ELECTROLYTES, MINERALS, TRACE ELEMENTS

Question 1

Dietary reference intake of sodium

Answer 1

2.3g or 100mEq

Question 2

Dietary potassium requirements

Answer 2

4700mg or 120mEq

Question 3

Dietary magnesium reference intake

Answer 3

Male
19–30 years : 400 mg
31+ years old : 420 mg

Female
19–30 year old: 310 mg
31+ year old: 320 mg

Question 4

Dietary phosphorus reference intake

Answer 4

700 mg

Question 5

Dietary reference copper intake

Answer 5

900mcg

Question 6

Dietary reference zinc intake

Answer 6

11mg

Question 7

Daily reference calcium intake

Answer 7

Male
19–70 yo: 1000 mg
71+ yo: 1200 mg

Female
19–50 yo: 1000 mg
51+ yo: 1200 mg

Question 8

Dietary reference magnesium intake

Answer 8

Male
2.3mg

Female
1.8mg

Question 9

Normal serum sodium

Answer 9

135–145 mEq/L (135–145 mmol/L)

Question 10

Noraml plasma osmolality

Answer 10

285–295 mOsm/kg.

Question 11

Medications that can cause hyponatremia

Answer 11

Drugs That Alter SODIUM and WATER Homeostasis:
Amiloride
Indapamide
Loop diuretics
Thiazide diuretics
Trimethoprim

Drugs That Alter WATER Homeostasis:

Stimulator of central ADH production or release
Antidepressants:
Monoamine oxidase inhibitors
Selective serotonin reuptake inhibitors
Tricyclic antidepressants (more common with amitriptyline, desipramine, protriptyline)

Antiepileptic drugs:
Carbamazepine
Oxcarbazepine
Valproic acid

Antipsychotic agents:
Phenothiazines (e.g., thioridazine, trifluoperazine)
Butyrophenones (e.g., haloperidol)

Antineoplastic agents:
Alkylating agents (cyclophosphamide, ifosphamide, melphalan)
Platinum (cisplatin, carboplatin)
Vinca alkaloids (more common with vinblastine and vincristine)
Others: levamisole, methotrexate
Cotrimoxazole (especially at high doses)
Opioid analgesics
3,4-methylenedioxymethylamphetamine
(MDMA; aka Ecstasy)

Enhancers of ADH effect
Antiepileptic drugs (primarily carbamazepine and lamotrigine)
Antineoplastic agents (mostly cyclophosphamide)
Nonsteroidal anti-inflammatory
drugs
Oral hypoglycemic agents:
Chlorpropamide
Tolbutamide

Drugs with unclear mechanisms
ACE inhibitors
Bromocriptine
Oxytocin
Venlafaxine

Question 12

Drugs That Can Cause Diabetes Insipidus
by Decreasing Renal Response to ADH

Answer 12

Amphotericin B
Cidofovir
Cimetidine
Clozapine
Colchicine
Conivaptan
Cyclophosphamide
Demeclocycline
Epirubicin
Ethanola
Fluvoxamine
Foscarnet
Gentamicin
Lithium
Methicillinb
Phenytoina (uncommon at therapeutic doses)
Propoxypheneb
Tolvaptan
Verapamil
Vinblastine

Question 13

Normal serum potassium

Answer 13

3.5 to 5.5mmol/L

Question 14

Normal chloride range

Answer 14

Normal range: 95–103 mEq/L (95–103 mmol/L)

Question 15

Normal serum magnesium range

Answer 15

1.7–2.4 mg/dL (0.7–0.99 mmol/L)
or 1.4–2 mEq/L

Question 16

Normal serum calcium range

Answer 16

9.2–11 mg/dL (2.3–2.8 mmol/L) for adults

Question 17

Normal range of serum ionized calcium

Answer 17

4–4.8 mg/dL or 1–1.2 mmol/L

Question 18

Normal phosphate levels

Answer 18

2.3–4.7 mg/dL (0.74–1.52 mmol/L) for
adults

Question 19

Normal urine calcium

Answer 19

<250 mg/day in men
<200 mg/day in women

Question 20

Normal serum PTH

Answer 20

10–65 pg/mL

Question 21

Normal urine phosphate

Answer 21

1 g/day (average)