Thyroid Hormone Replacement

Use: DOC hypothyroidism, non-endemic goiter, hashimoto's, thyrotropin dependnt thyroid carcinoma

Mechanism: Na salt of T4, may produce normal levels of T3 and T4

Side effects: Hyperthyroidism effects; 

Dx must be carefully titrated to the individual

TSH levels should be measured 4 to 6 weeks after adjusting the dose of T4

Other drugs: Liothyronine sodium (Cytomel^®) short half life and duration of action

Liotrix (Euthroid^®, Thyrolar^®) - 4:1 ration T4:T3, no benefit; may cause cardiac palpitations, tachy, weight loss, insomnia

Inhibitor of Thyroid hormone synthesis

Use: Graves disease, for pts that can't tolerate methimazole, used in early pregnancy (methimazole = teratogenic_

Mechanism: Decreases synthesis and release of T4; blocks conversion of T4 to T3

Effects are gradual (use B-blockers) as circulating T3/T4 last a week or so 

Side effects: itching, rash, sore throat, granulocytopenia, agranulocytosis

Adverse: black box warning, severe liver injury/acute liver failure

Other drug: Methimazole (Tapazole^®) - DOC for graves now!; more potent

Inhibitors of Thyroid Hormone synthesis

Use: Graves disease? Prior to thyroid Sx, decreases vascularity to thyroid; prevent uptake of radioactive iodine in the event of accident where large quantitis of the radioctive compound might be released

Mechanism: decreases T4 and T3; causes rapid decrease in release of thyroid hormone

Effects wear off after 2-8 weeks

Inhibitor of Thyroid Hormone Synthesis

Destroys thyroid gland in pts

Use: Graves disease; hyperthyroid in elderly with heart disease; diagnostic procedures; thyroid ablation

B-adrenergic Blocking Agent

Use: blocks symptoms of hyperthyroidism; used to prep for Sx while radioactive iodine takes effect

Also decreases peripheral conversion of T4 to T3 by liver, reducing potency of thyroid hormone

Contraindications: obstructive airway disease; asthma; caution in DM

Mechanism: inhibition of PTH secretion

Use: osteoporosis: Ca alone can't prevent osteoporosis, but adequate Ca is needed for any other Tx to work

Mechanism: Increases GI Ca and phosphate absorption; Vit D must be adequate for optimal absorption of Ca

Use: Vit D def, Rickets, Familial hypophosphatemia, hypoparathyroidism, osteomalacia

Hormone Drug

Use: Osteoporosis, prevent vertebral compression fractures

Mechanism: inhibits bone resorption of Ca and phosphate by osteoclasts; antagonizes the actions of PTH

PHK: intranasally or injected

Adverse: Allergic reactions, rhinitis, sinusitis, nasuea vomiting

Hormone drug

Use: Osteoporosis, the only anabolic osteoporosis therapy; hypoparathyroidism

Mechanism: recombinant PTH; causes intermittent spikes of PTH

Contraindications: osteosarcoma

Hormone Drug

Use: Osteoporosis

Hormone Drug

Use: Osteoporosis

Rank-Ligand inhibitors

Use: Severe osteoporosis in postmenopausal women; increase bone mass and strength in both cortical and trabecular bone

Mechanism: antibody to RANK-ligand, the factor made by osteoblasts that is necessary for the formation of mature osteoclasts

Contraindications; hypocalcemia, pregnancy category X

Biphosphate

Use: First line Osteoporosis in men and post-menopausal women

Mechanism: inhibits osteoclast activity and bone resorption; binds Ca salts, replacing phosphate and blocking hydroxyapatite

PHK: absorption is very poor

Adverse: Abdominal pain, upper GI irritation, esophageal ulceration, constipation, diarrhea, flatulence; renal tox if given too fast

Other drugs: Etidronate (Didronel^®)

Pamidronate (Aredia^®)

Ibandronate (Boniva^®)

Risedronate (Actonel^®, Atelvia^®)

Zoledronic acid (Reclast^®)

Calcium receptor agonist

Use: Osteoporosis

Mechanism: calcimimetic and blocks PTH release