377 Hyperthyroidism Flashcards
Preferred drug for thyroid storm
PTU
Instance PTU is given over methimazole
Thyroid storm
Allergy to PTU
First trimester of pregnancy
Adverse effect of PTU which make it less preferred than methimazole
Hepatotoxicity
Most common sign of hyperthyroidism
Tachycardia
Most common cause of Thyrotoxicosis
Graves disease
Thyrotoxicosis vs hyperthyroidism
Thyrotoxicosis: state of thyroid hormone excess
Hyperthyroidism: excessive thyroid hormone
Side effects of PTU if taken during pregnancy
Cutis aplasia
Choanal atresia
Patient usually presents with painful and enlarged thyroid, sometimes accompanied by fever
Subacute/ De Quervains thyroiditis
Dreaded side effect of methimazole
Agranulocytosis
Added benefit of using propanolol in hyperthyroidism
Prevents peripheral conversion of T3 to T4
Why exopthalmus in Graves disease
Deposition of fat around the orbits pushes the eyes
what’s the most serious manifestation of Graves ophthalmopathy
compression of the optic nerve
defined as a state of thyroid hormone excess
thyrotoxicosis
major etiologies of thyrotoxicosis
hyperthyroidism caused by Grave’s disease, toxic multinodular goiter, and toxic adenomas
True or false. Grave’s disease accounts for 60-80% of thyrotoxicosis
True.
Accounts for 60-80% of thyrotoxicosis
Graves’ disease
minor risk factor for Graves disease and a major risk factor for ophthalmopathy
Smoking
True or false. Graves disease may occur during the immune reconstituution phase after highly active antiretroviral therapy (HAART) or alemtuzumab treatment
True.
Kinase inhibitor associated with precipitating Graves disease
alemtuzumab
True or false. Cytokine play a major role in thyroid assocaited ophthalmopathy
True.
commonly seen in elderly patients where features of thryotoxicosis are subtle or masked with patients present mainly with fatigue and weight loss
apathetic thyrotoxicosis
signs specific for Graves disease
ophthalmopathy and dermopathy
True or false. Thyrotoxicosis is sometimes associated with a form of hypokalemic periodic paralysis
True.
True or false. Atrial fibrillation among hyperthyroidism patient is seen in those aging more than 50 yrs
True.
Which is more common in patients with hyperthyroidism
hypercalciuria is more common
where is the bruit best heard in patients with enlarged thyroid in Graves disease
inferolateral margins
what causes lid retraction in patients with hyperthyroidism
sympathetic overactivity
earliest manifestations of ophthalmopathy
sensation of grittiness, eye discomfort, and excess tearing
how is ptosis best detected
visualization of the sclera between the lower border of the iris and the lower eyelid with the eyes in primary position
NO SPECS scoring to evaluate ophthalmopathy
0 No signs 1 Only lid retraction 2 Soft tissue involvement 3 Proptosis more than 22 mm 4 EOM involved 5 Corneal involvement 6 Sight loss
Measurement of proptosis in thyroid ophthalmopathy
more than 22 mm
thyroid dermopathy occurs in many percent of patients with Graves disease
5%
commonly affected area for thyroid dermopathy
over the anterior and lateral aspect of the lower leg
name of the thyroid dermopathy that occurs in the legs
pretibial myxedema
refers to the noninflamed indurated plaque with a deep pink or purple color and an orange skin appearance
pretibial myxedema
refers to form of clubbing that occurs in patients with hypethyroidism
thyroid acropachy
incidence of thyroid acropachy
1.00%
Evaluation of thyrotoxicosis. TSH low FT4 high. Diagnosis?
Primary thyrotoxicosis
Evaluation of thyrotoxicosis. TSH low FT4 high. No features of Graves? Considerations
multinodular or toxic adenoma.
Evaluation of thyrotoxicosis. TSH low FT4 high. No features of Graves. Not multinodular goiter. Not toxic adenoma. What to do next?
radionuclide uptake
Evaluation of thyrotoxicosis. TSH low FT4 high. No features of Graves. Not multinodular goiter. Not toxic adenoma. Low radioiodine uptake
Destructive thyroiditiis, iodine excess, or excess thyroid hormone
Evaluation of thyrotoxicosis. TSH low FT4 high. No features of Graves. Not multinodular goiter. Not toxic adenoma. With radioiodine uptake
Rule out other causes including stimulation of choroinic gonadotropin
Evaluation of thyrotoxicosis. TSH low FT4 normal. What to do next?
Get FT3
Evaluation of thyrotoxicosis. TSH low FT4 normal. FT3 high.
T3 toxicosis
Evaluation of thyrotoxicosis. TSH low FT4 normal. FT3 normal.
subclinical thyperthyroidism
what to do with subclinical hyperthyroidism
Follow up in 6-12 weeks
Follow up in 6-12 weeks
TSH secreting pituitary adenoma or thyroid hormone resistance syndrome
Evaluation of thyrotoxicosis. TSH normal FT4 normal. What to do next?
No further tests
How is Graves disease differentiate from destructive thyroiditis, ectopic thyroid tissue, and factitious thyrotoxicosis, toxic adenoma, or toxic MNG
High uptake of radionuclide in Graves disease
Differentials of Graves who presents with thyrotoxicosis but without ophthalmopathy or dermopathy
destructive thyroiditis, ectopic thyroid tissue, and factitious thyrotoxicosis, toxic adenoma, or toxic MNG
what is the mortality of hyperthyroidism without treatment
10-30%
When does thyroid dermopathy develop
1-2 years after the development of Graves hyperthyroidism
True or false. Thyroid dermopathy can resolve spontaneous once Graves disease is treated
True.
main antithyroid drugs
thiomides, PTU, methimazole
What is the action of antithyroid drugs
inhibit the function of TPO, reducing oxidation and organification of iodide
Mechanism of action of PTU
inhibits the deiodination of T4 to T3
half life of PTU
90 mins
half life of methimazole
6 hrs
what is the adverse effect of PTU limiting is use in the first trimester of pregnancy
hepatotoxicity
what is the initial dose of methimazole
10-20 mg BID then once a day dosing once euthyroidism is achieved
what is the dose of PTU
100-200 mg q6-8 hrs
when are thyroid function tests reviewed
4-6 weeks after starting treatment
True or false. TSH levels often remain suppressed for several months and therefore do not provide a sensitive index of treatment response
True.
daily maintenance dose of methimazole
2.5 -10 mg OD
daily maintenance dose of PTU
50-100 mg OD
what is the block and replace regimen
initial dose of antithyroid is held constant and the dose of levothyroxine is adjusted to maintain FT4 in normal levels
types of patients most likely to relapse
younger patients, males, smokers and patients with a history of allergy, sever hyperthyroidism, or large goiters
when is maximum remission achieved in 30-60% of patients
By 12-18 months
common minor side effects of anti thyroid drugs
rash, fever, urticaria, and arthralgia
what to do if with minor side effects
change to another antithyroid drug
major side effect of methimazole
cholestasis
most important adverse effect of antithyroid drugs
agranulocytosis
alternative to propanolol in hyperthyroidism
atenolol
dose of propanolol
20-40 mg every 6hrs
when should carbimazole to methimazole stopped prior to radioiodine
Stopped 2-3 days before radioiodine administration to achieve optimum iodine uptake
when should carbimazole to methimazole resumed after radioiodine
re started 3-7 dats after radioiodine
true or false. PTU appears to have a prolonged radioprotective effects and should be stopped for a longer period before radioiodine is given
True.
how long should patients after radioiodine avoid contact or remain in isolation
5-7 days to avoid possible transmission of radioisotope
what is the usual radioiodine dose
370 Mbq (10 mCi) and 555 Mbq (mCi)
True or false. Hyperthyroidism can persists for 2-3 months before radioiodine takes full effect
True.
absolute contraindication to radioiodine
pregnancy and breast feeding
can be given to prevent exacerbation of ophthalmopathy
Prednisone 30 mg/day at the time of radioioidine treatment and tapered over 6-8 weeks
given to reduce vascularity of the thyroid gland
potassium iodide 1-2 SSKI orally TID for 10 days
in pregnant women with hyperthyroidism, until when should PTU be given
PTU should be used until 14-16 weeks
why PTU in the first trimester of pregnancy
due to methimazole carbimazole embryopathy such as cutis aplasia, choanal atresia and tracheoesophageal fistula
what is the ratio of PTU to methimazole
15-20 mg PTU to 1 mg methimazole
heralds neonatal thyrotoxicosis
poor intrauterine growth, FHT more than 160 bpm, advanced bone age, fetal goiter and high levels of maternal TSI after 26 weeks gestation
True or false. Postpartum is a time for major risk
True.
presents as a rare life threatening exacerbation of hyperthyroidism accompanied by fever, delirium, seizures
thyrotoxic crisis or thyroid storm
mortality rate of thyroid storm
30%
what is the dose of PTU in thyroid storm
500-1000 mg loading dose and 250 mg every 4 hours
alternative to PTU in thyroid storm
Methimazole 20 mg every 6 hours
what is the role of propanolol in thyroid storn
high doses of propanolol decrease T4 to T3 conversion
how to give hydrocortisone in thyroid storm
Hydrocortisone 300 mg IV bolus then 100 mg IVTT q8hrs
treatment for severe ophthalmpathy
pulse therapy with IV methylprednisolone 500 mg of once weekly for 6 weeks then 250 mg once weekly for 6 weeks
which is preferred in treatment of opthalmopathy: oral or iv steroid?
IV pulse therapy
amiodarone treatment is associated with how many percent of thyrotoxicosis
10%
due to suppurative infection of the thyroid
acute thyroiditis
most common cause of acute thyroiditis in children and young adults
remnant of the piriform sinus
other term for subacute thyroiditis
de Quervains thyroiditis or granulomatous thyroiditis or viral thyroiditis
usual presentation of subacute thyroiditis
painful goiter and fever
three distinct phases of subacute thryoiditis
thyrotoxic phase, hypothyroid phase and recovery phase
thyrotoxic phase, hypothyroid phase and recovery phase
Aspirin 600 mg every 4-6 hours or NSAIDs
in subacute thyroiditis, it no relief with NSAID, what to give next
Prednisone 15-40 mg tapered over 6 weeks
True or false. In subacute thyroiditis, antithyroid drugs have no role during the thyrotoxic phase
True.
can levothyroxine be given to subacute thyroiditis
yes when hypothyroid phase is prolonged. Low dose levothyroxine 50-100 ug to allow TSH mediated recovery
time period of thyrotoxic phase
Weeks 1-6
time period of hypothyroid phase
Weeks 6-12
time period of recovery phase
Weeks 12-18
names of postpartum thyroiditis
silent thyroiditis
silent thyroiditis, silent thyroiditis
thyrotoxicosis for 2-4 weeks followed by hypothyroidism for 4-12 weeks then resolution
True or false. Silent thyroiditis is more common in women with type 1 diabetes mellitus
True
how to differentiate silent thyroiditis form subacute thyroiditis
normal ESR and TPO antibodies
True or false. Silent thyroiditis patient may develop permanent hypothyroidism
True.
What is the treatment of silent thyroiditis
Propanolol 20-40 mg
what drugs can lead to drug induced thyroiditis
INF alpha, IL1, tyrosine kinase inhibitors may develop painless thyroiditis
True or false. Any acute severe illness can cause abnormalities of circulating TSH or thyroid hormone levels in the absence of underlying thyroid disease
True.
What is the major cause of these hormonal changes in the thyroid
IL 6
what is the other name of sick euthyroid sydrome
non thyroidal illness
what is the hormone pattern in sick euthyroid syndrome
decrease in TT3 and FT3, with normal levels of T4 and TSH
True or false. The magnitude of the fall in T3 correlated with the severity of the illness
True.
in acute liver disease, what leads to rise in thyroid hormone
rise in total but not free T3 and T4 due to TBG release
True or false. Renal disease is often accompanied by low T3 concentrations
True.
dose of amiodarone associated with very high iodine intake
Amiodarone 200 mg per day
True or false. Amiodarone’s high iodine levels can persists for more than 6 months as it is stored in adipose tissues
True.
What are the effects of amiodarone on thyroid function
- acute transient suppression of thyroid function, 2. hypothyroidism in patients susceptible to the inhibitory effects of a high iodine load 3. thyrotoxicosis in that can cause either a Jod Basedow effect from the iodine load, in the setting of MNG or incipient Grave’s disease or thyroiditis like condition
what is the typical thyroid function test pattern of amiodarone induced thyroid dysfunction
increased T4, decrased T3, increased rT3 and transient increased in TSH up to 20 mIU/L
Type of Amiodarone induced thyrotoxicosis associated with underlying thyroid abnormality
Type I AIT
Type of AIT which occurs in individuals with no intrinsic thyroid abnormalities and is the result of drug induced lysosomal activation leadint to destructive thyroiditis with histiocyte accumulation
Type II AIT
major side effect of perchlorate treatment
agranulocytosis
what may be given to AIT
potassium perchlorate 200 mg every 6 hrs
Most sensitive test for hyperthyroidism
T4; you cannot distinguish primary thyrotoxicosis without it
True or false. Patient with Grave’s disease are at increased risk for thyroid cancer
True.
how to rule out subacute thryroiditis
painful gland and a prior fever
True or false. Earliest manifestation of Graves or thyrotoxicosis is elevated T3
True.
How to rule out destructive thyroiditis,
Radioiodine uptake
how to rule our secondary hyperhhyroidism due to a TSH secreting pituitary tumor
CT scan or MRI
True or false. Those who enter remission after treatment develop hypothyroidism
True.
when ophthalmopathy worsens? Plateau?
worsen over the initial 3-6 months; plateau for 1-2 months before resolution
True or false. Radioiodine may worsen eye disease esp amokng smokers
True.
indications of PTU
first trimester of pregnancy, treatment of thyroid storm, patient with minor adverse reaction to methimazole
True or false. Carbimazole or methimazole also can be given once a day once on euthyroidism
True.
Baseline liver function tests before starting PTU/methimazole?
Yes as it can cause PTU hepatocellular toxicity and cholestasis in methimazole; 5x ULN SGPT to reconsider PTU/methimazole
True or false. Block and replace regimen is not well validated way of titrating methimazole
True.
when is euthyroidism expected
6-8 weeks after treatment is initiated
when is remission expected
achieved y 12-18 months; higher in patients with Trab levels are no longer detected; TRab is sent to Manila and if not detected, treatment may be stopped; anti TPO may be used instead and treatment discontinued if not detected
when do you say patient is in remission
12 months off antithyroid drugs with no symptoms
limit of methimazole to avoid liver problems
not more than 40 mg per day to avoid side effects
True or false. Baseline CBC is needed; ANC less than 1000; patient should stop methimazole/PTU
True.
When RAI advocated
with co morbidities who cannot undergo surgery, with adverse effects to antithyroid drugs
when is antithyroid stopped and resumed before after RAI
methimazole stopped 3 days prior to RAI; PTU stopped 7 days prior; antithyroid drugs resumed 7 days after RAI
when does radiation thyroiditis occur
1-2 weeks after treatment
if patient is persistently hyperthyroidism after 2-3 months, when do to repeat RAI
Usually 6 months after first dose
risk for hypothyroidism after RAI
at least 10-20% in the first year
True or false. Moderate to severe ophthalmopathy, RAI avoided
True.
What pre medication of patient with mild ophthalmopathy prior to RAI
prednisone
True or false. Ophthalmopathy exaggerates if hyperthyroid patient goes into hypothyroidism
True.
major complications of thyroidectomy
bleeding, laryngeal edema, hypoparathyroidism and damage to recurrent laryngeal nerves
pre medication prior to thyroidectomy
to avoid hungry bone; pre medicate with calcium and vitamin D or calcitriol
Can you give SSKI to toxic adenoma or Toxic MNG goiter
no; counterproductive
for monitoring post treatment in adjusting dose of antithyroid drugs
T4
True or false. Multiple 1.5 to patient’s result of FT4 and TT4 and still within the range then the rise is related to pregnancy
True.
True or false. If methimazole 5-10 mg per day or PTU less than 100-200 mg after evaluation, then medication can be discontinued in a newly pregnat women with Grave’s disease
True.
what beta blocker to be given in pregnant patient with hyperthyroidism
propanolol and metoprolol; not atenolol as it is assocaited with restricted fetal growth
True or false. Gestation thyrotoxicosis in first 16 weeks of AOG does not need treatment
True esp if FT4 is just within high normal
specifics in SSKI
Give 1 hr after loading dose of PTU in thyroid storm; never before
high uptake on RAI. Graves or thyroiditis?
Graves’ disease
what confers subacute thyroiditis
elevated ESR
thyroiditis with normal thyroid test all through out
subacute thyroiditis
postpartum vs subacute v silent thyroiditis
Subacute = painful silent= no
Medications causing elevated FT4
NSAIDs, furosemide, antiepileptics
medications that cause low TSH
dopamine, steroids, somastostatin, bromocriptine
Conditions that increase thyroid hormone by increasing TBG
pregnancy, oral contraceptive, hormone therapy, selective estrogen receptor modulators, inflammatory liver disease. Anything that increases estrogen
Conditions that decrease total thyroid hormones by decreasing TBG levels
androgens, nephrotic syndrome
best way to physically examine the thyroid gland
palpate each lobe with both lands from behind
markers of hashimoto’s thyroiditis
positive anti TPO and anti Tg
Thyroid scan findings. Enlarged gland with homogenously increased uptake
Graves disease
Thyroid scan findings. Focal area of increased uptake with suppressed uptake in the remainder of the gland
Toxic adenoma
Thyroid scan findings. Very low uptake because follicular cell damage and TSH suppression
Subacute, viral and postpartum thyroiditis
Thyroid scan findings. Low uptake
Thyrotoxicosis factitia
Dose titration of anit thyroid drugs is based on
T4 levels
True or false. Beta blockers control adrenergic symptoms after anit thyroid drugs take effect
False. Before anti thyroid drugs take effect
stopped weeks before radioiodine due to its prolonged radioprotective properties
PTU
True or false. Graves ophthalmopathy does not parallel with thyroid disease
True.
How is the critical picture of graves ophthalmopathy
worsens in 3-6 months plateaus in the next 12-18 months with spontaneous improvement
True or false. RAI can worsen graves ophthalmopathy esp among smokers
True.
10-10 rule in graves ophthalmopathy
ophthalmopathy occurs without hyperthyroidism in 10% and unilateral signs in 10%
when is euthyroidism expected once treatment started
6-8 weeks
when to check FT4 and symptoms of hyperthyroidism
4-6 weeks after starting treatment
