Drugs Affecting The Body System: Endocrine System PDF

***DRUGS AFFECTING THE BODY SYSTEM:*** ***Endocrine System*** ENDOCRINE SYSTEM - Consists of ductless glands that secretes into the bloodstream. HORMONE - Chemical substances synthesized from amino acids and cholesterol that act on body tissues and affect cellular activity. - PROTEIN...

***DRUGS AFFECTING THE BODY SYSTEM:*** ***Endocrine System*** ENDOCRINE SYSTEM - Consists of ductless glands that secretes into the bloodstream. HORMONE - Chemical substances synthesized from amino acids and cholesterol that act on body tissues and affect cellular activity. - PROTEINS/SMALL PEPTIDES- hormones from thyroid, parathyroid, growth hormone - STEROIDS- hormones from the adrenal glands and the gonads a. GROWTH HORMONE/SOMATOTROPIC HORMONE ====================================== - which stimulates growth in tissue and bone. - GH- Releasing Hormone (GH-RH)- somatropin - GH- Inhibiting Hormone (GH-IH)- somatostatin - Cannot be given orally (they are inactivated by GI enzymes), they are given SC or IM. DRUG THERAPY FOR GROWTH HORMONE DEFICIENCY ========================================== - GH acts on a newly forming bone, it must be administered before the epiphyses are fused. - Prolonged GH therapy can atagonize insulin secretion. - Somatropin- GH used to treat growth failure in children because of GH deficiency. - It has an identical amino acid sequence as human GH. - Contraindicated in pediatric patients who have growth deficiency due to severe obesity or in those who have severe respiratory impairment. ◆ Corticosteroid can inhibit the effects of somatropin - This drug can enhance the effects of antidiabetics and can cause hypoglycemia. - Somapacitan- recently approved by the FDA for adults with GH deficiency.  SIDE EFFECTS (Somatropin) - Paresthesia - Arthralgia - Myalgia - Peripheral edema - Weakness - Cephalgia - Glucose fluctuations - Hypothyroidism - Hematuria - Seizures - Intracranial hypertension - Secondary malignancy DRUG THERAPY FOR GROWTH HORMONE EXCESS ====================================== - Gigantism- excessive growth during childhood. - Acromegaly- excessive growth after puberty. - **Pegvisomant**- blocks GH receptor sites, preventing the abnormal growth by normalizing insulin-like growth factor 1(IGF-1) level; it is given by injection. - SIDE EFFECTS: Hyperhydrosis, cephalgia, and fatigue - ADVERSE EFFECTS: Chest pain, hypertension, elevated hepatic transaminases - **Lanreotide-** is an analogue of somatostatin that has actions similar to those of endogenous somastatin. - The effects of reduced GH are dose related and have a duration of at east 28 days after a single injection - Available in depot formulation and is administered deep in the SQ layer. - SIDE EFFECTS: diarrhea, abdominal pain, n/v, constipation, weight loss and flatulence - **Octreotide**- is a synthetic somatostatin-inhibiting secretion of GH - SIDE EFFECTS: Nausea, bloating, flatus - ADVERSE EFFECTS: cardiac toxicity- bradycardia and arrhythmia - **Bromocriptine Mesylate**- a dopamine agonists, inhibits the secretion of GH caused by pituitaty adenomas. - SIDE EFFECTS: GI symptoms- nausea, anorexia and xerostomia - ADVERSE EFFECTS: Cardiac toxicity- hypertension, MI and angina; - Should be discontinued if hypertension occurs due to pregnancy (preeclampsia, eclampsia, PIH). b. THYROID STIMULATING HORMONE/THYROTROPIC HORMONE ================================================== - Secreted in response to thyroid releasing Hormone (TRH) from the hypothalamus. - Stimulates the thyroid gland to release thyroxine (T4) and triiodothyronine (T3). c. ADRENOCORTICOTROPIC HORMONE (ACTH) ===================================== - The hypothalamus releases corticotropin-releasing factor (CRF), which stimulates the pituitary gland to secrete adrenocorticotropic hormone (ACTH)- which stimulates the release of: - Glucocorticoids (cortisol), mineralocorticoids (aldosterone), and androgen from adrenal cortex. - Catecholamines (epinephrine and norepinephrine) from the adrenal medulla. - **COSYNTROPIN-** is administered to establish the endocrine gland responsible for the inadequate serum cortisol. - Is only approved for diagnostic purposes and is less potent and less allergenic than corticotropin. - It stimulates the production and release of cortisol, costicoterone and androgens from the adrenal cortex. - It is administered via IM or IV routes. - Plasma cortisol level should be measured just before and 30 to 60 minutes after administration; normal reponse is the doubling of the basal cortisol level. SIDE EFFECTS; bradycardia, hypertension, sinus tachycardia and peripheral edema DRUG INTERACTIONS: - Caution is advised when administering cosyntropin in patients receiving diuretics- it can increase electrolyte loss. - Patients taking estrogens can have an abnormal decreased response to the ACTH stimulation test. - Available in a repository corticotropin injection (RCI), which is administered via IM or SQ routes - RCI controls the synthesis of ACTH from cholesterol, which stimulates adrenal glands in releasing its hormones. - RCI decreases the symptoms of MS during its exacerbation phase. - It should be tapered over a 2- week period for infantile spasms to avoid adrenal insuffiency. - Corticotropin + diuretics or piperacillin can decrease the serum K level - If the patient is taking a digitalis prep and hypokalemia is present, digitalis toxicity can result. - Persons with diabetes may need to increased Insulin and oral antidiabetic drugs- because ACTH stimulates cortisol secretion which increases the blood sugar level. a. ANTI DIURETIC HORMONE ======================== - promote water reabsorption from the renal tubules to maintain water balance in the body fluids - **Deficiency can lead to DIABETES INSIPIDUS**- large amounts of water are excreted by the kidneys. - Vasopressin (Pitressin) - Desmopressin acetate- - ADH is contraindicated in patients with moderate to severe renal disease and in patients with hyponatremia or a history of such. - SIDE EFFECTS: hyponatremia, cephalgia, dyspepsia, diarrhea and n/v ◼ Seizure my occur due to hyponatremia. SYNDROME OF INAPPROPRIATE ANTI DIURETIC HORMONE (SIADH) ======================================================= - Excessive secretion of ADH from the posterior PG which can lead to an excessive amount of water retention expanding the intracellular and intravascular volume. - Common causes: small cell carcinoma of the lung, stressors (pain, infection, anxiety, trauma) - Can be treated by: - Fluid restrictions - Hypertonic saline - Drugs DRUGS FOR SIADH =============== - Demeclocycline- a tetracycline antibiotic that can induce nephrogenic DI within 5 days of starting the treatment that is reversed in 2 to 6 days after cessation of treatment. - Common side effect is photosensitivity. - Dental discoloration and enamel hypoplasia can occur. - Vasopressin Receptor Antagonists (Vaptans) - Indicated for the treatment of euvolemic hyponatremia- their effects increase serum sodium and free water clearance. - Vaptans are contraindicated in patients with hypovolemia. - CONIVAPTAN- contraindicated in patients with corn allergy. - Complications are injection site reactions such as phlebitis, pain, edema and pruritus. - SIDE EFFECTS AND ADVERSE REACTIONS: orthostatic hypotension, syncope, hypertension, atrial fibrillation and electrolyte imbalances. - TOLVAPTAN- given orally - Should not be given to patients with alcoholism, hepatic disease and malnutrition. - SIDE EFFECTS AND ADVERSE REACTIONS- related to loss of fluids ( thirst, dry mouth, constipation, hyperglycemia, diziness and weakness). NURSING RESPONSIBILITIES (PG DRUGS) =================================== a. Monitor v/s. Increased PR and decreased BP can indicate fluid loss. b. Monitor urine output. c. Monitor blood sugar and electrolyte levels in clients taking growth hormone. Hyperglycemia can occur with increased doses. d. Advise the client to adhere to the drug regimen. Discontinuation such as Corticotropin can cause hypo function of the glands. e. GROWTH hormone should be administered before epiphysis are fused. f. Monitor patient's weight- check for edema if weight gain occurs. g. Instruct patient to decrease salt intake. B. THYROID GLAND ================ Three Hormones Produced and Released by the TG: 1. Triiodothyronine (T3) 2. Thyroxine (T4) 3. Calcitonin- regulates serum calcium THYROID GLAND DISORDERS ======================= a. Primary Cause- a thyroid gland disorder b. Secondary Cause- lack of TSH secretion (pituitary disorder) c. Tertiary Cause- lack of TRH (hypothalamus disorder) THYROID REPLACEMENT DRUGS ========================= a. **Levothyroxine-** drug of choice for the treatment of primary hypothyroidism. - It increases the levels of T4 and metabolically is deiodinated to T3 - Also used to treat simple goiter and Chronic lymphocytic (Hashimoto) Thyroiditis. - MOA- it increases metabolic rate, oxygen consumption, utilization and mobilization of glycogen stores. b. **Liothyronine-** a synthetic T3 with a biologic half-life of 2.5 days with rapid onset of action (within a few hours)- it is used as initial therapy for treating myxedema. - Indicated for use as replacement or supplemental treatment for hypothyroidism of any etiology. - Better absorbed from the GIT (over 95%) than levothyroxine ⚫ Available for oral or IV administration. c. **Dessicated Thyroid-** naturally occuring thyroid hormone from porcine thyroid glands. ⚫ It contains both levothyroxine and liothyronine. - Used to treat hypothyroidism due to thyroid atrophy, TH deficiency and goiter. d. **Liotrix-** mixture of levothyroxine and liothyronine NURSING RESPONSIBILITIES a. Monitor v/s. Tempt, HR and BP are usually decreased. b. Monitor ct's weight. Weight gain commonly occurs in ct. with hypothyroidism. c. Instruct ct to take the drug at the same time each day, preferably before breakfast. Food will hamper absorption rate. d. Instruct the ct to avoid foods that can inhibit thyroid secretion like strawberries, peaches, peas, cabbage, turnips, spinach, cauliflower and radishes. e. Advise the ct to check cautions on labels of OTC drug. Avoid OTC drugs that caution against use by persons with heart disease of thyroid disease. 2. HYPERTHYROIDISM ================== GRAVE'S DISEASE/THYROTOXICOSIS ============================== - most common type of hyperthyroidism due to hyper function of the TG. Signs and Symptoms - Tachycardia - Palpitations - Excessive perspiration - Irritability - Exophthalmus - Weight loss Heat intolerance TREATMENT - Surgical removal of a portion of the TG (subtotal thyroidectomy) - Radioactive iodine therapy - Anti thyroid drugs ANTITHYROID DRUGS ================= a. **THIOUREA DERIVATIVES (THIOAMIDES)**- drugs of choice used to decrease TH production. 1. Propylthiouracil (PTU) 2. Methimazole- 10 times more potent and has a longer t ½ than PTU - Euthyroid state is achieved in 2 to 4 months - It is the preferred antithyroid because of the less severe side effects. - Rapidly absorbed from the GIT. b. Strong Iodide Preparations ============================= - when used with oral anticoagulants (warfarin) can increase the coagulation effect. - When used with Insulin and oral antidiabetic\--decrease the effect of the ATH drug - Digoxin and lithium increase the action of thyroid drugs - Phenytoin increases serum T3 level NURSING RESPONSIBILITIES a. Monitor v/S. b. Teach signs and symptoms of hypothyroidism/hyperthyroidism. c. Advise client to avoid anti thyroid drugs if pregnant or breastfeeding. d. Advise client to contact physician if a fever and sore throat occur. A serious adverse effects of ATH drugs is AGRANULOCYTOSIS. e. Instruct the client to take the drug with meals to decrease GI symptoms for antithyroid drugs. f. Emphasize the importance of drug compliance. Abruptly stopping anti thyroid drugs could bring on THYROID CRISIS. g. Advise the client about the effects of iodine and its presence in iodized salt, shellfish and OTC cough medicines. C. PARATHYROID GLAND **PARATHYROID GLAND DISORDERS** a. HYPOPARATHYROIDISM ===================== - Damage to the parathyroid glands - Hypomagnesemia - Vitamin D deficiency- in case of hypocalcemia - Renal impairment - Diuretic therapy a.1 VITAMIN D ANALOGUES ======================= ◼Calcitriol ◼Ergocalciferol =========================== - SIDE EFFECTS: fatigue, weaknessm cephalgia, n/v, diarrhea, cramps, drowsiness, dizziness, metallic taste, lethargy, constipation, xerostomia. - PK: Well absorbed in the GIT, 99% CHON bound; t1/2 3-8 hours (adult), 27 hours (children); excreted in feces and urine. ⚫ PD: Onset: 2-6 hours; peak 3-6 hours; duration 3-5 days b. HYPERPARATHYROIDISM ====================== - Malignancies of the PTG - Hyperthyroidism - Prolonged immobility DRUGS USED FOR HYPERPARATHYROIDISM b.1 Calcitonin-salmon ======================================================== - Prevents bone loss and fractures, increases bone density, and alleviates pain due to fractures and bone metastasis. - Contraindicated in patients allergic to fish. - SIDE EFFECTS: allergic reactions, GI symptoms (N/V), cephalgia and hypocalcemia - ADVERSE REACTIONS: Tetany and seizures b.2 Calcimimetics ⚫ Cincalcet ============================= - Mimics calcium in circulation, increasing the sensitivity of the calciumsensing receptors of the cells of the parathyroid gland, thereby reducing PTH secretion, - Used in patients with hyperparathyroidism due to chronic renal disease,, parathyroid cancer and those who are unable to undergo parathyroidectomy. - Contraindicated to patients with hypocalcemia. b.3 Bisphosphonates =================== - Block osteoclast activities, thereby inhibiting mineralization or resorption of the bone, which may lessen osteoporosis caused by hyperparathyroidism. - Serum Ca concentration should be obtained and hypocalcemia must be corrected before biphosphonates therapy. ⚫ Alendronate ⚫ Etidronate ⚫ Ibandronate ⚫ Risedronate ====================================================== NURSING RESPONSIBILITIES a. Monitor the serum Ca level. b. Advise the client to check OTC drugs for possible Ca content esp if the client has an elevated serum Ca level. c. Instruct women to inform their physician about pregnancy status before taking calcitonin preparation. d. Advise the client to report s/sy of hypocalcemia/hypercalcemia. D. ADRENAL GLANDS ================= - composed of the adrenal medulla and adrenal cortex. - ADDISON'S DISEASE 1. decrease in corticosteroid secretion - CUSHING'S SYNDROME 2. Increase in corticosteroid secretion. TYPES OF CORTICOSTEROIDS 1. GLUCOCORTICOIDS/CORTISONE DRUGS =========================================================== - The most potent natural cortisol produced by the body and are influenced by ACTH. - Its functions include having an effect on the inflammatory response, metabolism, growth, and biorhythms. - Several routes of administration: oral, parenteral (IM or IV), topical ( creams, ointments and lotions), and aerosol (inhaler). SHORT ACTING GLUCOCORTICOIDS ============================ a. b. INTERMEDIATE ACTING GLUCOCORTICOIDS =================================== a. **Methylprednisolone**- for adrenal insufficiency; PB- uk, t 1/2 3-3.5 h b. **Prednisolone**- a potent steroid that can be inected into joints and soft tissue. PB: 7090%; t 1/2 2-4 h c. Prednisone- LONG ACTING GLUCOCORTICOIDS =========================== a. b. SIDE EFFECTS (Prolonged or high doses) - Increased blood sugar - Abnormal fat deposits in the face and trunk - Decreased extremity size - Muscle wasting - Edema - Sodium and water retention - Hypertension - Euphoria or psychosis - Thinned skin with purpura - Peptic ulcers - Growth retardation - Long term use of glucocorticoids can cause adrenal atrophy (loss of adrenal gland function). - **When drug therapy is discontinued, the dose should be tapered to allow the adrenal cortex to produce cortisol and other corticosteroids.** - Glucocorticoids increase the potency of drugs taken concurrently including aspirin and NSAIDS, thus increasing the risk of GI bleeding and ulceration. - Use of potassium wasting diuretics with glucocorticoids increases potassium loss, resulting in hypokalemia - Glucocorticoids can increase blood glucose levels, so insulin or oral diabetic drug dosage may need to be increased. 2. MINERALOCORTICOIDS ===================== - Promote sodium retention and potassium and hydrogen excretion in the renal tubules. - They maintain fluid balance by promoting reabsorption of sodium from the renal tubules. - The primary mineralocorticoid is ALDOSTERONE, which is controlled by the RAAS, Example: Fludrocortisone ======================== - is an oral mineralocorticoid that can be given with a glucocorticoid. - It mimics the action of endogenous aldosterone. - For adrenocortical insufficiency (Addison's disease) - In larger doses, it can inhibit endogenous hormone secretions of adrenal cortex and potuitary gland, causing a negative nitrogen balance; therefore a high protein diet is indicated. - Hypokalemia- may cause metabolic alkalosis, orthostatic hypotension, cardiac rhythm changes, weakness, anorexia and myalgia - Fluid overload - Hypertension NURSING RESPONSIBILITIES a. Administer glucocorticoids only as ordered. - Oral, IV, IM (not in the deltoid muscle), aerosol and topical - Rashes, infection, and purpura should be noted and reported. b. Observe for s/sy of hypokalemia such as, n/v, muscular weakness, abdominal distention, paralytic ileus and irregular heart rate. c. Advise the client to take the drug as prescribed. Instruct the client not to abruptly stop the drug because ADRENAL CRISIS can result.When discontinued, the dose is tapered over 1 to 2 weeks. d. Advise the client to eat foods rich in K such as fresh and dried fruits, vegetables, meat and nuts. e. Advise the client not to take cortisone prep (oral or topical) during pregnancy. f. Teach the client to report s/sy of drug overdose or cushing's syndrome. g. Instruct client to take cortisone prep at mealtime or with food. h.Instruct the client to avoid persons with respiratory infection since these drugs suppress