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Source: Jonklaas J, Kane MP. Thyroid disorders. In: DiPiro JT, Talbert RL, Yee GC, Matzke GR, Wells BG, Posey LM, eds. Pharmacotherapy: A Pathophysiologic Approach. 10th ed. New York, NY: McGraw-Hill; 2017. http://accesspharmacy.mhmedical.com/content.aspx?bookid=1861§ionid=146066204. Accessed April 14, 2017.
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CONDITION/DISORDER SYNONYMS
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Thyrotoxicosis.
Overactive thyroid.
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Thyrotoxicosis results when tissues exposed to excessive levels of thyroxine (T4), triiodothyronine (T3), or both.
TSH-secreting pituitary tumors release active hormone unresponsive to normal feedback control.
In Graves’ disease, hyperthyroidism results from action of thyroid-stimulating antibodies (TSAb).
Autonomous thyroid nodule (toxic adenoma) is thyroid mass whose function is independent of pituitary control.
In multinodular goiters, follicles with autonomous function generate more thyroid hormone than required.
Painful subacute thyroiditis often develops after viral illness.
Painless thyroiditis may have underlying autoimmune cause.
Amiodarone may induce thyrotoxicosis and may also cause destructive thyroiditis with loss of thyroglobulin and thyroid hormones.
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CLINICAL PRESENTATION
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Symptoms:
Nervousness.
Anxiety.
Palpitations.
Emotional lability.
Easy fatigability.
Heat intolerance.
Weight loss with increased appetite.
Increased frequency of bowel movements.
Proximal muscle weakness.
Scanty or irregular menses in women.
Signs:
Thyroid enlargement.
Exophthalmos.
Pretibial myxedema.
Warm, smooth, moist skin and unusually fine hair.
Onycholysis.
Lid lag.
Resting tachycardia, widened pulse pressure, and systolic ejection murmur.
Gynecomastia in men.
Fine tremor of protruded tongue and outstretched hands.
Hyperactive deep tendon reflexes.
Thyroid storm:
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TSH, total T4, free T4, T3 resin uptake, free thyroxine index, 24-hour radioactive iodine uptake (RAIU).
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DIFFERENTIAL DIAGNOSIS
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Eliminate excess thyroid hormone.
Minimize symptoms and long-term consequences.
Provide individualized therapy based ...