation ↓histamine↑edema)
Indications (cont’d)
somatropin (mimics GH) Recombinantly made growth hormone (GH) Stimulate skeletal growth in clients with
deficient GH, such as hypopituitary dwarfism Octreotide(inhibits GH release)
Alleviates or eliminates certain symptoms of carcinoid tumours, acromegaly
Indications (cont’d) vasopressin and desmopress (mimic ADH)
Used in the treatment of diabetes insipidus (not diabetes mellitus)
Used in the treatment of various types of bleeding, especially GI bleeding
desmopressin is useful for increasing factor VIII (anti-hemophilic factor):
• Hemophilia A• Type I von Willebrand’s disease
Nursing Implications (cont’d)
Agents should not be discontinued abruptly
Do not take OTC products without checking with health care provider
Parents of children who are receiving growth hormones should keep a journal reflecting the child’s growth
Nursing Implications (cont’d) Monitor for therapeutic responses
somatropin should increase growth in children
desmopressin, vasopressin should reduce severe thirst and decrease urinary output, decrease GI bleeding
Thyroid Gland One of the largest endocrine glands Secretes three hormones essential for
proper regulation of metabolism Thyroxine (T4) Triiodothyronine (T3) Calcitonin
Located near the parathyroid gland Involved in many bodily processes, growth,
body temperature regulation, cardiovascular, endocrine & neuromuscular functions.
Iode from diet is responsible for the synthesis thyroglobuline
Hypothalamus secretes TSH that stimulates the thyroid to break down thyroglobulin into T3 & T4 and is released into the circulation
Hypothyroidism: Deficiency in Thyroid Hormones
Primary: abnormality in the thyroid gland itself. Most common cause is hashimoto’s thyroiditis.
Secondary: results when the pituitary gland is dysfunctional and does not secrete TSH
Thyroid abnormalitiesCretinism: Hyposecretion of thyroid hormone during youth. Low metabolic rate, retarded growth and sexual development, possibly mental retardation
Myxedema: Hyposecretion of thyroid hormone as an adult. Decreased metabolic rate, loss of mental and physical stamina, weight gain, loss of hair, firm edema, yellow dullness of the skin
Goiter: Enlargement of the thyroid gland. Results from overstimulation by elevated levels of TSH. TSH is elevated because there is little or no thyroid hormone in circulation
Hypothyroidism: pathologies
Hashimoto’s thyroiditis Postoperative hypothyroidism Postpartum thyroiditis
Hypothyroidism Common symptoms
Thickened skin Hair loss Constipation Lethargy Anorexia
Thyroid Preparations levothyroxine * most common
Synthetic thyroid hormone T4
liothyronine Synthetic thyroid hormone T3
Mechanism of Action Thyroid preparations are given to
replace what the thyroid gland cannot produce to achieve normal thyroid levels.
Thyroid drugs work the same way as thyroid hormones
Indications To treat all three forms of hypothyroidism levothyroxine is the preferred agent
because its hormonal content is standardized; therefore, its effect is predictable
Also used for thyroid replacement in clients whose thyroid glands have been surgically removed or destroyed by radioactive iodine in the treatment of thyroid cancer or hyperthyroidism
Side Effects Cardiac dysrhythmia is the most
significant adverse effect May also cause:
Tachycardia, palpitations, angina, hypertension, insomnia, tremors, headache, anxiety, nausea, diarrhea, menstrual irregularities, weight loss, sweating, heat intolerance, others
Hyperthyroidism: Excessive Thyroid Hormones: free T3 & T4
Caused by several diseases Graves’ disease Toxic nodular disease Multinodular disease Thyroid storm Thyroid cancer Pituitary hormones
Hyperthyroidism Affects multiple body systems, resulting in
an overall increase in metabolism Wt loss Diarrhea – Fatigue Flushing – Palpitations Increased appetite – Nervousness Muscle weakness – Heat intolerance Sleep disorders – Irritability Altered menstrual flow
Treatment of Hyperthyroidism Radioactive iodine (131I) works by
destroying the thyroid gland Surgery to remove all or part of the
thyroid gland Antithyroid drugs: thioamide
derivatives methimazole propylthiouracil (PTU)
Antithyroid Agents Used to palliate hyperthyroidism and
to prevent the surge in thyroid hormones that occurs after the surgical treatment or during radioactive iodine treatment for hyperthyroidism
May cause liver and bone marrow toxicity
Nursing Implications Assess for drug allergies, contraindications,
potential drug interactions Obtain baseline vital signs, weight Cautious use advised for those with cardiac
disease, hypertension, and pregnant women
Teach client to take thyroid agents once daily in the morning to decrease the likelihood of insomnia if taken later in the day
Nursing Implications (cont’d) Teach client to take the medications at
the same time every day Teach clients to report any unusual symptoms, chest pain, or heart palpitations
Teach clients not to take OTC medications without physician approval
Teach clients that therapeutic effects may take several months to occur
Nursing Implications (cont’d) Antithyroid medications
Better tolerated when given with food Give at the same time each day to
maintain consistent blood levels Never stop these medications abruptly Avoid eating foods high in iodine
(seafood, soy sauce, tofu, and iodized salt)
Nursing Implications (cont’d) Monitor for therapeutic response Monitor for side/adverse effects
Symptoms of overdose of thyroid hormones include cold intolerance, depression, edema
Adrenal GlandAn endocrine gland that sits on tops of the
kidneysIt is composed of Adrenal cortex & Adrenal
medulla chiefly responsible for regulating the stress
response through the synthesis of corticosteroids and catecholamines, including cortisol and adrenaline.
Each portion has different functions and secretes different hormones
Table 32-1 Adrenal gland: characteristics
Adrenal Gland (cont’d) Adrenal medulla secretes:
Epinephrine Norepinephrine
Adrenal cortex secretes corticosteroids Glucocorticoids Mineralocorticoids (primarily aldosterone) All adrenal cortex hormones are steroid
hormones
Box 32-1 Adrenal Cortex Hormones: Biological Functions
Adrenocortical HormonesOversecretion leads to Cushing’s syndrome↑ cortisol in the blood. Cushings disease is very similar to
Cushings syndrome in that all physiologic manifestations of the conditions are the same.
↑wt gain, moon face, ↑sweating,thinning of skin,buffalo hump, histuism
Undersecretion leads to Addison’s disease Addison's disease is an endocrine or hormonal disorder that occurs in
all age groups and afflicts men and women equally. The disease is characterized by weight loss, muscle weakness, fatigue, low blood pressure, and sometimes darkening of the skin in both exposed and nonexposed parts of the body.
Adrenocortical Hormones (cont’d) Can be either synthetic or natural Many different agents and forms Glucocorticoids
Topical, systemic, inhaled, nasal Mineralocorticoid
Systemic Adrenal steroid inhibitors
Systemic
Adrenocortical Hormones (cont’d) Glucocorticoids
betamethasone (several formulations) fluticasone propionate hydrocortisone (several formulations) cortisone methylprednisolone prednisone Many others
Adrenocortical Hormones (cont’d) Mineralocorticoid
fludrocortisone acetate (Addison’s disease)
Adrenal steroid inhibitors Ketoconazole (Cushing's syndrome
(high blood levels of cortisol)
Mitotane (adrenocortical carcinoma)
Mechanism of Action Most exert their effects by modifying
enzyme activity Different agents differ in their potency,
duration of action, and the extent to which they cause salt and fluid retention
Glucocorticoids inhibit or help control inflammatory and immune responses
Indications Wide variety of indications
Adrenocortical deficiency Cerebral edema Collagen diseases Dermatological diseases GI diseases Exacerbations of chronic respiratory
illnesses, such as asthma and COPD
Indications (cont’d) Organ transplant (decrease immune
response) Palliative management of leukemias
and lymphomas Spinal cord injury
Indications (cont’d) Glucocorticoids given:
By inhalation for control of steroid-responsive bronchospastic states
Nasally for rhinitis and to prevent the recurrence of polyps after surgical removal
Topically for inflammations of the eye, ear, and skin
Indications (cont’d) Antiadrenals (adrenal steroid
inhibitors) Used in the treatment of Cushing’s
syndrome
Contraindications Drug allergies
Serious infections, including septicemia, systemic fungal infections, and varicella
Side Effects Potent effects on all body systems
Cardiovascular• Heart failure, cardiac edema, hypertension
—all due to electrolyte imbalances CNS
• Convulsions, headache, vertigo, mood swings, nervousness, insomnia, others
Side Effects (cont’d) Potent effects on all body systems
Endocrine• Growth suppression, Cushing’s syndrome,
menstrual irregularities, carbohydrate intolerance, hyperglycemia, others
GI• Peptic ulcers with possible perforation,
pancreatitis, abdominal distention, others
Side Effects (cont’d) Potent effects on all body systems
Integumentary• Fragile skin, petechiae, ecchymosis, facial
erythema, poor wound healing, hirsutism, urticaria
Musculoskeletal• Muscle weakness, loss of muscle mass,
osteoporosis Other
• Weight gain
Nursing Implications (cont’d) Assess for contraindications to adrenal
agents, especially the presence of peptic ulcer disease
Assess for drug allergies and potential drug interactions (prescription and OTC)
Systemic forms may be given by oral, IM, IV, or rectal routes (not SC)
Oral forms should be given with food or milk to minimize GI upset
Nursing Implications (cont’d) After using an inhaled corticosteroid,
instruct clients to rinse their mouths to prevent possible oral fungal infections
Teach clients on corticosteroids to avoid contact with people with infections and to report any fever, increased weakness, lethargy, or sore throat
Nursing Implications (cont’d) Sudden discontinuation of these agents
can precipitate an adrenal crisis caused by a sudden drop in serum levels of cortisone
Doses are usually tapered before the agent is discontinued
Clients should be taught to take all adrenal medications at the same time every day, usually in the morning, with meals or food
Diabetes Mellitus Two types
Type 1 Type 2
Hyperglycemia Fasting plasma glucose >7 mmol/L
Hypoglycemia Blood glucose level <2.8 mmol/L
Gestational diabetes
Signs & Symptoms of DM Polydipsia Polyuria Polyphagia Wt loss Fatigue Blurred vision
Table 31-1 Type 1 and type 2 diabetes: characteristics
Type 1 Diabetes MellitusIDDM characterized by loss of the insulin-
producing beta cells of the islets of Langerhans of the pancreas leading to a deficiency of insulin.
Affected clients need exogenous insulin Complications
Retinopathy, nephropathy, neuropathy Diabetic ketoacidosis (DKA) Oral antihyperglycemic agents not
effective
Type 2 Diabetes Mellitus Most common type Caused by insulin deficiency and insulin
resistance, but there is not an absolute of insulin production
Many tissues are resistant to insulin Reduced number insulin receptors Insulin receptors less responsive↑Obesity among children and adolescent is
increasing the incidence
Type 2 diabetesMetabolic syndrome
The cluster of co-occurring conditions of:↑ Abdominal obesity, ↑triglycerides, ↑BPAre strongly associated with the
development of type 2 diabetes.Obesity worsens insulin resistence because
adipose tissue is the site of large porportions of the body’s defective insulin receptors.
Type 2 Diabetes Mellitus (cont’d) Several comorbid conditions
Glucose intolerance Obesity Dyslipidemia Hypertension Insulin resistance Hyperinsulinemia Microalbuminemia (protein in the urine) Enhanced conditions for embolic events (blood
clots) Heart disease
Types of Antidiabetic Agents Insulins Oral antihyperglycemic agents Both aim to produce normal blood
glucose states
Human-Based Insulins Rapid acting,(aspart, lispro) Short acting (regular, humulinR, Toronto) Intermediate acting (Humulin N, NPH) Long acting (glargine, detemir) Combination Insulin products (humulog,
humulin 30/70 20/80)
Regular insulin • The only insulin product that can be given by IV
bolus, IV infusion, or even IM
Types of insulin available in Canada
See diagram
Sliding-Scale Insulin Dosing SC regular insulin doses adjusted
according to blood glucose test results
Typically used in hospitalized diabetic clients
Subcutaneous regular insulin is ordered in an amount that increases as the blood glucose increases
Table 31-3 Insulin mixing compatibilities
Oral Antidiabetic Agents Used for type 2 diabetes Treatment for type 2 diabetes includes
lifestyle modifications Diet, exercise, smoking cessation, weight loss
Oral antihyperglcemic agents may not be effective unless the client also makes behavioural or lifestyle changes
Oral Antidiabetic Agents (cont’d) Insulin secretagogues: 2 classes of drugs
able to stimulate insulin secretion: Sulfonylureas
• chlorpropamide, tolbutamide• glimepiride, gliclazide, glyburide
Nonsulfonureas• repaglinide, nateglinide
Biguanides metformin
Oral Antidiabetic Agents (cont’d) Alpha-glucosidase inhibitors
acarbose Thiazolidinediones (Actos)
pioglitazone, rosiglitazone Also known as “glitazones”
Oral Antihyperglycemic Agents:Mechanism of Action Sulfonylureas (Glyburide)
Stimulate insulin secretion from the beta cells of the pancreas, thus increasing insulin levels
Forces the extra glucose out of the blood into the cells where it can be stored and used for energy.
Beta cell function must be present Improve sensitivity to insulin in tissues Result: lower blood glucose levels
Oral Antihypoglycemic Agents:Mechanism of Action (cont’d)
Biguanides (metformin) Decrease production of glucose by the
liver Increase uptake of glucose by tissues Do not increase insulin secretion from
the pancreas therefore does not cause hypoglycemia
Oral Antihyperglycemic Agents:Mechanism of Action (cont’d)
Alpha-glucosidase (New drug category!) inhibitors: Acarbose (Precose)
Reversibly inhibit the enzyme alpha-glucosidase in the small intestine Result: delayed absorption of glucose Must be taken with meals to prevent
excessive postprandial blood glucose elevations
Oral Antihyperglycemic Agents:Mechanism of Action (cont’d)
Thiazolidinediones (Actos) (New drug category!) Decrease insulin resistance “Insulin sensitizing agents” Increase glucose uptake and use in
skeletal muscle Inhibit glucose and triglyceride
production in the liver
Oral Antihyperglycemic Agents:Indications
Used alone or in combination with other agents and/or diet and lifestyle changes to lower the blood glucose levels in clients with type 2 diabetes
Oral Antihypoglcemic Agents: Side Effects
Sulfonylureas (Glyburide) Hypoglycemia, hematological effects,
nausea, epigastric fullness, heartburn, many others
Biguanides (Metformin) Abdominal bloating, nausea, cramping,
diarrhea, metallic taste, reduced vitamin B12 levels
Oral Antihyperglycemic Agents: Side Effects (cont’d)
Alpha-glucosidase inhibitors (arcabose) Flatulence, diarrhea, abdominal pain
Thiazolidinediones (Actos) Moderate weight gain, edema, mild
anemia, hepatic toxicity
Antihyperglycemic Agents:Nursing Implications Before giving any drugs that alter
glucose levels, obtain and document: A thorough history Vital signs Blood glucose level Potential complications and drug
interactions
Nursing Implications Before giving any drugs that alter
glucose levels:1. Assess the client’s ability to consume food2. Assess for nausea or vomiting3. Hypoglycemia may be a problem if
antihyperglycemic agents are given and the client does not eat
4. If a client is NPO for a test or procedure, consult physician to clarify orders for antihyperglycemic drug therapy
Nursing Implications (cont’d) Keep in mind that overall concerns
for any diabetic client increase when the client: Is under stress Has an infection Has an illness or trauma Is pregnant
Nursing Implications (cont’d) Thorough client education is
essential regarding: Disease process Diet and exercise recommendations Self-administration of insulin or oral
agents Potential complications
Nursing Implications (cont’d) When insulin is ordered, ensure:
1. Correct route2. Correct type of insulin3. Timing of the dose4. Correct dosage
Insulin order should be prepared dosages are second-checked with another nurse
Nursing Implications (cont’d) Insulin
Check blood glucose level before giving insulin Roll vials between hands instead of shaking
them to mix suspensions Ensure correct storage of insulin vials ONLY insulin syringes, calibrated in units, are
to be used to measure and give insulin Ensure correct timing of insulin dose with
meals
Nursing Implications (cont’d) Insulin (cont’d)
When drawing up two types of insulin in one syringe, always withdraw the regular insulin first
Provide thorough client education regarding self-administration of insulin injections, including timing of doses, monitoring blood glucoses, and injection site rotations
Nursing Implications (cont’d) Oral antihyperglycemic agents
Always check blood glucose levels before giving
Usually given 30 minutes before meals Alpha-glucosidase inhibitors are given
with the first bite of each main meal metformin is taken with meals to
reduce GI effects
Symptoms of hypoglycemia include:
hunger nervousness and shakiness perspiration dizziness or light-headedness sleepiness confusion difficulty speaking feeling anxious or weak
Nursing Implications (cont’d) Assess for signs of hypoglycemia If hypoglycemia occurs:
Give glucagon Have the client eat glucose tablets or
gel, corn syrup, honey, fruit juice or nondiet soft drink
Or have the client eat a small snack such as crackers or half a sandwich
Monitor blood glucose levels
Nursing Implications (cont’d) Monitor for therapeutic response
Decrease in blood glucose levels to the level prescribed by physician
Measure hemoglobin A1c to monitor long-term compliance to diet and drug therapy
Watch for hypoglycemia and hyperglycemia
Lessening Fingertip Pain From Testing
Don't use rubbing alcohol. Repeated use will thicken the skin. Instead, wash your hands in warm, soapy water prior to your fingerstick. Warm water will help you produce a better drop of blood. Once your finger is pricked, do not squeeze immediately. Instead, hang your hand down and let gravity do the work for you. Try 'milking' your finger prior to lancing. Excessive squeezing to get the blood to flow could cause bruising.
Try a shallower puncture. The deeper you lance, the more tissue you damage.
Try different lancets.Many lancets on the market are interchangeable with different lancing devices. Look for shorter and finer products and talk to your diabetes educator. It's better to 'spread the damage' over as many sites as possible instead of abusing that favourite spot. Target the sides of your fingers instead of the soft centre area where there are more nerve endings.
suggest clients go in a 'horseshoe' pattern around their fingertips.
Apply firm pressure at the site of the finger prick: using a tissue, for several seconds or until you have no more leakage. You want to make sure that the bleeding has completely stopped at the site to prevent bruising and further pain.
Canadian diabetes Association