2.1.3 AI Summary: Hyperthyroidism

What is hyperthyroidism defined as?

Overexposure of tissues to thyroid hormones

What lab pattern is seen in hyperthyroidism?

Low TSH with high T4

What diagnostic test helps determine cause of hyperthyroidism?

Radioactive iodine uptake

What does high radioactive iodine uptake indicate?

Endogenous hormone overproduction

What does low radioactive iodine uptake indicate?

Thyroiditis or exogenous hormone

What is the most common cause of hyperthyroidism?

Graves disease

What physical finding is common in Graves disease?

Goiter

What eye manifestation is associated with Graves disease?

Exophthalmos/buldging eyes

What are common symptoms of hyperthyroidism?

Weight loss, heat intolerance, tachycardia, fine hair

What complications are associated with hyperthyroidism?

Atrial fibrillation, congestive HF, osteoporosis, anorexia

What are the goals of hyperthyroidism treatment?

Reduce hormone levels and control symptoms

Disadvantages of anti-thyroid drugs?

low cure rate, adverse effects, compliance, continued monitoring

What are the three main treatment options for hyperthyroidism?

Antithyroid drugs, radioactive iodine, surgery

What are the two main antithyroid drugs?

Methimazole and propylthiouracil

What is the mechanism of antithyroid drugs?

Inhibit thyroid hormone synthesis

Which antithyroid drug is preferred in most patients?

Methimazole

Which antithyroid drug is preferred in first trimester pregnancy?

Propylthiouracil

How long do antithyroid drugs take to work?

Three to four weeks

What serious adverse effect can occur with antithyroid drugs?

Agranulocytosis, aplastic anemia, lupus-like illness, polymyositis

What symptom suggests agranulocytosis?

Fever or sore throat

What severe liver toxicity risk is associated with PTU?

Hepatotoxicity

What is a common minor side effect of antithyroid drugs?

Rash or GI upset

How often should thyroid labs be monitored after starting therapy?

Every four to six weeks

1st line treatment in children/adolescents/pregnancy?

antithyroid meds

Why is TSH not reliable early in treatment?

It lags behind hormone changes

What medication class is used for symptom control (ie tremor,anxiety,palpitations) in hyperthyroidism?

Beta blockers

Inhibits t4 conversion to t3

Which beta blockers reduce T4 to T3 conversion?

Propranolol and nadolol

What is the onset for beta-blockers?

rapid

Adverse effects of beta blockers?

hypotention,bradycardia,fatigue

What is the role of iodides in treatment?

Block hormone release and conversion

When are iodides typically used?

Before surgery or in thyroid storm

What is the most cost-effective definitive treatment?

Radioactive iodine

What is a major outcome of radioactive iodine therapy?

Permanent hypothyroidism

What is a contraindication to radioactive iodine therapy?

Pregnancy, breastfeeding, thyroid cancer, pregnancy w/i 6 months

Treatment of choice for persistant hyperthyroidism?

Radioactive iodine

What treatment is used for large goiters or suspected malignancy?

Surgery

What is a disadvantage of surgery?

Invasive with complications

What condition requires emergency treatment in hyperthyroidism?

Thyroid storm

What are key symptoms of thyroid storm?

Fever, tachycardia, altered mental status

What medication is used in high doses during thyroid storm?

Propylthiouracil (high dose), iodidea, beta blockers, corticosteroids

What drug interaction occurs with warfarin and thyroid disease?

Altered clotting factor metabolism; decreases warfarin effect

May have effect INCREASED by propylthiouracil

What lab should be monitored with antithyroid drugs?

Complete blood count

What is the treatment duration for antithyroid drugs?

Up to 24 months

What percentage of patients achieve remission with antithyroid drugs?

40-50%

What is a key counseling point for antithyroid drugs?

Report signs of infection immediately