Thyroid Disorders and Treatment

What are some risk factors of thyroid disease?

Personal history, strong family history, autoimmune disease, past history of neck irritation, lithium and amiodarone, women >50, elderly, women 6wks-6mo post-partum

What can be imagined as turning the dial down on a person?

Hypothyroidism

What can be imagined as turning the dial up on a person?

Hyperthyroidism

What are normal levels of TSH?

0.3-3mIU/ml

What are normal levels of T4?

0.9-2.4ng/dL

What are normal levels of T3?

60-171ng/dL

What do the levels of TSH, T4, and T3 look like in hypothyroidism?

Increased, decreased, decreased

What do the levels of TSH, T4, and T3 look like in hyperthyroidism?

Decrased, increased, increased

Damage to the thyroid is generally ___

Permanent

What are hallmark indicators of primary hypothyroidism?

Anti-TPO antibodies

Where is iodine absorbed?

GI tract then taken up by thyroid gland

What is the transport of iodine into follicular cells dependent upon?

Na+/I- cotransport system

What is it called when iodine levels, specifically acutely high, temporary intake of exogenous iodine can result in a decrease of thyroid hormone production?

Wolff-Chaikoff effect

What are some treatments for hypothyroidism?

Synthroid, Unithroid, Levoxyl

What is the usual dose of levothyroxine for hypothyroidism treatment?

1.6mcg/kg/d target; 50mcg/d starting point with titration to 100mcg after 4wks

What is the low start dose of levothyroxine for hypothyroidism treatment in elderly and pre-existing cardiac dx?

25mcg/d; titrate by 12.5-25mcg increments q4-6wk

What is the dose of levothyroxine for hypothyroidism treatment in pregnacy?

2-2.4mcg/kg/d

What should be monitored in hypothyroidism treatment?

TSH, FT4 q6w until euthyroid

What is a synthetic T4?

Levothyroxine

What is a synthetic T3?

Liothyronine (Cytomel)

What is a combination of T3 and T4?

Liotrix (Thyrolar)

What are some AEs from excessive doses of hypothyroidism treatment?

CHF, angina, MI, osteoporosis

How do insulin and digoxin effect hypothyroidism drugs?

Lower dose required

How does warfarin effect hypothyroidism drugs?

Dose adjustment and monitoring required

How does respiratory depressants effect hypothyroidism drugs?

Avoid use

What are the treatment options for hyperthyroidism?

Surgery, RAI, antithyroid drugs

What are used to prepare for thyroidectomy?

Thioamide to attain euthyroid (6-8wks), potassium iodine 500mg/d (10-14d before procedure), propranolol preop and 7-10d post-op to control pulse

What is the dosing of Propylthiouracil (PTU) for hyperthyroidism?

100mg q6-8h (maintenance 50-300mg qd)

What are some AEs of PTU?

Hepatoxicity, rash

What is the dosing of Methimazole (Tapazole) for hyperthyroidism?

30-40mg qd (maintanence 5-30mg qd)

What is the some AEs of Methimazole (Tapazole) for hyperthyroidism?

Blood dyscrasias, neuropathies, SLE, myopathies, rash

What needs to be monitored for hyperthyroidism drug therapy?

FT4, TSH, CBC, clinical symptoms

What is the dosing of SKKI for adjunct therapy of hyperthyroidism?

38mg/drop