Thyroid Diseases (Management)

Thyroid Diseases (Management)

1. Hyperthyroidism

   • High Labs(total T4, free T4, Total T3); LOW lab(TSH)
   • Symptoms/Presentation
     • Heat intolerance Tremor Nervousness Goiter Weakness/ Insomnia Frequent bowel movement; diarrhea
     • Increased Radioactive Iodine Units(RAIU)
       • TSH related Reistance to Pitutiary TH secretion
       • TSH related
         • TSH causes the overprod of T3, T4
       • non TSH related
         • Meds Pituitary resists Thyroid hormone Various thyroid cancers Goiter(due to "fooled gland" thinking that there is  too little T3/T4; there is more than enough).
         • Graves Disease
           • This is an autoimmune disease and a common cause of increased RAIU--hyperthyroidism!
           • Thyroid Storm
             •    —high fever (often >103°F), tachycardia, tachypnea, dehydration, delirium, coma, nausea, vomiting, and diarrhea    
     • Decreased Radioactive Iodine Units
       • Cancer Inflammatory thyroid Too much outside thyroid intake Meds Food
       • Inflammatory/related to inflammation
       • Cancers
       • Food and medications
         • Amiodarone
           • Iodine makes up 37% of the weight. Can cause Type I or Type II  thyroid disease!
           • Type I
             • This is known as thyrotoxicosis:hyperthyroidism!
             • De-iodinization is lowered-->more t4 and t3 remaining
               • See MedScape Article; but  Amiodarone blocks T4 and T3 from entering the cell and ALSO stops conversion of T4 to T3 in the peripheral/other organ tissues
             • (THYROID DISEASE)
           • Type II
             • (NO THYROID DISEASE)
   • Treatments
     • SURGERY
       • Meds used pre-surgery
         • For 6 to 8 weeks Iodine is used for 1 to 2 weeks
     • Radioactive Iodine(I-131)
       • 1st Line Conditions
         • Graves' disease Nodules Goiters
       • Contraindications
         • Pregnancy and nursing mothers.
       • Adverse Effects
         • related to disease Risk Increasing
           • Thyroid Cancer Cardiovascular Disease Death (Got it? Yes, but sad nevertheless!!)
         • related to thyroid
           • radiation thyroiditis  hypothyroidism
     • Antithyroid Medications
       • Thioamides
         • Propylthiouracil(PTU)
           • Preferred Scenarios
             • Phrase that helps you remember when this should be used  Peter ran a LaP in Th(ialand) La-Lactation P-Pregnancy Th-Thyroid Storm
         • Methimazole
           • Advantages over PTU
             • Less liver issues and works faster.  Top recommended thioamide (The article on Thyroid function testing also made reference to use in patient...saw Real world application )
         • Benefits
         • Disadvantages
           • Side Effects
             • SEVERE
               • Agranulocytosis
               • Hepatitis
             • BENIGN
               • Joint Pain
               • Fever and Rash
               • leukopenia
         • USED for 1 (12 months)to 2 YEARS(24 months)
       • Iodides
         • Conditions /Indications of Use
           • Thyroid Storm
           • Severe Thyroidtoxicosis
           • Surgery
         • Contraindications
           • Pregnancy
           • Before use of Radioactive Iodine(RAI)
           • Nodular Goiters and Adenomas
     • Beta Blockers
       • Should be used until the more specific anti-thyroid medication effect takes place  The  peripheral T4 to T3 conversion (propranolol, nadolol)   is inhibited.
       • Reasons to Use
         • AKA indications and Uses/Conditions
         • management of symptoms
         • Works within hours
       • Reasons not to use
         • Also known as contraindications and precautions
         • Bronchospasm (severe)
         • Heart issues
           • 2nd or 3rd degree heart block Decompensated heart failure
         • Alternatives
           • CCBs, beta 2 antagonists and other sympatholytics CAN be used.

2. hypothyroidism

   • Treatments
     • Levothyroxine
       • Synthetic T4(AKA thyroxine)! Multiple brands are available  but these may not be therapeutic equivalent to each other.
       • Drug Interactions
         • Decrease T4 absorption
           •    ¡Cholestyramine- Brand Name (Questran) and associated products   ¡Calcium- Brand Names(Phoslo, Eliphos, Phoslyra, and Calphron)   ¡Ferrous sulfate ¡Aluminum hydroxide  ¡Sucralfate- Carafate, Orafate, and ProThelial  
         • Increase T4 metabolism
           •    ¡Rifampin- Rifadin  ¡Phenytoin- Dilantin, Phenytek and others ¡Phenobarbital- Lumina  ¡Sertraline-Zoloft
         • Pharmacodynamic effects
           • Warfarin
             • Elevated INR and bleeding risk
           • Digoxin
             • More digoxin may be needed if using levothyroxine
       • Side Effects
     • Liothyronine (Cytomel)
       • Not first line Synthetic T3/TriiodothyronineAdvantageous against myxedema coma
     • Armour Thyroid
       • Think "it varies": -Ratio of hormones varies -The products vary in potency among the brands
       • High allergy potential
     • Liotrix(Thyrolar)
       • Combination of  Synthetic T4 AND T3 It is predictable and stable NOT dispensed often though
       • Adverse reactions: Rare but clinical pharmacology does note itching, hypersensitivity and a skin rash
   • TSH, T4, T3 levels
     • TSH is high T4 and T3 are low. Note Radioactive Iodide Uptake is not used in diagnosis.
   • Causes
     • Primary
     • Secondary

3. Normal Physiology

   • TRH-->TSH-->T4 AND or T3 levels
     • high T34 or t4--> negative feedback