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