Anterior Pituitary - Pharm

principal for thyroid replacement agents

start low and go slow

levothyroxine

T4 thyroxine, synthetic. most common, long half life ~7 days, takes several weeks to achieve therapeutic blood level, can’t give loading dose, 99% protein bound

desiccated thyroid/Armor Thyroid

contains T3 & T4, from a bovine source, foreign animal protein = higher change to develop antibodies against it

liothyronine

T3/triiodothyronine. short acting, IV, used in emergencies/myxedema coma

side effects of thyroid replacement agents

hyperthyroidism: insomnia, unexplained weight loss, tachycardia, HTN

nursing implications for thyroid replacement agents

pts start on low dose, monitor VS - apical pulse before giving (HR above 100, hold and call provider), monitor labs as ordered (TSH, T4, maybe T3) usually 6-8 weeks after a dosage change then an annual lab review

pt education for thyroid replacement agents

take in AM on empty stomach to improve absorption, teach s/sx of under dose and excess dose, levels will be monitored, lifelong therapy, may take weeks/months to feel full benefits, do not switch brands/manufacturers - different bioavailabilities

treats hyperthyroidism

antithyroid agents - short term before thyroidectomy, iodine preparations, surgical removal

antithyroid agents 

methimazole, propylthiouracil (PTU). used before thyroid surgery to reduce vasculature of the gland. side effects: potentially fatal granulocytopenia - monitor WBC/fever/signs of illness. take with meals to prevent GI upset. Do not affect C cells.

methimazole

decreases vasculature of thyroid, inhibits synthesis of thyroid hormone. contraindicated with pregnancy b/c causes birth defects

propylthiouracil (PTU)

decreases vasculature of thyroid, inhibits synthesis and conversion of T4 to T3 in the peripheral tissues. has a black box warning b/c can cause severe liver damage, only used if Pt isn’t qualified for other drugs, recommended for women in 1st semester of pregnancy.

High concentrations of iodine…

interfere with thyroid hormone synthesis and treat hyperthyroidism

non-radioactive iodine = Lugol’s iodine = Potassium iodine

suppresses thyroid hormone synthesis. side effects: metallic taste, GI discomfort, stains teeth. Dilute in juice to mask taste, use a straw.

radioactive iodine (RAI-131)

can treat hyperthyroidism and thyroid cancer - large doses destroy thyroid tissue (thyroid ablation). side effects: all patient body fluids radioactive for 11 days, slight sore throat, must be isolated to minimize exposing others to radiation. avoid children, pregnant women, pets, double flush the toilet

Drugs for adrenal cortex disorders

Glucocorticosteroids, mineralcorticoids

treatment of addison’s

lifelong therapy with prednisone or cortisone

glucocorticosteroids

suppress histamine release, suppress inflammation, suppress immune response

short acting: cortisone, hydrocortisone

intermediate acting: prednisone, methyprednisolone

long acting: bethamethasone, dexamethasone

cushingoid side effects of glucocorticosteroids

cataracts, ulcers, gastric bleeding, thinning and bruising of skin, hypertension, hirsutism, infection, necrosis of femoral head, glycosuria, obesity, osteoporosis, immunosuppression, diabetes. weight gain with abnormal fat distribution - moon face, buffalo hump

sudden withdrawal of glucocorticosteroids can cause…

cardiovascular collapse

nursing implications for glucocorticosteroids

give in morning with food to mimic natural timing of steroid release and prevent GI upset, monitor labs - BMP, CBC for signs of infection, bleeding, hyperglycemia, V/S and weight for fluid retention, altered metabolism. pt’s with addison’s during periods of stress (like an acute infection) may need to increase their dosage and gradually taper down to their regular dose to mimic the body’s natural response to stress

pt teaching for glucocorticosteroids

take exactly as prescribed, sx of infection may be masked - report low grade fever sx of infection, take in morning with food, never stop taking abruptly, report increased stress, monitor blood sugar with long term therapy, report black tarry stools - GI bleeding

mineralcorticoids

fludrocortisone - synthetic aldosterone (reabsorb Na and water and excrete K) replacement therapy for addison’s

side effects for fludrocortisone

F&E imbalances

nursing implications & pt teaching for fludrocortisone

assess for s/sx of fluid retention (BP, weight gain, edema, SOB), labs - Na and K. S/sx of inadequate dose: too low = low BP, dehydration, too high = fluid excess, report signs of edema, eat high K foods and avoid high Na foods, dosage adjustment when under stress, never stop taking abruptly - can cause addison’s crisis.

for growth hormone deficiency

somatotropin

for growth hormone excess

octreotide (Sandostatin)

somatotropin

risk for developing diabetes due to the effect GH has on glucose metabolism

nursing implications for somatotropin

only given to pts before epiphyses have sealed, if after = will cause acromegaly, often used for severe watery diarrhea that isn’t responding to other treatments = decreases transit time in GI system, allows F&E to be reabsorbed, monitor BS levels, monitor height/weight charts. teaching: how to administer injections, monitor BS for risk of developing diabetes