Magnesium and Phosphorus

Question 1

What are the main causes of hypomagnesemia?

Answer 1

• loss via GI tract (diarrhea, malabsorption)
• loss via kidney
• lost in sweat (horses)
• grass tetany in ruminants

Question 2

What are the 2 main manifestations of hypomagnesemia?

Answer 2

• secondary hypokalemia due to renal wasting of K

- impaired PTH production and release, leading to hypocalcemia

Question 3

What are the clinical signs associated with hypomagnesemia?

Answer 3

• hyperexcitability
• tremors, ataxia
• frank tetany
• cardiac arrhythmias

Question 4

What are the causes of hypermagnesemia?

Answer 4

• only seen with compromised renal function

Question 5

What are the clinical signs of hypermagnesemia?

Answer 5

paresis
paralysis
heart dysfunction
GI upset

Question 6

What are possible causes of hypophosphatemia?

Answer 6

• primary hyperparathyroidism
• hypercalcemia of malgnancy
• vitamin D deficiency
• respiratory alkalosis
• decreased intestinal absorption of P
• renal tubular defects

Question 7

What is the most common cause of hyperphosphatemia?

Answer 7

• decreased GFR