Download Thyroid Cases

Thyroid Cases
MEGAN CHAN, PGY-1
UHCMC 2015
Guess the Diagnosis?
TSH
Free T4
T3
Diagnosis
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Primary hyperthyroidism
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Central hyperthyroidism
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Normal
Normal
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Normal
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T3 thyrotoxicosis
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↓
↓
Primary hypothyroidism
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↓
↓
Central hypothyroidism
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Normal
Normal
Subclinical hypothyroidism
Normal
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↑
Exogenous thyroid hormone
Subclinical hyperthyroidism
Case 1
44 y/o male is involved in a motor vehicle collision and sustains
multiple injuries to the face, chest and plevis. He is
unresponsive on the field and is intubated for airway protection.
Pt is admitted to the ICU, stabilized and undergoes successful
open reduction & internal fixation of the right femur and right
humerus. After he returns to the ICU, his TSH is 0.3 mU/L and
the total T4 level is normal. T3 is 0.6 μg/dL.
What is the most appropriate next management step?
A. Initiation of levothyroxine
B. Radionucleotide uptake scan
C. Thyroid ultrasound
D. Observation
E. Initiation of prednisone
Case 1
What is the most appropriate next management step?
A. Initiation of levothyroxine
B. Radionucleotide uptake scan
C. Thyroid ultrasound
D. Observation
E. Initiation of prednisone
Sick-euthyroid syndrome can occur in any acute, severe illness.
TSH/T4/T3 abnormalities are thought to result from release of
cytokines in response to severe stress. The most common hormone
pattern is low total and unbound T3 as peripheral conversion of T4 to
T3 is impaired. This is thought to be evolutionarily helpful as
lowering the most active thyroid hormone would limit catabolism in
starved or ill patients. T4 may be decreased in very sick patients.
Thyroid function will return to normal in weeks to months as the
patient recovers.
Case 2
29 y/o woman presents to your clinic complaining of difficulty
swallowing, sore throat, and tender swelling in her neck. She
has also noted fevers intermittently over the past week. Several
weeks prior to her current symptoms she experienced symptoms
of an URI. She has no PMHx. On exam, she is noted to have a
small goiter that is painful to the touch. Her oropharynx is
clear. Labs show WBC of 14.1 with normal diff, ESR 53, TSH of
21. Thyroid antibodies are negative.
What is the most likely diagnosis?
A. Autoimmune hypothyroidism
B. Cat-scratch fever
C. Ludwig’s angina
D. Subacute thyroiditis
Case 2
What is the most likely diagnosis?
A. Autoimmune hypothyroidism
B. Cat-scratch fever
C. Ludwig’s angina
D. Subacute thyroiditis
What is the most appropriate treatment for this
patient?
A. Iodine ablation of the thyroid
B. Large doses of Aspirin
C. Local radiation therapy
D. No treatment necessary
E. Propylthiouracil
Case 2
What is the most appropriate treatment for
this patient?
A. Iodine ablation of the thyroid
B. Large doses of Aspirin
C. Local radiation therapy
D. No treatment necessary
E. Propylthiouracil
Subacute Thyroiditis
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Aka Quervain’s thyroiditis, granulomatous thyroiditis, viral thyroiditis
Presents with fever, constitutional symptoms, & painful enlarged thyroids.
Peak incidence: 30-50 y/o, females > males
Multiple viruses have been implicated, but none identified as the trigger
3 phase illness:
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1st– Thyroid inflammation  follicle destruction  release of thyroid hormones 
Thyrotoxicosis
 Low TSH, high T4 & T3, radioiodine uptake is low/undetectable.
2nd—Thyroid is depleted of hormone  Hypothyroidism
 Elevated TSH, low free T4, radioiodine uptake returns to normal.
3rd—Recovery phase: decreased inflammation  follicles heal & regenerate thyroid
hormone (4-6 months later)
 Usually self-limited, benign
 Treatment:
 Mild sxs: Large doses of Aspirin (600mg q4-6hrs), NSAIDs
 Severe sxs: Steroid taper
 May require low-dose levothyroxine
Case 3
62 y/o man presents to the ED with chest pressure and
feeling “like my heart is fluttering inside my chest.” He
experienced similar symptoms 1 month ago that
resolved spontaneously. He did not seek medical
attention at that time. He has no significant PMHx.
On ROS he notes some recent weight loss despite an
increase in appetite and excessive sweating. On exam,
HR is irregular at 140-150 beats/min. BP is 135/55. He
is admitted and screening tests reveal and
undetectable TSH level.
Case 3
Which of the following statements is true?
A. 50% of hyperthyroid patients will convert from Afib to
NSR with thyroid management alone.
B. A firm, small thyroid on exam would be compatible
with a diagnosis of Graves’ disease.
C. Afib is the most common cardiac manifestation of
hyperthyroidism.
D. His excessive sweating is likely not related to
hyperthyroidisim.
E. Hyperthyroidism leads to a high-output state for the
heart, narrowing the pulse pressure.
Case 3
Which of the following statements is true?
A. 50% of hyperthyroid patients will convert from Afib to NSR
with thyroid management alone.
B.
A firm, small thyroid on exam would be compatible with a diagnosis of
Graves’ disease.
C.
Afib is the most common cardiac manifestation of hyperthyroidism.
D. His excessive sweating is likely not related to hyperthyroidisim.
E.
Hyperthyroidism leads to a high-output state for the heart, narrowing the
pulse pressure.
Common signs of thyrotoxicosis include tachycardia (most common cardiac
abnormality), Afib, tremor, goiter, and warm, moist skin. Common
symptoms include hyperactivity, dysphoria, irritability, heat intolerance,
excessive sweating and fatigue. Weight loss occurs frequently; however, some
pts will gain weight as they typically have marked increase in appetite. The
arrhythmias are a manifestation of a high-output state, which frequently leads
to a widened pulse pressure and a systolic murmur. This can exacerbate
underlying heart failure or CAD.
Case 3
The same patient is started on atenolol and his heart
rate slows to 80 beats/min.
Which of the following additional therapies is
most indicated?
A. Diltiazem
B. Methimazole
C. Levothyroxine
D. Liothyronine
E. Phenoxybenzamine
Case 3
Which of the following additional therapies is most indicated?
A. Diltiazem
B. Methimazole
C. Levothyroxine—sometimes used in combination with antithyroid
drugs (block-replace regimen) to avoid drug-induced
hypothyroidism.
D. Liothyronine (oral form of T3)
E. Surgical resection
Hyperthyroidism is treated with antithyroid drugs, radioactive iodine,
or thyroidectomy. Methimazole and PTU inhibit thyroid peroxidase
and thus decrease production of T4 & T3. In Graves’ disease, they also
reduce thyroid antibody levels. Thyroid function tests & clinical
manifestations are reviewed every 3-4 weeks with dose titrated based
on unbound T4. Euthyroidism usually takes 6-8 weeks.
Case 4
40 y/o female with Grave’s disease was recently started on
methimazole. One month later she comes to clinic for a
routine follow up. She notes some low-grade fevers,
arthralgia, and general malaise. Labs show mild
transaminitis and glucose of 150.
All of the following are known side effects of
methimazole except:
A. Agranulocytosis
B. Rash
C. Arthralgias
D. Hepatitis
E. Insulin resistance
Case 4
All of the following are known side effects of methimazole
except:
A. Agranulocytosis
B. Rash
C. Arthralgias
D. Hepatitis
E. Insulin resistance
Methimazole and PTU both inhibit the function of thyroid
peroxidase, reducing oxidation and organification of iodide.
Rash, urticaria, fever & arthralgias are common side effects.
Major side effects are rare but include hepatitis, agranulocytosis
(<1%) & SLE-like syndrome.
Case 5
A patients presents to clinic with complaints of fatigue
& hair loss. He has gained 6.4kg since his last clinic
visit 6 months ago but notes markedly decreased
appetite. On ROS, he reports not sleeping well & feels
cold all the time. He is still able to enjoy his hobbies
and does not believe that he is depressed. Exam
reveals diffuse alopecia and slowed deep tendon reflex
relaxation.
Case 5
Which of the following statements regarding the
most likely diagnosis is correct?
A. A normal TSH excludes secondary, but not primary
hypothyroidism.
B. T3 measurement is not indicated to make the
diagnosis.
C. The T3/T4 ratio is important for determining response
to therapy.
D. Thyroid peroxidase antibodies distinguish between
primary and secondary hypothyroidism.
E. Unbound T4 is a better screening test than TSH for
subclinical hypothyroidism.
Case 5
Which of the following statements regarding the most likely diagnosis is correct?
A.
A normal TSH excludes secondary, but not primary hypothyroidism.
B.
T3 measurement is not indicated to make the diagnosis.
C.
The T3/T4 ratio is important for determining response to therapy.
D.
Thyroid peroxidase antibodies distinguish between primary and secondary hypothyroidism.
E.
Unbound T4 is a better screening test than TSH for subclinical hypothyroidism.
While hypothyroidism may be strongly suspected from history & physical
exam, it is definitively diagnosed with labs. TSH should be the first test
sent. A normal TSH excludes primary, but not secondary,
hypothyroidism. T3 levels are normal in ~25% of patients with
clinical hypothyroidism and not indicated for diagnosis. T3/T4
ratio is not helpful for diagnosis or prognosis. If TSH is low or normal &
pituitary disease is suspected, a free T4 should be sent. If T4 is low, DDx
includes anterior pituitary dysfxn, sick euthyroid syn, & drug effects. In
subclinical hypothyroidism, TSH is the test of choice as TSH is elevated
and T4 in normal. Thyroid peroxidase antibodies are present in >90% of
patients with autoimmune hypothyroidism.
Case 6
A 75 y/o woman is diagnosed with hypothyroidism. She has
long-standing CAD and is wondering about the potential
consequences for her cardiovascular system.
Which of the following statements is true regarding the
interaction of hypothyroidism and the CV system?
A. Myocardial contractility is increased with hypothyroidism.
B. A reduced stroke volume is found with hypothyroidism.
C. Pericardial effusions are rare manifestations of
hypothyroidism.
D. Reduced peripheral resistance is found in hypothyroidism
and may be accompanied by hypotension.
E. Blood flow is diverted toward the skin in hypothyroidism.
Case 6
Which of the following statements is true regarding the
interaction of hypothyroidism and the CV system?
A. Myocardial contractility is increased with hypothyroidism.
B. A reduced stroke volume is found with hypothyroidism.
C. Pericardial effusions are rare manifestations of hypothyroidism.
D. Reduced peripheral resistance is found in hypothyroidism and
may be accompanied by hypotension.
E. Blood flow is diverted toward the skin in hypothyroidism.
Hypothyroidism is associated with bradycardia & reduced
myocardial contractility, thereby reducing stroke volume.
Increase peripheral resistance may be accompanied by diastolic
hypertension. Pericardial effusions are found in up to 30% of
patients. Blood flow is directed away from the skin & thus
produce cool extremities.
Case 7
38 y/o woman presents to clinic complaining of fatigue &
irritability that have been worsening over the past several
months. She has a history of mild intermittent asthma and
hypertriglyceridemia. Exam reveals HR 105, BP 136/72,
bilateral proptosis and warm, moist skin. Screening tests
are sent and reveal a TSH level that is undetectable and a
normal free T4.
What should be the next step in diagnosis?
A. Radionuclide scan of the thyroid
B. Thyroid-stimulating antibody screen
C. Thyroid peroxidase antibody screen
D. Total T4
E. Unbound T3
Case 7
What should be the next step in diagnosis?
A.
Radionuclide scan of the thyroid
B.
Thyroid-stimulating antibody screen
C.
Thyroid peroxidase antibody screen
D.
Total T4
E.
Unbound T3
In patients with thyrotoxicosis due to Graves’ disease, the TSH is
low and total & unbound thyroid hormone levels are increased. In
2-5% of patients, only the T3 levels will be increased. In this
patient with a high pre-test probability of Graves’ disease,
a suppressed TSH & normal T4 supports Graves’;
however, T3 should be tested to definitively make the
diagnosis. Measuring thyroid antibodies will help confirm the
diagnosis of Graves’ but the diagnosis can be made without them.
Radionuclide scan is used to evaluate for toxic multinodular goiter
and toxic adenoma.
Case 8
Which of the following is most consistent with a
diagnosis of subacute thyroiditis?
A. 38 y/o female with 2-wk history of painful thyroid, elevated
T4 & T3, low TSH, and an elevated radioactive iodine
uptake scan.
B. 42 y/o male with history of painful thyroid 4 months ago,
fatigue, malaise, low free T4 & T3, and elevated TSH.
C. 31 y/o female with a painless enlarged thyroid, low TSH,
elevated T4 & free T4, and an elevated radioactive iodine
uptake scan.
D. 50 y/o male with a painful thyroid, slightly elevated T4,
normal TSH, and an ultrasound showing a mass.
E. 46 y/o female with 3 weeks of fatigue, low T4 & T3, and
low TSH.
Case 8
Which of the following is most consistent with a diagnosis of subacute thyroiditis?
A.
38 y/o female with 2-wk history of painful thyroid, elevated T4 & T3, low TSH, and an elevated
radioactive iodine uptake scan.
B.
42 y/o male with history of painful thyroid 4 months ago, fatigue, malaise, low free
T4 & T3, and elevated TSH.
C.
31 y/o female with a painless enlarged thyroid, low TSH, elevated T4 & free T4, and an
elevated radioactive iodine uptake scan.
D.
50 y/o male with a painful thyroid, slightly elevated T4, normal TSH, and an ultrasound
showing a mass.
E.
46 y/o female with 3 weeks of fatigue, low T4 & T3, and low TSH.
Recall the 3 stages of subacute thyroiditis:
1) Thyrotoxicosis—Low TSH, high T4 & T3, radioiodine uptake is low/undetectable.
2) Hypothyroidism—Elevated TSH, low free T4, radioiodine uptake returns to normal.
3) Recovery (4-6 months later)
Patient B is in the hypothyroid stage of subacute thyroiditis.
Patient A is consistent with the thyrotoxic phase except the radioiodine uptake
scan should be decreased, not elevated.
Patient C is more consistent with Graves’ disease.
Patient D is consistent with neoplasm.
Patient E is consistent with central hypothyroidism.
Case 9
A healthy 53 y/o man comes to your office for an annual
physical exam. He has no complaints and has no
significant medical history. He is taking an OTC
multivitamin and no other medications. On exam he is
noted to have a nontender thyroid nodule. His TSH is
found to be low.
What is the next step in his evaluation?
A. Close follow-up and measure TSH in 6 months.
B. Fine-needle aspiration
C. Low-dose thyroid replacement
D. PET followed by surgery
E. Radionuclide thyroid scan
Case 9
What is the next step in his evaluation?
A.
Close follow-up and measure TSH in 6 months.
B.
Fine-needle aspiration
C.
Low-dose thyroid replacement
D. PET followed by surgery
E. Radionuclide thyroid scan
Thyroid nodules are found in 5% of patients and are more common
with age, in women, and in iodine-deficient areas. TSH should be the
first test after detection of a thyroid nodule. In the case of normal
TSH, FNA or US-guided biopsy should be pursued. If the TSH is
low, a radionuclide scan should be performed to determine
if the nodule is the source of thyroid hyperfunction. “Hot”
nodules can be treated medically, resected or ablated with radioactive
iodine. “Cold” nodules should undergo FNA. 4% of nodules will be
malignant, 10% suspicious for malignancy & 86% are indeterminate or
benign.
Case 10
38 y/o mother of three presents to her PCP with complaints of
fatigue and low energy for 3 months. She was previously
healthy and was taking no medications. She does report a 5kg
weight gain and severe constipation, for which she is now taking
laxatives. A TSH is elevated at 25 mU/L. Free T4 is low. She is
wondering why she has hypothyroidism.
Which of the following tests is most likely to diagnose
the etiology?
A. Antithyroglobulin antibiody
B. Antithyroid peroxidase antibody
C. Radioiodine uptake scan
D. Serum thyroglobulin level
E. Thyroid ultrasound
Case 10
Which of the following tests is most likely to diagnose the etiology?
A.
Antithyroglobulin antibiody
B.
Antithyroid peroxidase antibody (TPO)
C.
Radioiodine uptake scan
D.
Serum thyroglobulin level
E.
Thyroid ultrasound
The most common cause of hypothyroidism in the US is autoimmune
thyroiditis, as it is a iodine-replete area. Although earlier in the disease, a
radiooidine uptake scan may have shown diffusely increased uptake from
lymphocytic infiltration, at this point in the disease when the infiltrate is
“burned out” there is likely to be little found on the scan. Likewise, a thyroid
ultrasound would only be useful for presumed multinodular goiter. TPO Abs
are commonly found in autoimmune thyroditis, while antithyroglobulin Abs
are less commonly found. Antithyroglobulin Abs are also found in other
thyroid disorders (Graves’ disease, thyrotoxicosis) and systemic autoimmune
diseases (SLE). Thyroglobulin is released from the thyroid in all types of
thyrotoxicosis with the exception of thyroid disease. This patient, however, is
hypothyroid.
Case 11
A 54 y/o woman with long-standing hypothyroidism is seen by
her PCP for a routine evaluation. She reports feeling fatigues
and somewhat constipated. Since her last visit, her other
medical conditions, which include hypercholesterolemia &
systemic HTN, are stable. She was diagnosed with uterine
fibroids and started on iron recently. Her other meds include
levothyroxine, atorvastatin, and HCTZ. Her TSH is found to be
elevated at 15 mU/L.
Which of the following is the most likely reason for her
elevated TSH?
A. Celiac disease
B. Colon cancer
C. Medication noncompliance
D. Poor absorption of levothyroxine due to ferrous sulfate
E. TSH-secreting pituitary adenoma
Case 11
Which of the following is the most likely reason for her elevated TSH?
A.
Celiac disease
B.
Colon cancer
C.
Medication noncompliance
D. Poor absorption of levothyroxine due to ferrous sulfate
E.
TSH-secreting pituitary adenoma
An increase in TSH in a patient with hypothyroidism that was previously
stable in dosing for many years suggests either a failure of taking the
medication, difficulty with absorption from bowel disease, or medication
interaction. Pts with normal body weight taking >200μg of levothyroxine
per day with continued elevated TSH strongly suggests noncompliance.
Other causes of increased thyroxine requirements include malabsorption
(celiac disease, small bowel resection), estrogen therapy, & drugs that
interfere with T4 absorption (ferrous sulfate, cholestyramine)
or clearance (lovastatin, amiodarone, carbamazepine,
phenytoin).
Case 12
87 y/o woman is admitted to the MICU with depressed
level of consciousness, hypothermia, sinus
bradycardia, hypotension and hypoglycemia. She was
previously healthy with the exception of
hypothyroidism and systemic HTN. Her family mends
that she was not taking any of her medications due to
financial difficulties. There is no evidence of infection
on exam, urine microscopy, or CXR. Her labs are
notable for mild hyponatremia and glucose of 48. TSH
is >100 mU/L.
Case 12
All of the following statements regarding this
condition are true EXCEPT:
A. External warming is a critical feature of therapy in
patients with a temperature above 34º C.
B. Hypotonic IV solutions should be avoided.
C. IV levothyroxine should be administered with IV
glucocorticoids.
D. Sedation should be avoided if possible.
E. This condition occurs almost exclusively in the elderly
and often is precipitated by an unrelated medical
illness.
Case 12
All of the following statements regarding this condition are true EXCEPT:
A. External warming is a critical feature of therapy in patients
with a temperature above 34º C.
B.
Hypotonic IV solutions should be avoided.
C.
IV levothyroxine should be administered with IV glucocorticoids.
D. Sedation should be avoided if possible.
E.
This condition occurs almost exclusively in the elderly and often is
precipitated by an unrelated medical illness.
The patient has myxedema coma. This condition of profound
hypothyroidism most commonly occurs in the elderly, often with a
precipitating condition (e.g. MI, infection). Management includes IV
levothyroxine and glucocorticoids due to impaired adrenal reserve in severe
hypothyroidism. Care must be taken with rewarming as it may precipitate
cardiovascular collapse. Therefore, external warming is indicated only if
temperature is below 30ºC. Hypertonic saline & glucose may be used if
hyponatremia or hypoglycemia is severe; however hypotonic solutions should
be avoided as this may worsen fluid retention.
Case 13
29 y/o woman is evaluated for anxiety, palpitations,
and diarrhea and is found to have Graves’ disease.
Before she begins therapy for her thyroid condition,
she has an episode of acute chest pain and presents to
the ED. Although a CT angiogram is ordered, the
radiologist calls to notify the treating physician that
this is potentially dangerous.
Case 13
Which of the following best explains the radiologist’s
recommendation?
A. Pulmonary embolism is exceedingly rare in Graves’ disease.
B. Radiation exposure in patients with hyperthyroidism is
associated with increased risk of subsequent malignancy.
C. Iodinated contrast exposure in patients with Graves’ disease
may exacerbate hyperthyroidism.
D. Tachycardia with Graves’ disease limits the image quality of
CT angiography and will not allow accurate assessment of
pulmonary embolism.
E. The radiologist was mistaken; CT angiography is safe in
Graves’ disease.
Case 13
Which of the following best explains the radiologist’s recommendation?
A.
Pulmonary embolism is exceedingly rare in Graves’ disease.
B.
Radiation exposure in patients with hyperthyroidism is associated with increased
risk of subsequent malignancy.
C.
Iodinated contrast exposure in patients with Graves’ disease may
exacerbate hyperthyroidism.
D.
Tachycardia with Graves’ disease limits the image quality of CT angiography and
will not allow accurate assessment of pulmonary embolism.
E.
The radiologist was mistaken; CT angiography is safe in Graves’ disease.
Pts with Graves’ disease produce thyroid-stimulating immunoglobulins. They
subsequently produce higher levels of T4 compared with the normal
population. As a result, many patients with Graves’ disease are mildly iodine
deficient, and T4 production is somewhat limited by the availability of iodine.
Exposure to iodinated contrast thus reverse iodine deficiency and may
precipitate worsening hyperthyroidism. Additionally, the reversal of mild
iodine deficiency may make I-125 therapy for Graves’ disease less successful
because thyroid iodine uptake is lessened in the iodine-replete state.
Case 14
Which of the following statements best
describes Graves’ ophthalmopathy?
A. Although a cosmetic problem, Graves’
ophthalmopathy is rarely associated with major
ocular complications.
B. Diplopia may occur from periorbital muscle
swelling.
C. It is never found without concomitant
hyperthyroidism.
D. The most serious complication is corneal abrasion.
E. Unilateral disease is not found.
Case 14
Which of the following statements best describes Graves’ ophthalmopathy?
A.
Although a cosmetic problem, Graves’ ophthalmopathy is rarely
associated with major ocular complications.
B. Diplopia may occur from periorbital muscle swelling.
C.
It is never found without concomitant hyperthyroidism.
D. The most serious complication is corneal abrasion.
E.
Unilateral disease is not found.
Although lid retraction can occur in any type of hyperthyroidism, Graves’
disease is associated with specific eye signs that are thought to be due to
the interaction of autoantibodies within the periorbital muscles. The
onset of Graves’ ophthalmopathy may occur before or after
hyperthyroidism, and rarely may not be associated with hyperthyroidism
at all. Proptosis occurs in 1/3 of patients and may result in corneal
abrasion if there is failure of closure of the eyelids, esp during sleep.
However, the most serious manifestation is compression of the optic
nerve at the apex of the orbit, which can lead to papilledema and
permanent vision loss if left untreated.
Case 15
23 y/o woman is evaluated for a 2 week history of
nervousness, palpitations, nausea, vomiting and weight
loss. She is 3 weeks pregnant and says she was previously
in excellent health. The patient takes a daily prenatal
multivitamin but no other prescription medication, iodine
supplement or other OTC meds.
On exam: BP 130/79, HR 110 and regular. Cardiac, lung,
and eye exam are normal. The thyroid gland shows a
significantly enlarged gland with a soft bruit but no
nodules. No neck tenderness. Abdominal exam reveals a
2cm patch of vitiligo. A fine bilateral hand tremor and
warm, moist skin are noted. No evidence of pretibial
myxedema.
Case 15
Labs:
CBC & CMP: normal
TSH: < 0.01, Free T4: 4.0 (high), Free T3: 6 (high)
Human chorionic gonadotropin: positive
Thyroid peroxidase Ab: 40 units/L (normal is <20)
Thyroid stimulating Ab: 140% (normal is <130%)
Which of the following is the most appropriate initial
treatment?
A. Methimazole
B. Propylthiouracil
C. Thyroidectomy
D. Reassurance
Case 15
Which of the following is the most appropriate initial treatment?
A. Methimazole
B. Propylthiouracil
C. Thyroidectomy
D. Reassurance
In pregnant women, untreated hyperthyroidism is associated
with an increased risk of miscarriage, fetal growth retardation,
premature delivery, and preeclampsia. This patient has
autoimmune Graves hyperthyroidism and should receive
propylthiouracil while in the 1st trimester of pregnancy. She can
switch to methimazole in the 2nd & 3rd trimesters, at which time
there is decreased risk of fetal abnormalities (e.g. aplasia cutis,
choanal atresia) after fetal organogenesis.
References
 Agabegi SS, Agabegi ED. Step-Up to Medicine, 3rd ed. 2013.
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Lippincott Williams & Wilkins. Philadelphia, PA.
DeGroot, LJ. Diagnosis and Treatment of Grave’s Disease. Feb
2012. http://www.thyroidmanager.org/chapter/diagnosis-andtreatment-of-graves-disease/
Sabatine MS. Pocket medicine, 4th ed. 2011. Lippincott Williams &
Wilkins. Philadelphia, PA.
Trevor AJ, Katzung BG, Kruidering-Hall M, et al. Katzung &
Trever’s Pharmacology: Examination & Board Review, 10th ed.
2013. McGraw-Hill. New York, NY.
Weiner C, Fauci AS, Braunwald E, et al. Harrison’s Principles of
Internal Medicine: Self-Assessment & Board Review, 17th ed & 18th
ed. 2008, 2012. Lippincott Williams & Wilkins. Philadelphia, PA.
Special thanks to Dr. Sood for the inspiration!