Endocrine, Diabetes, Metabolism

Question 1

You should measure this electrolyte when treating a patient who has Vit. B12 deficiency?

Answer 1

Potassium
Treatment with vitamin B12 in patients with moderate to severe megaloblastic anemia can cause hypokalemia, which can sometimes be very severe and life-threatening. Hypokalemia results following the uptake of potassium by newly forming red blood cells. Serum potassium levels should therefore be monitored during the first 48 hours.

Question 2

Does exogenous estrogen increase or decrease the needed dose for a patient being treated for hypothyroidism?

Answer 2

More than 99% of circulating thyroid hormone (T4, T3) is bound to plasma proteins, primarily thyroxine-binding globulin (TBG). Biologically active, free thyroid hormone is rapidly cleared by the kidneys, and binding proteins ensure that adequate hormone is available for delivery to the peripheral tissues. Elevated estrogen levels, as seen in pregnancy and patients taking oral contraceptives, stimulate hepatic synthesis of TBG. Patients with normal thyroid function can increase thyroid hormone production to saturate the additional protein binding sites, but those with primary hypothyroidism are unable to increase thyroid hormone synthesis; oral contraceptive use in these patients can induce a relative hypothyroid state.

Question 3

Conditions that increase TBG?

Answer 3

Estrogens
Acute hepatitis

Require increased levothyroxine in patients treated with for hypothyroidism.

Question 4

Conditions that decrease TBG?

Answer 4

Androgenic hormones
High-dose glucocorticoids/hypercortisolism
Hypoproteinemia (eg, nephrotic syndrome, starvation)
Chronic liver disease

Could lead to hypothyroidism condition.

Question 5

Patients being treated for hypothyroidism should manage their levothyroxine dose how when they find out they are pregnant?

Answer 5

current guidelines advise that the dose of levothyroxine be empirically increased by approximately 30% (eg, 2 additional levothyroxine doses weekly) at the time the pregnancy is first detected (Choices B and E). Subsequently, TSH should be measured every 4 weeks and the dose adjusted to maintain TSH within trimester-specific norms.

Question 6

Congenital Adrenal Hyperplasia

Answer 6

21-Hydroxylase Deficiency
Decreased sodium
Decreased glucose
Increased potassium
Increased 17-alpha-hydroxyprogesterone

Tx:

• Hydrocortisone for glucocorticoids
• Fludrocortisone for mineralcorticoids