The Endocrine System

1. The Endocrine System

2. 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

3. 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

4. Hormones of pituitary gland

5. Deficit of GH

6. Overproduction of GH

10. Posterior pituitary hormones

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

12. 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

13. 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

14. 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

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

16. 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

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

19. 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

20. Struma (goiter) and hyperthyroidism Hypothyroidism Thyrotoxicosis

22. Congenital hypothyroidism(physical and mental retardation – nanism - pygmy, idiotism

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

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

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

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

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

29. 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

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

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

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. Insulin • Administered subcutaneously due to degradation in the GI tract • Different types of insulin have different onset of action times and duration of action times

40. Insulin Duration of Action

41. Insulin Dispensing Issues • It is very easy to grab the wrong insulin in the refrigerator • Always double-check yourself • They look exactly alike Warning!

42. Insulin administration sites should be rotated

43. Hypoglycemia • Blood glucose levels of <70 mg/dL • Can be caused by • Skipping meals • Too much exercise • Poor medication regimen • Certain drugs

44. Confusion Double vision Headache Hunger Numbness and tingling in mouth and lips Nervousness Palpitations Sweating Thirst Visual disturbances Weakness Signs & Symptoms of Hypoglycemia

46. insulin glargine (Lantus) • Synthetic long-acting insulin • Absorbed slowly and works over a 24-hour time period • Works similarly to physiologic insulin release

48. Drug List Human InsulinsMixtures • insulin aspart w/ protamine-insulin aspart (NovoLog Mix 70/30) • insulin lispro w/ protamine-insulin lispro (Humalog Mix 75/25) • insulin with zinc (lente) (Humulin L) • NPH-regular insulin (Humulin 70/30)

50. Drug List Oral Hypoglycemic Agents First- Generation Sulfonylureas • chlorpropamide (Diabinese) • tolbutamide