Calcium Homeostasis

Question 1

Effects of loop diuretic on Ca?

Thiazidees?

Answer 1

Loops – Increase Excretion

Thiazides – Decrease Excretion

Question 2

Effects of PPIs and H2 antagonists on Ca

Answer 2

Decreased Absorption of CA

Question 3

Effects of carbemasepine, isoniazid, theophylline, and rifampin on Ca?

Answer 3

Induction of catabolic p450s

Question 4

Bisphosphonates inhibit ________ of osteoclasts

Answer 4

Farnesyl-PP synthesis

Question 5

Important adverse effects of Bisphosphonates

Answer 5

NVD, Musculoskeletal Pain
Osteonecrosis of the Jaw
Atypical Femur Fractures

Question 6

Which Bisphosphonates are approved for Paget’s, but not for Osteo

Answer 6

PAMIdronate
TILUdronate
ETIdronate

Question 7

Name the four bisphosphonates used for Osteoporosis

Ones with long chain and N

Answer 7

ZOLEdronate
ALENdronate
RISEdronate
IBANdronate

Question 8

What does it matter that Bisphosphonates inhibit farnesyl pyrophosphate synthase

Answer 8

Disrupts prenylation of proteins in osteoclasts

Question 9

Names and Role of Estrogens and SERMS in Osteoporosis treatment

Answer 9

Estradiol and Raloxifene (lower cancer, still stroke)
Prevent post-menopausal bone loss
Increases blast activity

Question 10

Names and Role of Calcitonin in treatment

Answer 10

Calcimar, Cibacalcin
Decreases osteoclast activity, blocks renal abs. of P and Ca
Pagets, Osteo over 5 years after meno, hypercalcemia of malignancy

Question 11

Side effects of calcitonin treatment

Answer 11

Urticaria, Hand Swelling, Nausea

Question 12

Mechanism of Teripartide? Who do you use it on?

Answer 12

AA 1-34 of Parathyroid Hormone
Given w/ Ca to stimulate osteoblast activity
Treat high fracture risks

Question 13

Side effects of Teripartide

Answer 13

Orthostatic Hypertension
Hypercalcemia
Arthralgia
Allergic Rxn

Question 14

Explain how PTH works in the context of RANKL and OPG

Answer 14

Continuous PTH increases RANKL and Decreases OPG, causing an increase in osteoclasts. Intermittent can upregulate OPG, which will bind RANKL and keep is from activating RANK and causing differentiation

Question 15

What drug would you use promarily for the bone formation phase?

Answer 15

PTH once daily

Teripartide

Question 16

Cons of teriparatide

Answer 16

Must be injected daily
Not recommended beyond 2 years
Risk of Bone Cancer

Question 17

How does Denosumab work?

Answer 17

Ab against RANKL, prevents osteoclast differentiation

High fracture risk post menopausal patients that can’t toleratate BPs

Question 18

Adverse effects of Denosumab?

Answer 18

Hypocalcemia, Musculoskeletal Pain
Osteonecrosis of the Jaw
Atypical Femur Fractures
Infections and Skin Rxns

Question 19

How does Cinacalcet work? When to use it?

Answer 19

Binds to calcium sensing receptor to inhibit PTH release to lower PTH and serum Ca
For hyperparathyroidism

Question 20

Significance of Zemplar and Hectorol

Answer 20

Vitamin D analogs used to treat hyperparathyroidism in CKD. They will inhibit PTH secretion with less Ca effect than normal D

Question 21

Important Phosphate Binders

Answer 21

Lanthanum Carbonate (Ca and P)
Sevelamer (Just P)