Hypothyroidism 2 Flashcards
Which of the following is true about evaluation of Autoimmune hypothroidism
a. T3 measurements are not indicated
b. There may be decreased creatine phosphokinase
c. cholesterol and triglycerides may be decreased
d. microcytic anemia may be found
A
a. T3 measurements are not indicated
b. There may be increased creatine phosphokinase
c. cholesterol and triglycerides may increaed
d. normocytic or macrocytic anemia may be found
After RAI for hyperthyroidism , what is used to measure thyroid function
Because TSH levels are suppressed by
hyperthyroidism, unbound T4
levels
are a better measure of thyroid function
Responsible for the hypothyroidism that
occurs in up to 13% of patients treated with amiodarone
Iodine excess
If there is no residual thyroid function, the daily replacement
dose of levothyroxine is usually
1.6 μg/kg body weight (typically
100–150 μg)
In patients who develop hypothyroidism after the treatment of Graves’ disease, there is often underlying autonomous function, necessitating lower replacement doses of?
typically 75–125 μg/d
Adult patients under 60 years old without evidence of heart
disease may be started on what dose of levothyroxine
50–100 μg levothyroxine (T4) daily
When treating, who often should TSH be measured
2 months after instituting treatment
1,2,3,4, Mnemonic: TSH 2 month FT3 FT4
Drugs that interfere with T4 absorption or metabolism are the following except:
a. Bile acid sequestrants
b. Calcium supplements
c. Ranitidine
d. Ferrous sulfate
C.
bile acid sequestrants, ferrous sulfate, calcium supplements,
selevamer, sucralfate, proton pump inhibitors, lovastatin, aluminum
hydroxide, rifampicin, amiodarone, carbamazepine, phenytoin, and
tyrosine kinase inhibitors
When is levothyroxine recommended in cases of Subclinical hypothyroidism
If the patient
is a woman who wishes to conceive or is pregnant, or when TSH
levels are above 10 mIU/L
When TSH levels are below
10 mIU/L, a trial of treatment may be considered when
patients
have suggestive symptoms of hypothyroidism, positive TPO antibodies, or any evidence of heart disease
How is treatment of subclinical hypothyroidism started
Treatment is administered by starting with a low
dose of levothyroxine (25–50 μg/d) with the goal of normalizing
TSH
For hypothyroid women planning conception, what would be the target TSH be
<2.5 mIU/L for
hypothyroid women
How often should thryoid function be evaluated in pregnant hypothyroid women
- After pregnancy is confirmed
- Every 4 weeks
during the first half of the pregnancy,
with less frequent testing after
20 weeks’ gestation (every 6–8 weeks depending on whether levothyroxine dose adjustment is ongoing).