QUESTIONS & DETAILED SOLUTIONS
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Thyroid
o Diagnosis & Evaluation
What labs are used to diagnose?
-TSH - used primarily for screening and diagnosing hypothyroid and for monitoring replacement
therapy in hypothyroid patients
-T4 - Used to monitor thyroid hormone replacement therapy and to screen for thyroid
dysfunction
-T3 - Useful in the diagnosis of hyperthyroidism; can also be used to monitor hormone
replacement therapy
-TSH low
-T4 normal
-T3 is high = hyperthyroidism
Thyroid
o Diagnosis & Evaluation
Timeframe for re-check of labs after starting levothyroxine?
Recheck TSH 6-8 weeks after initiating therapy and after any dosage change; Check TSH at least
once a year after serum TSH is stabilized
Thyroid
o Diagnosis & Evaluation
Signs and symptoms of hypothyroidism?
Hypothyroidism: Depend on severity.
,o Mild: subtle and may go unrecognized
o Moderate to severe:
-Face is pale, puffy, and expressionless.
-Skin cold and dry.
-Hair is brittle and hair loss occurs.
-Slowed Heart rate.
-Patient may complain of lethargy, fatigue, and
-Temperature is lowered & intolerant to cold.
-Thyroid Enlargement may occur if reduced levels of T3
and T4
Mentation may be impaired.
Thyroid
o Diagnosis & Evaluation
Signs and symptoms of hyperthyroidism?
o Elevated Heart rate and strong, and dysrhythmias and angina may develop
o The CNS is stimulated, resulting is nervousness, insomnia, rapid thought flow, and rapid
speech, hyperreflexia, tremors
o Skeletal muscles may weaken and atrophy
o Metabolic rate is raised, resulting in health and skin that is warm and moist
o Feeling Hot + Heat intolerance
o Appetit is increased but fails to match metabolic rate resulting in weight loss
o All of these signs are referred to as thyrotoxicosis
o Also usually present with exophthalmos - bulging of the eyes
Thyroid
o Treatment
Treatment of thyroid storm?
,Characterized by profound hyperthermia (105 degrees F or higher), severe tachycardia,
restlessness, agitation, and tremor.
Unconsciousness, coma, hypotension, and heart failure may ensure.
These symptoms are produced by excessive levels of thyroid hormone
Thyroid crisis can be life threatening and requires immediate treatment.
o High doses of potassium iodide or strong iodine solution are given to suppress thyroid
hormone release.
o Methimazole is given to suppress thyroid hormone synthesis
o A beta blocker is given to reduce heart rate
o Additional measures include sedation, cooling, and giving
glucocorticoids and IVF
Thyroid
o Treatment
Result of not treating hypothyroidism during pregnancy?
Can result in permanent neuropsychological deficits in the child - decrease child's IQ
The effect of hypothyroidism is limited largely to the first trimester, a time during which the
fetus is unable to produce thyroid hormone of its own
Some authorities currently recommend routine screening for hypothyroidism as soon as
pregnancy is confirmed
Women already taking thyroid hormone replacement will need to increase dose by 50% max
between weeks 4-8 of gestation and the levels will level out by week 16
Thyroid
o Treatment
Medication to treat symptoms of hyperthyroidism (notice this is treating symptoms and not the
hyperthyroidism itself)
Methimazole - first line drug of choice (not given to women who are pregnant or breastfeeding)
o Methimazole blocks synthesis of thyroid hormone.
1) Prevents the oxidation of iodine, therefore inhibiting incorporation of iodine into tyrosine.
2) prevents iodinated tyrosine from coupling
Propylthiouracil - preferred treatment for thyroid storm
Beta blockers - help with tachycardia experienced with hyperthyroidism
, Thyroid
o Treatment
Drug/Food/Supplement interactions with levothyroxine
Absorption of levothyroxine is reduced by food - it should be taken on an empty stomach in the
morning, at least 30-60 minutes before breakfast
Drugs that reduce absorption include: H2 receptor blockers, PPIs, Carafate, Questran, Colestid,
Maalox/Mylanta, Tums, iron, Mag salts, Xenical
Drugs that accelerate levothyroxine: Phenytoin, Carbamazepine, rifampin, Sertraline, and
phenobarbital
Patients taking the following drugs may need to increase their dose of levothyroxine: Warfarin
and catecholamines
Levothyroxine can also increase requirements for insulin and digoxin
Diabetes
o How to confirm a diagnosis prior to beginning treatment
Fasting plasma glucose >/= 125mg/dl OR
Random plasma glucose >/= 200mg/dl
plus symptoms of diabetes (polyuria, polydipsia, unexplained weight loss) OR
Oral glucose tolerance test (OGTT): 2-hour plasma glucose >/= 200mg/dl OR
HgbA1C pf 6.5% or greater - (a test that provides an estimate of glycemic control over the
previous 2-3 months) is now considered a standard test as well
Diabetes
o A1C
General goals
To keep A1C below 7%
o <8% is less stringent for those with hx. Of severe hypoglycemia, limited life expectancy, pr
advanced microvascular or macrovascular complications
Diabetes