Magnesium

Question 1

What is the 4th most abundent cation in the body?

Answer 1

Magnesium

Question 2

How often can you repeat doses of calcium?

Answer 2

every hour

Question 3

What is the clinical effect like?

Answer 3

immediate, but transient

Question 4

What does IV calcium do?

Answer 4

it directly antagonizes the NM and CV effects of hypermagnesemia

Question 5

How do you treat a patient with severe hypermagnesemia?

Answer 5

with IV calcium

Question 6

How can most cases of hypermagnesemia be anticipated?

Answer 6

renal failure patients should not be given mg meds, parenteral mg should be monitored

Question 7

When do you see muscle paralysis, respiratory paralysis, cardiac arrest?

Answer 7

above 10

Question 8

When do you see bradycardia, ecg changes, hypotension?

Answer 8

10-Jun

Question 9

When do you see drowsiness, flushing and headache?

Answer 9

mg- 4-6

Question 10

What 3 symptoms can be seen if potassium exceeeds 4 meq/L?

Answer 10

NM, CV, hypocalcemia

Question 11

How can mild hypermagnesemia occur?

Answer 11

hyperparathyroidism, hypothyrodism, diabetic ketoacidosis, tumor lysis syndrome, theophylline intoxication, lithium ingestion, dead sea water poisoning

Question 12

Where is the magnesium absorbed with magnesium enemas?

Answer 12

in the large bowel

Question 13

Other than giving a massive dose, how else can mg be increased orally?
Give an example of these disorders

Answer 13

by a GI disorder that enhances magnesium absorption

ulcer disease, gastritis, colitis

Question 14

What Is the 2nd most prevalent intracellular cation?

Answer 14

Magnesium

Question 15

What are two ways patients can be given exogenous magnesium?

Answer 15

laxatives and antacids

Question 16

What is the level for patient with end stage renal disease?

Answer 16

2.4-3.6

Question 17

What is considered hypermagnesemia?

When is this usually seen?

Answer 17

> 2.1

impaired renal function, large doses of magnesium given iv, orally or as an enema

Question 18

What can larger doses of mg precipitate?

Answer 18

diarrhea which exacerbates hypomagnesemia

Question 19

When should IM be used?

How should they be diluted?

Answer 19

only if IV is limited access and severe hypomagnesemia

20% before injection to prevent venous sclerosis and pain

Question 20

What is the IV bolus administration associated with?

Answer 20

flushing, sweating, and sensation of warmth

Question 21

How much should you use for non life threatening?

Answer 21

1 Meq/kg

Question 22

How much should you use for life threatening symptoms?

Answer 22

2g MgSO4

Question 23

What does magnesium replacement depend on?

Answer 23

the severity of the clinical manifestation

Question 24

give examples of NM?

Answer 24

weakness, seizures, tetany, coma, depression, tremor, spasm

Question 25

Why is magnesium important?

Answer 25

it is a cofactor required for nearly all biochemical and enzyme systems

Question 26

What are the dominant organ systems involved in hypomagnesemia?

Answer 26

NM nad CV

Question 27

What is symptomatic hypomagnesemia often associated with?

Answer 27

multiple electrolyte abnormalitites including hypokalemia, hypocalcemia, and metabolic alkalosis

Question 28

What do nephrotoxins do? | Which medications are included in this?

Answer 28

produce urinary magnesium wasting aminoglycosides, antibiotics, cisplatin, amphotericin B, cyclosporine, foscarnet, tacrolimus, and pentamidine

Question 29

What does hypovolemia do?

Answer 29

stimulates proximal sodium, water, and magnesium reabsorption

Question 30

What are examples of diuretics? | How do they do this?

Answer 30

loop and thiazide diuretics | inhibit mg reabsorption, produce mild hypomagnesemia

Question 31

Name two classes of drugs that can cause mg loss?

Answer 31

diuretics, and nephrotoxins

Question 32

What is one other way mg can be lost?

Answer 32

drugs

Question 33

What are examples of hormone induced renal loss?

Answer 33

hyperparathyroidism, hyperthyroidism, aldosteronism, hungry bone syndrome

Question 34

What are examples of tubular disorders?

Answer 34

postobstructive diuresis, renal tubular acidosis, Bartters syndome, primary renal magnesium wasting, glomeruloneprhitis

Question 35

What reactions is it involved in?

Answer 35

transfer of phophate groups, all reactions that require ATP, replication and transcription of DNA and the translation of mRNA

Question 36

How man Meq does a 70-kg adult have of Mg?

Answer 36

2000

Question 37

What are the two groups of renal losses?

Answer 37

primary tubule disorders, hormone induced renal losses

Question 38

give examples of GI losses?

Answer 38

prolonged nasogastric suctionling, acute and chronic diarrhea, malabsorption syndromes, extensive bowel resection, alcoholism, intestinal fistule, malabsorption,

Question 39

What are the 2 major mechanisms by which hypomagnesemia can be induced?

Answer 39

gastrointestinal or renal losses

Question 40

Where does hypomagnesemia occur commonly?

Answer 40

in inpatient settings

Question 41

What is classified as hypomagnesemia?

Answer 41

<1.4 Meq/L

Question 42

what does hypomagnesemia do?

Answer 42

stimulates transport

Question 43

How much is in the bone?

Answer 43

50-60%

Question 44

How much of extracellular magnesium accounts for the total body magnesium?

Answer 44

1%

Question 45

What does hypermagnesemia do

Answer 45

inhibits loop transport

Question 46

what is a major regulator of magnesium reabsorption?

Answer 46

the plasma concentration

Question 47

Where does 15-25% of magneisum get reabsorbed?

Answer 47

in the proximal tubule

Question 48

where does 60-70% of magnesium get absorbed?

Answer 48

in the thick ascending loop of henle

Question 49

Where is homeostasis regulated?

Answer 49

in the kidney through glomerular filtration and reabsorption

Question 50

How much of the ingested magnesium is absorbed in the small bowel?

Answer 50

30-40%

Question 51

What does magnesium balance depend on?

Answer 51

GI absorption and renal excretion

Question 52

What are the normal serum magnesium concentrations?

Answer 52

1.4-2.1 meq/L