Hypo- and Hyperthyroidism Flashcards
What are the symptoms of Hyperthyroidism?
- Heat Intolerance
- Weight loss
- Tremor
Diarrhea, frequent stools Amenorrhea, light menses Weakness, fatigue Nervousness, irritability, insomnia Weight gain due to ↑ appetite Palpitations Pedal edema
What are the physical findings than Hyperthyroidism?
- Thinning of hair (fine)
- Proptosis, lid lag
- Lid retraction
- Goiter
Stare Periorbital edema Flushed, moist skin Pretibial edema Palmar erythema Brisk DTRs Conjunctivitis Chemosis Loss of extraocular movements Diffusely enlarged goiter Goiter bruits Exophthalmus Goiter thrills
What are the treatments for Hyperthyroidism?
Three common treatment modalities are employed
Antithyroid medications
Propylthiouracil (PTU)
Methimazole (Tapazole®)
Radioactive iodine (RAI )therapy-Treatment Dose—Designed to DESTROY!!!! Surgery
Adjunctive therapies
Iodides
Adrenergic blockers – Beta -Blockers
What is the brand name of Propylthiouracil?
PTU
What is the brand name of Methimazole?
Tapazole®
What is the mechanism of action of Propylthiouracil?
PTU inhibits the peripheral conversion of T4 to T3
Inhibit the peroxidase enzyme system
How should Antihyroid medications be tapered?
Tapering:
Within 4 to 8 weeks symptoms diminish and circulating thyroid hormones return to normal
Decrease doses on a monthly basis to allow T4 to reach steady state.
Which Major AE’s are absolutely not allowed to switch between Antithyroid treatments?
- Lupus like syndrome
- Agranulocytosis - (granulocyte count < 250 mm3).
- Aplastic Anemia
Side note: More common with patients using methimazole.
What percentage of cross sensitive are between the Antithyroid medications?
50% cross-sensitivity
Whats Propylthiouracil Black Box Warning?
severe liver injury and acute liver failure
Should methimazole be given during pregnancy?
NOT in first TRIMESTER!!!
PTU is preferred the first 1 - 12wks
What is the DOC in the first 1 -12 weeks of pregnancy?
Propylthiouracil may be the treatment of choice during and just before the first trimester of pregnancy (weeks 1-12)
How should Propylthiouracil be given to pediatric patients?
Propylthiouracil is NOT recommended for use in pediatric patients (PEDs)
Why should methimazole be avoided in pregnancy?
Congenital malformations were reported approximately three times more often with prenatal exposure to methimazole compared to propylthiouracil-ONLY SAFE FOR 2ND AND 3RD TRIMESTER
What is the treatment of choice for Hyperthyroidism in the United States?
Radioactive Iodine (RAI)
How effective is Radioactive Iodine (RAI)?
Single dose 40-70% euthyroid in 6-8 weeks
What’s the RISK in using Radioactive Iodine?
Hypothyroidism will result, need for lifelong levothyroxine therapy. (May progress to this point)
Can Radioactive Iodine be used to pregnancy?
PREGNANCY IS AN ABSOLUTE CONTRAINDICATION
What is the preparation should be taken before the patient is given SURGERY for Hyperthyroidism?
Preparation for surgery usually consists of:
- PTU or methimazole for 6 to 8 weeks prior to surgery.
- Iodides (500 mg/day) for 10 to 14 days before surgery.
- Propranolol may be given adjunctively.
Why is propanolol given adjectively to surgery for hyperthyroidism?
Helps Tremor, anxiety, and HTN.
What Adrenergic Blockers are given to control the symptoms of Hyperthyroidism?
Propranolol, nadolol, and Diltiazem.
Why the mechanism of Adrenergic Blockers in light of Hyperthyroidism?
Propranolol and nadolol partially block the peripheral conversion of T4 to T3.
Diltiazem can be administered at 120 mg every 8 hours for patients who can’t receive a beta blocker
What are the adjective therapy for Hyperthyroidism?
Iodides
Adrenergic blockers
How beneficial is Iodides as adjective therapy?
Short-lived benefit, about 2-3 weeks.
Iodide is not a chronic therapy
What do large doses of Iodides do to in regards to Hyperthyroidism?
Large doses block thyroid hormone release.
Large doses inhibit thyroid hormone
Name the Iodide adjunct therapy for hyperthyroidism?
Saturated Solution of Potassium Iodide
(SSKI) 38 mg of iodide/drop.
Lugol’s solution: 6.3 mg of iodide/drop
What comes first iodine therapy (Adjunctive) or iodine therapy (RAI)?
Why?
Iodide therapy should not be given prior to radioactive iodine therapy (RAI) because it will inhibit the concentration of radioactivity in the thyroid.
What are AE of iodines?
- Rash
- Metallic taste
- Burning mouth/throat
- Sore teeth/gums
“Iodism”
- Palpitations
- -Depression
- Weight loss
- Pustular skin eruptions
Others mentioned: Gynecomastia (long term—no body Is getting this) Stomach upset Diarrhea Rhinitis Conjunctivitis
What is used to protect thyroid from radioactive iodine (I131)?
iOSAT™, ThyroSafe®, ThyroShield®
130 mg once daily, continue for 10-14 days or as directed by public officials
What are the causes of Hyperthyroidism?
Primary hyperthyroidism
- Graves’ Disease
- Toxic multinodular goiter
- Toxic adenoma
- Thyroid cancer
Thyrotoxicosis without Radioactive Iodine Uptake
- Subacute (painful) thyroiditis
- Silent (painless) thyroiditis
- Excess hormone intake (taking too much)
What’s Grave’s Disease in simple terms?
When the Thyroid gland is enlarged to 2 to 3 times normal.
- -excessive thyroid hormone
- -thyroid receptor antibody (TSHR-Sab) which has TSH-like ability to stimulate the thyroid or IgG
What’s the discription of Graves’s Disease?
TSHR-Abs stimulate orbital and fibroblastic tissue resulting in:
Ophthalmology
- -Exophthalmus
- -Proptosis
- -“Lid lag”
Dermatopathy
–Hyperpigmentation around the eyes
How long does it take Antithyroid medications to work and why?
Antithyroid medications will decrease thyroid hormone levels within 2-3 weeks (b/c of hAlf life of thyroid in the body.
What is Subacute (Painful) Thyroiditis?
Painful subacute thyroiditis is thought to be caused by a viral invasion of the thyroid parenchyma
What is the Subacute Triphasic course?
Triphasic course:
Increased serum Thyroxine and decreased TSH.
Depletion of intrathyroid hormones and TSH is elevated.
Thyroid hormone stores recover and TSH decreases.
How it Subacute (Painful) Thyroiditis treated?
Treat the pain with NSAIDs
Adrenergic blockers to manage symptoms
Self-limiting condition
When does Silent (Painless) Thyroiditis most likely occurs?
Frequently occurs during the postpartum period and patients may experience the disease with subsequent pregnancies
Self-limiting condition
What is the golden rule in treating Hyperthyroidism in Pregnancy?
Use the smallest possible dose of antithyroid medication.
Propylthiouracil (PTU) for the first trimester.
Switch to methimazole for the final two trimesters.
What is Thyroid Storm (Thyrotoxicosis)?
Life-threatening medical emergency presenting with: Delirium Coma High fever (>103oF) Vomiting Nausea Tachycardia Dehydration
How long does Thyroid Storm (Thyrotoxicosis) last?
The average duration is 72 hours but it can last up to eight days if treatment is not aggressive
How should we treat Thyroid Storm?
PTU in large doses, 900-1200 mg/day in four to six divided doses, is the preferred agent. (or Methimazole)
Who’s at risk to get thyroid disease?
Females are 4 to 8 times more likely than males to develop thyroid disease
Do children need thyroid hormones?
Children - critical for normal growth and development
What are the Principle Thyroid Function Tests?
TSH and FT4 (Free Thyroxine)
What’s the single most useful test to confirm the diagnosis of hypothyroidism?
TSH
What test of Autoimmunity confirm Hyperthyroidism?
TSH Receptor-Stimulating Antibodies (TSHR-SAb, TSHR-Ab, TRAb) IgG
Graves’ Disease
What test of Autoimmunity confirm Hypothyroidism?
Antithyroid Peroxidase Antibody (Anti-TPOAb, AMA)
Hashimoto’s Thyroiditis