Thyroid Drugs Flashcards
Which calcium compound requires stomach acid for absorption?
Calcium carbonate
What should be included in oral calcium preparations? Why?
Vitamin D
It increases intestinal absorption of Ca2+
Which is preferred: Calcium gluconate or calcium chloride? Why?
Calcium gluconate
It produces less venous irritation
What is the MOA of Ergocalciferol?
Vit D compound
- regulates absorption of Ca and PO4 from the small intestine
- Inhibits PTH synthesis and release
- Increases bone formation
What are the indications of ergocalciferol?
- Vit D-dependent rickets
- Hypocalcemia due to hypoparathyroidism
- Tetany
- Chronic renal dialysis
What are the contraindications of Ergocalciferol?
- Pregnancy
- History of renal stones
What are the SE of Ergocalciferol?
- GI:
- Metallic taste
- Vomiting
- CNS
- Weakness
- Headache
What side effect can occur when taking ergocalciferol with magnesium-containing antiacids?
hypermagnesemia
What side effect can occur when taking ergocalciferol with barbiturates?
Vitamin D deficiency
What side effect can occur when taking ergocalciferol with phenytoin?
Vitamin D deficiency
Ergocalciferol
- MOA
- IND
- SE
- CON
- MOA
- Vit D3 analog
- absorption of Ca and PO4 from intestines
- inhibits PTH
- Overall: increases Ca and bone formation
- IND
- Rickets
- Hypocalcemia from Hypoparathyroidism
- Tetany
- Chronic renal dialysis
- SE
- GI: metallic taste, vomiting
- CNS: weakness, headache
- CON
- pregnancy
- History of renal stones
What is the MOA of bisphosphonates?
- Inhibit mevalonate pathway in osteoclasts
- Slow or block bone resorption
- lower serum Ca lvls
Alendronate
- MOA
- IND
- SE
- CON
- MOA
- Bisphosphonate
- Inhibits mevalonate pathway in osteoclasts
- Slow or block bone resorption (lower serum Ca lvls)
- IND
- Osteoporosis
- Paget’s Disease
- SE
- Esophageal erosion in patients who cannot remain upright
- Initial increase in bone pain in Paget’s
- Nausea
- Diarrhea
- CON
- Pregnancy
- Renal dysfunction
- interfere with excretion
Etidronate
- MOA
- IND
- SE
- CON
- MOA
- Bisphosphonate
- Inhibits mevalonate pathway in osteoclasts
- Slow or block bone resorption (lower serum Ca lvls)
- IND
- Hypercalcemia of malignancy
- SE
- Esophageal erosion in patients who cannot remain upright
- Nausea
- Diarrhea
- CON
- Pregnancy
- Renal dysfunction
- interfere with excretion
Risedronate
- MOA
- IND
- SE
- CON
- MOA
- Bisphosphonate
- Inhibits mevalonate pathway in osteoclasts
- Slow or block bone resorption (lower serum Ca lvls)
- IND
- Osteoporosis
- Paget’s Disease
- SE
- Esophageal erosion in patients who cannot remain upright
- Initial increase in bone pain in Paget’s
- Nausea
- Diarrhea
- CON
- Pregnancy
- Renal dysfunction
- interfere with excretion
Pamidronate
- MOA
- IND
- SE
- CON
- MOA
- Bisphosphonate
- Inhibits mevalonate pathway in osteoclasts
- Slow or block bone resorption (lower serum Ca lvls)
- IND
- Paget’s Disease
- Hypercalcemia of malignancy
- Osteolytic bone lesions
- SE
- Esophageal erosion in patients who cannot remain upright
- Initial increase in bone pain in Paget’s
- Nausea
- Diarrhea
- CON
- Pregnancy
- Renal dysfunction
- interfere with excretion
Tiludronate
- MOA
- IND
- SE
- CON
- MOA
- Bisphosphonate
- Inhibits mevalonate pathway in osteoclasts
- Slow or block bone resorption (lower serum Ca lvls)
- IND
- Osteoporosis
- Paget’s Disease
- SE
- Esophageal erosion in patients who cannot remain upright
- Initial increase in bone pain in Paget’s
- Nausea
- Diarrhea
- CON
- Pregnancy
- Renal dysfunction
- interfere with excretion
Ibandronate
- MOA
- IND
- SE
- CON
- MOA
- Bisphosphonate
- Inhibits mevalonate pathway in osteoclasts
- Slow or block bone resorption (lower serum Ca lvls)
- (-) osteoclasts
- IND
- Osteoporosis
- SE
- Esophageal erosion in patients who cannot remain upright
- Initial increase in bone pain in Paget’s
- Nausea
- Diarrhea
- CON
- Pregnancy
- Renal dysfunction
- interfere with excretion
Zoledroic Acid
- MOA
- IND
- SE
- CON
- MOA
- Bisphosphonate
- Inhibits mevalonate pathway in osteoclasts
- Slow or block bone resorption (lower serum Ca lvls)
- IND
- Osteoporosis
- Paget’s Disease
- Hypercalcemia of malignancy
- Osteolytic bone lesion
- SE
- Esophageal erosion in patients who cannot remain upright
- Initial increase in bone pain in Paget’s
- Nausea
- Diarrhea
- CON
- Pregnancy
- Renal dysfunction
- interfere with excretion
What is the MOA of Calcitonin?
- Binds osteoclasts and raises cAMP
- inhibits bone resorption
- lowers Ca lvls
- Increased excretion of Ca, PO4, Na from kidney
What are the therapeutic uses of calcitonin?
- Osteoporosis
- only in women who can’t tolerate other treatments
- Paget’s Disease
- Hypercalcemia
What are the side effects of Calcitonin use?
- Flushing
- Rash
- Urinary frequency
- injection site inflammation
What are the contraindications of Calcitonin use?
- Could exacerbate:
- Renal dysfunction
- Pernicious anemia
- salmon/fish allergies (for salmon calcitonin)
Calcitonin
- MOA
- IND
- SE
- CON
- MOA
- Binds osteoclasts and raised cAMP
- bone resorption
- lowers Ca lvls
- Binds osteoclasts and raised cAMP
- IND
- Osteoporosis
- In women who can’t tolerate other treatments
- Paget’s Disease
- Hypercalcemia
- Osteoporosis
- SE
- Flushing
- Rash
- Urinary frequency
- CON
- Renal dysfunction
- Pernicious anemia
Raloxifene
- MOA
- IND
- SE
- MOA
- Estrogen agonist in bone
- Estrogen antagonist in endometrium and breast
- decreased cancer risk
- IND
- Osteoporosis in women with breast cancer or endometrial cancer
- SE
- venous thromboembolism
- increased hepatic sythesis of clotting factors
- venous thromboembolism
How do estrogens affect bone?
- suppresses transcription of IL-6
- induces osteoclast proliferation
- Osteoclast apoptosis
- Increased osteoblasts and osteocytes
Plicamycin
- MOA
- IND
- SE
- CON
- MOA
- inhibits osteoclasts
- block action of PTH
- interrupts DNA-directed RNA synthesis
- IND
- Paget’s disease
- Hypercalcemia
- SE
- Myelosuppression
- Coagulation disorders
- CON
Fluoride
- MOA
- IND
- SE
- MOA
- Mitogen for osteoblasts
- increases trabecular bone mass
- IND
- Possibly osteoporosis
- SE
- risk of osteosclerosis
Strontium ranelate
- MOA
- IND
- SE
- MOA
- decreases osteoclast, increases osteoblast activity
- marker for bone formation
- IND
- None in US
- SE
- Heart complications including heart attack
Why is Strontium ranelate not used in the US?
- SE: heart complications including heart attacks
What is the MOA of Parathyroid Hormone?
- MOA
- intermittent stimulation of bone cells increases remodeling with more bone formed than resorbed
Teriparatide
- MOA
- IND
- SE
- CON
- MOA
- intermittent stimulation of bone cells increases remodeling with more bone formed than resorbed
- IND
- Osteoporosis
- Postmenopausal
- In Men
- Osteoporosis
- SE
- CON
- those with risk of osteosarcoma
Denosumab
- MOA
- IND
- SE
- MOA
- Ab that inactivates RANK ligand
- Prevents recruitment and function of osteoclasts
- IND
- Osteoporosis
- SE
- musculoskeletal pain
- hypercholesterolemia
- cystitis
What is the MOA of Prednisone?
glucocorticoid: inhibits osteoblast activity
What are the clinical uses of Calcitriol?
- Secondary hyperparathyroidism
- Secondary hypoparathyroidism
- Rickets
- Osteoporosis
What is the drug of choice for thyroid hormone replacement?
Levothyroxine (T4)
What is the drug of choice for pituitary TSH suppressive therapy in patients with thyroid cancer?
Levothyroxine (T4)
What are the indications for Levothyroxine?
- Thyroid hormone replacement
- pituitary TSH suppresive therapy in patients with thyroid cancer
- Myxedema coma
What are the adverse effects of Liothyronine?
Adverse cardiac effects
(Cardiac arrest)
What is Liotrix?
Mix of both T3 and T4 synthetic hormones
(T4:T3 is 4:1)
What is the MOA of thioamines?
- Compete with thyroglobulin for oxidized iodide in the process of
- organification and
- coupling
- (both by thyroid peroxidase)
- Inhibits T4/T3 peripheral conversion
Propylthiouracil
- MOA
- IND
- SE
- MOA
- inhibits both:
- Thyroid peroxidase (organification)
- T4/T3 conversion (peripheral conversion)
- inhibits both:
- IND
- Hyperthyroidism
- Preferred in pregnancy
- SE
- depletes prothrombin (bleeding)
- liver injury
- transient leucopenia to severe agranulocytosis
- goiter
Methimazole
- MOA
- IND
- SE
- CON
- MOA
- Inhibits only thyroid peroxidase (organification)
- IND
- Hyperthyroidism
- SE
-
Bone marrow suppression
- requires transfusion
- Liver injury
- Goiter
-
Bone marrow suppression
- CON
- Pregnancy
To what is Carbimazole converted after absorption?
- MOA
- Converted to Methimazole after absorption
Which thyoamine is preferred for pregnant women?
Propylthiouracil
What is the Wolff-Chaikoff effect?
High levels of iodide inhibit thyroid synthesis and release
Potassium iodide
- MOA
- IND
- SE
- CON
- MOA
- Wolff-Chaikoff effect
- raises levels of iodide to inhibit TH synthesis
- Wolff-Chaikoff effect
- IND
- Acute thyrotoxicosis
- Radiation emergencies
- blocks thyroid function
- Thyroid surgery
- reduces syze and vascularity of the thyroid
- SE
- Hypothyroidism
- May worsen toxic goiter
- CON
What is the therapeutic use of thyrotropin alpha?
- Test thyroid function
- Thyroidectomy (Radioactive Iodine Ablasion)
- Increase TSH
- Increase radioactive iodine uptake
What is the MOA of radioactive iodide isotope 131I-?
- Emits ß-rays toxic to cell
- Enters follicular cells thru Na/I symporter
- Selective destruction of thyroid gland
What are the SEs of Radioactive iodide isotope 131 I-?
- Hypothyroidism
- Ophalmopathy in Grave’s disease
What are the contraindications of Iodide treatment (radioactive, potassium iodide, sodium iodide)?
- Pregnancy
- Breast-feeding
- enters breast milk
- Pulm edema
- TB
What is the MOA and therapeutic use of ß blockers such as propanolol?
- MOA:
- inhibits peripheral T4/T3 conversion
- IND
- Thyroid storm (Hyperparathyroidism)
Ipodate
- MOA
- IND
- MOA
- Radiocontrast
- Inhibits peripheral T4/T3 conversion
- IND
- Acute Graves disease (emergency situation)
- Acute thyroid storm (emergency situation)
Not FDA approved
What is the effect of Lithium on the thyroid? What can be a potential complication?
- Effect:
- inhibits TH release
- Complication:
- Hypothyroidism
Amiodarone
- MOA
- IND
- SE
- MOA
- Antiarrhythmic
- (-) 5’ deiodinase
- decreased peripheral conversion
- increased rT3
- IND
- Thyrotoxicosis
- Thyroiditis
- SE
- Hypothyroidism
- Metabolism releases iodide (can cause Wolff-Chaikoff effect)
- Hyperthyroidism
- in thyrotoxicosis and thyroiditis
- Hypothyroidism
What is the MOA of Corticosteroids regarding thyroid function?
Inhibit peripheral conversion ((-)5’ deiodinase)