The Endocrine System

1. The Endocrine System • Consists of glands and other structures that produce hormones which are released into the circulatory system

2. The Endocrine System • Consists of glands and other structures that produce hormones which are released into the circulatory system • Regulation is established through hormones affecting target tissue

3. Regulation • Homeostatsis is achieved through feedback mechanisms • Negative feedback – negates change to bring levels back to normal

4. Pituitary Gland • Regulates other endocrine glands as well as other body activities

6. Anterior pituitary Hypo- thalamus - - Negative feedback Negative feedback Thyroid hormones osmolality TSH ADH Thyroid gland Water absorption + + Para- thyroids - Negative feedback - Pancreas Negative feedback calcium Insulin PTH Glucose Bone, GIT & Kidney Liver, fat & muscle + + Different hormones, different signals

7. Growth Hormone • Non-endocrine related disorders can also cause growth delay: • Intrauterine growth retardation, chromosomal defects, abnormal growth of cartilage or bone, poor nutrition, variety of systemic diseases

8. Growth Hormone • Deficiency of endogenous growth hormone causes growth retardation • Growth delay may be caused by • Family growth patterns, genetic disorders, malnutrition, systemic or chronic illness, psychosocial stress, or a combination of these • Endocrine deficiency, or problems with thyroxine, cortisol, insulin, or GH

9. Growth Hormone • Release of GH is stimulated by the release of GHRF secreted by the hypothalamus • GH is inhibited by • Glucocorticoids • Obesity • Depression • Progesterone • Hypokalemia • Altered thyroid function

10. Drug List Synthetic Human Growth Hormones • somatrem (Protropin) • somatropin (Humatrope)

11. Growth Hormone • The younger the patient at time of treatment the greater the height that may be achieved • Little response is seen after age 15-16 in boys and 14-15 in girls

12. Thyroid Gland • Produces hormones (T3 and T4) that stimulate metabolic activity of body tissues • Hypothalamus and pituitary glands work together to release TSH • TSH stimulates T3 and T4 release

13. Thyroid Hormone Feedback Loop • Thyroid hormones build up in the blood • Signals are sent to the hypothalamic-pituitary axis that adequate levels have been met • TSH levels decrease

14. Negative feedback - Anterior pituitary Thyroid hormones TSH Thyroid gland + Feedback

15. Hypothyroidism • Production of thyroid hormones is below normal • Cretinism occurs in children at birth due to inadequate maternal iodine intake • Can cause mental retardation, thick tongue, lethargy, lack of response, short stature – can be corrected if treated

16. Primary Thyroid disease Secondary Thyroid disease Primary and secondary disorders

18. Apathy Constipation Decreased heart rate Depression Dry skin, nails, and scalp Easy fatiguing Enlarged thyroid Lowered voice pitch Myxedema Puffy face Reduced mental acuity Swelling of eyelids Tongue enlarged and thickened Weight gain Hypothyroidism Symptoms

19. Causes of Hypothyroidism • Autoimmune destruction of the gland • Radioactive iodine therapy • Surgical removal of the gland

20. Treatment for Hypothyroidism • Thyroid replacement therapy • Should not be used to treat obesity

21. Drug List Agents for Hypothyroidism • levothyroxine, T4 (Levothroid, Levoxyl, Synthroid) • liothyronine, T3 (Cytomel) • liotrix (Thyrolar) • thyroid (Armour Thyroid)

22. levothyroxine, T4 (Levothroid, Levoxyl, Synthroid) • Used for chronic therapy • Can be cardiotoxic • Alters protein binding of other drugs • Should not switch brands once stabilized

23. levothyroxine Dispensing Issues • Can be cardiotoxic; report any of the following: • Chest pain, increased pulse, palpitations, heat intolerance, excessive sweating Warning!

24. levothyroxine Dispensing Issues • Look-alike and Sound-alike Drugs: • levothyroxine (thyroid replacement) • levofloxacin (antibiotic) Warning!

26. Hyperthyroidism • Excessive thyroid hormone • Most common cause is Grave’s disease • Other causes: • Excessive exogenous iodine • Thyroid nodules • Tumor in the pituitary causing overproduction of TSH

28. Symptoms of Hypterthyroidism • Decreased menses • Diarrhea • Exophthalmos • Flushing of the skin • Heat intolerance • Nervousness • Perspiration • Tachycardia • Weight loss

29. Drug List Agents for Hyperthyroidism • methimazole (Tapazole) • propylthiouracil, PTU • radioactive iodine, 131I

31. Discussion What are the treatment options for hyperthyroidism?

32. Discussion What are the treatment options for hyperthyroidism? Answer: in children: surgery and hormone replacement; adults: surgery or medications

33. Diabetes/Hypoglycemic Agents • In the islets of Langerhans, in the pancreas, there are two primary specialized cells • Alpha Cells • Beta Cells

34. Hypoglycemic Agents • In the islets of Langerhans, in the pancreas, there are two primary specialized cells • Alpha Cells • Produce glucagon and raise blood glucose levels • Beta Cells

35. Hypoglycemic Agents • In the islets of Langerhans, in the pancreas, there are two primary specialized cells • Alpha Cells • Produce glucagon and raise blood glucose levels • Beta Cells • Produce insulin and lower blood glucose levels

37. Insulin • Helps cells burn glucose for energy • Works with receptors for glucose uptake • Enhances transport and incorporation of amino acids into protein • Increases ion transport into tissues • Inhibits fat breakdown

38. Diabetes • Caused by inadequate secretion or utilization of insulin • Leads to excessive blood glucose levels • Normal: 100 mg/dL

39. Type I Diabetes • Occurs most commonly in children and young adults • Average age of diagnosis is 11 or 12 • Patients are insulin dependent and have no ability to produce insulin on their own • May be due to an autoimmune response • Type I accounts for 5-10% of diabetic population

40. Type II Diabetes • Affect 80-90% of diabetics • Most patients are over 40 and more women than men are affected • Could be caused by insulin deficiency or insulin receptor resistance • Many of these patients are overweight and can treat their diabetes with weight loss

41. Gestational Diabetes • Occurs during pregnancy • Increases risk of fetal morbidity and death • Onset is during the 2nd and 3rd trimesters • Can be treated with diet, exercise, and insulin • 30-40% of women with gestational diabetes will develop type II in 5-10 years

42. Secondary Diabetes • Caused by medications • Oral contraceptives • Beta blockers • Diuretics • Calcium channel blockers • Glucocorticoids • phenytoin • May return to normal when drug is stopped

43. Symptoms of Diabetes • Frequent infections • Glycosuria • Hunger • Increased urination and nocturia • Numbness and tingling • Slow wound healing • Thirst • Visual changes • Vomiting • Weight loss, easy fatigability, irritability, ketoacidosis

44. Complications of Diabetes • Retinopathy leading to blindness • Neuropathy • Vascular problems can lead to inadequate healing which could lead to amputation • Dermatologic involvement • Nephropathy is the primary cause of end-stage renal disease

45. Lack of Insulin Activity • Diabetics cannot use glucose therefore their bodies metabolize fat • Gluconeogenesis is the formation of glucose from protein and fatty acids • Fatty acid is oxidized into ketones

46. Ketones • Strong acids • Cause the body pH to drop • Excreted in the urine or eliminated through respiration • Causes a fruity acetone smell on the breath that can be mistaken for alcohol

47. Treating Diabetes • Treatment consists of diet, exercise, and medications • Blood glucose monitoring must be done regularly throughout the day • Type II diabetics may be able to control the disease through diet and exercise alone

48. Treatment for Type II • Lifestyle changes • Oral monotherapy • Combination oral therapy • Oral drug plus insulin • Insulin only

49. Attention to diet Blood pressure control Compliance with medications Control of hyperlipidemia Daily foot inspections Increased physical activity Recognizing hypoglycemia Blood glucose testing Monitoring in the Dr’s office Patient education Prompt treatment of infections Setting goals General Treatment Guidelines

50. Drug List Drug for Lower Extremity Diabetic Ulcers • becaplermin gel (Regranex)