Thyroid disorders

Hypothyroidism

Hypothyroidism Hypothyroidism is a disorder with multiple causes in which the thyroid fails to secrete an adequate amount of thyroid hormone. Common causes of hypothyroidism are autoimmune disease, surgical removal of the thyroid, and radiation treatment.

CAUSES AUTOIMMUNE DISEASE protects Immune system Against bacterial and viral "invaders." In autoimmune diseases, Attacks immune system Normal part of the body In autoimmune hypothyroidism, immune system Attacks Thyroid cells Cells inflamed and damaged interfering with their ability to make thyroid hormone

SURGICAL REMOVAL OF PART OR ALL OF THE THYROID The most common form of autoimmune hypothyroidism is called Hashimoto’s disease. SURGICAL REMOVAL OF PART OR ALL OF THE THYROID Part or the entire thyroid removed Thyroid nodules, Thyroid cancer, or Graves' disease Hypothyroidism results when the entire thyroid is removed or when the remaining thyroid tissue no longer works properly.

RADIATION TREATMENT Graves' disease, nodular goiter, or thyroid cancer Treated with radioactive iodine (131I) destroys the thyroid Hypothyroidism

Causes Cont………………….. CONGENITAL (FROM BIRTH) HYPOTHYROIDISM MEDICINES Lithium (most common) Amiodarone (Antiarrythmic), interferon alpha, and interleukin-2 TOO LITTLE OR TOO MUCH IODINE DAMAGE TO THE PITUITARY GLAND The pituitary gland tells the thyroid how much hormone to make.

Typical Thyroid Hormone Levels in Thyroid Disease TSH T4 T3 Hypothyroidism High Low Low Hyperthyroidism Low High High

Case 1 M.W., a 70-kg, 23-year-old voice student, thinks that her neck has become “fatter” over the past 3 to 4 months. She has gained 10 kg, feels mentally sluggish, tires easily, and finds that she can no longer hit high notes. Physical examination reveals puffy facies, yellowish skin, delayed DTRs, and a firm, enlarged thyroid gland. Laboratory data include FT4, 0.6 ng/dL (normal, 0.7– 1.9); TSH, 60 μunits/mL (normal, 0.5–4.7); and TPO antibodies, 136 IU/L (normal,<1). Hashimoto’s thyroiditis. Free thyroxine ( FT4) , Thyroid-stimulating hormone ( TSH), Thyroid peroxidase (TPO) DTR =  deep tendon reflexes

Assess M.W.’s thyroid status based on her clinical and laboratory findings. Thyroid antibodies: Antithyroid peroxidase and antithyroglobulin autoantibodies ………TPO ( …………. hashimoto’s disease ) According to the patient results ! He has low T4 and high TSH ……………………………………. Hypothyroidism

Classify hypothyroid disorders. (hypothyroidism disorders ) A Classify hypothyroid disorders ? (hypothyroidism disorders ) A. Hashimoto’s disease: Most common hypothyroid disorder i. Autoimmune-induced thyroid injury resulting in decreased thyroid secretion ii. Disproportionately affects women more than men B. Surgery or radioiodine induced (iatrogenic) C. Iodine deficiency or excessive intake D. Secondary causes i. Pituitary insufficiency (lack of TSH secretion) ii. Drug induced (e.g., amiodarone, lithium) This patient has hashimoto’s disease

Sings and symptoms consistent with hypothyroidism ? Subjective? thinks that her neck has become “fatter” over the past 3 to 4 months. She has gained 10 kg, feels mentally sluggish, tires easily, and finds that she can no longer hit high notes. Objective ? reveals puffy facies, yellowish skin, delayed DTRs, and a firm, enlarged thyroid gland. Can say Laboratory data as an objective parameters include FT4, 0.6 ng/dL (normal, 0.7– 1.9); TSH, 60 μunits/mL (normal, 0.5–4.7); and TPO antibodies, 136 IU/L (normal,<1).

Sings and symptoms Hyperthyroidism Hypothyroidism a.Weight loss/increased appetite b. Lid lag c. Heat intolerance d. Goiter e. Fine hair f. Heart palpitations/tachycardia g. Nervousness, anxiety, insomnia h. Menstrual disturbances (lighter or more infrequent menstruation, amenorrhea) i. Sweating or warm, moist skin j. Exophthalmos, pretibial myxedema in Graves disease a. Cold intolerance b. Dry skin c. Fatigue, lethargy, weakness d. Weight gain e. Bradycardia f. Slow reflexes g. Coarse skin and hair h. Periorbital swelling i. Menstrual disturbances (more frequent or longer menstruation, painful menstruation, menorrhagia)

Goal of therapy ? Therapy Goals for Both Hyperthyroid and Hypothyroid Disorders 1. Minimize or eliminate symptoms, improve quality of life 2. Minimize long-term damage to organs. 3. Normalize free T4 and TSH concentrations.

write 3 goals when treating patient with thyroid disorder ?

Hyperthyroidism

Hyperthyroidism Hyperthyroidism refers to excess synthesis and secretion of thyroid hormones by the thyroid gland, which results in accelerated metabolism in peripheral tissues

S.K., a 48-year-old woman, is admitted to the hospital for a possible MI. Her complaints include chest pain that is unrelieved by NTG, increasing SOB with exercise, nervousness, palpitations, muscle weakness, weight loss despite an increased appetite, and epistaxis; she also bruises easily. She has a history of deep venous thrombosis treated with warfarin (Coumadin) 5 mg/day; her last prothrombin time (PT) was 18 seconds (normal, 10.5–12.1), and an international normalized ratio (INR) was 1.8 (normal, 1; therapeutic, 2–3). She has angina, treated withNTG0.4 mg, and CHF, treated with digoxin (Lanoxin) 0.25 mg/day.

Physical examination reveals a thin, flushed, hyperkinetic, nervous woman. Blood pressure (BP) is 180/90 mmHg; pulse is 130 beats/minute, irregularly irregular; respiratory rate is 30 breaths/min; and temperature is 37.5◦C. Other pertinent findings include a lid lag with stare, proptosis with tearing, a diffusely enlarged thyroid gland without nodules, a bruit in the left lobe of the thyroid, positive jugular venous distention (JVD), bibasilar rales, warm moist skin with multiple bruises, new-onset atrial fibrillation (AF), slight diarrhea, hepatomegaly, acropachy, 2+ pitting edema, a fine tremor, proximal muscle weakness, and irregular scant menses

Laboratory data FT4, 2.9 ng/dL (normal, 0.7–1.9); TSH,<0.5 μunits/mL (normal, 0.5–4.7); RAIU at 24 hours, 80% (normal, 5%–35%); PT, 40 seconds (normal, 10.5–12.1); INR, 4.8 (normal, 1; therapeutic, 2–3); TPO, 200 IU/mL (normal,<1); alkaline phosphatase, 200 units/L (normal, 41–133); total bilirubin, 1.1 mg/dL (normal, 0.1–1.2); AST, 60 units/L (normal, 7–26); and alanine aminotransferase (ALT), 55 units/L (normal, 3–23). A scan shows a diffusely enlarged gland, three to four times normal size.

Assess M.W.’s thyroid status based on her clinical and laboratory findings. ? FT4, 2.9 ng/dL (normal, 0.7–1.9); TSH,<0.5 μunits/mL (normal, 0.5–4.7);

Elevated if thyroid gland is actively and excessively secreting T4 and/or T3 Radioactive iodine (Graves disease, TSH-secreting adenoma, toxic adenoma, multinodular goiter) Uptake is suppressed in disorders caused by thyroiditis or hormone ingestion. RAIU at 24 hours, 80% (normal, 5%–35%)………..(Elevated ) BesideTPO … this patient has Grave’s disease

Signs and symptoms support diagnosis of hyperthyrodism in this patient ? include chest pain that is unrelieved by NTG, increasing SOB with exercise, nervousness, palpitations, muscle weakness, weight loss despite an increased appetite, and epistaxis; she also bruises easily. Blood pressure (BP) is 180/90 mmHg; pulse is 130 beats/minute, irregularly irregular; respiratory rate is 30 breaths/min a lid lag with stare, proptosis with tearing, a diffusely enlarged thyroid gland without nodules, a bruit in the left lobe of the thyroid, positive jugular venous distention (JVD), bibasilar rales, warm moist skin with multiple bruises, new-onset atrial fibrillation (AF), slight diarrhea, hepatomegaly, acropachy, 2+ pitting edema, a fine tremor, proximal muscle weakness, and irregular scant menses FT4, 2.9 ng/dL (normal, 0.7–1.9); TSH,<0.5 μunits/mL (normal, 0.5–4.7); RAIU at 24 hours, 80% (normal, 5%–35%); PT, 40 seconds (normal, 10.5–12.1); INR, 4.8

Sings and symptoms Hyperthyroidism Hypothyroidism a.Weight loss/increased appetite b. Lid lag c. Heat intolerance d. Goiter e. Fine hair f. Heart palpitations/tachycardia g. Nervousness, anxiety, insomnia h. Menstrual disturbances (lighter or more infrequent menstruation, amenorrhea) i. Sweating or warm, moist skin j. Exophthalmos, pretibial myxedema in Graves disease a. Cold intolerance b. Dry skin c. Fatigue, lethargy, weakness d. Weight gain e. Bradycardia f. Slow reflexes g. Coarse skin and hair h. Periorbital swelling i. Menstrual disturbances (more frequent or longer menstruation, painful menstruation, menorrhagia)

Classification Toxic diffuse goiter (Graves disease) i. Autoimmune disorder ii. Thyroid-stimulating antibodies directed at thyrotropin receptors mimic thyroid-stimulating hormone (TSH) and stimulate triiodothyronine/thyroxine (T3/T4) production.

Classification Pituitary adenomas: Excessive TSH secretion that does not respond to normal T3 feedback

Classification Toxic adenoma “Hot” nodule in thyroid, autonomous of pituitary and TSH

Classification Toxic multinodular goiter (Plummer disease): Autonomous follicles, if large enough, cause excessive thyroid hormone secretion.

Classification Painful subacute thyroiditis: Self-limiting thyroiditis caused by viral invasion of the thyroid parenchyma, resulting in release of stored hormone Drug induced (e.g., excessive thyroid hormone use, amiodarone)

Goal of therapy ? Therapy Goals for Both Hyperthyroid and Hypothyroid Disorders 1. Minimize or eliminate symptoms, improve quality of life 2. Minimize long-term damage to organs. 3. Normalize free T4 and TSH concentrations.

differences between T3 and T4 ?

S. No. T3 T4 1. L-3,5,3'-triiodothyronine Thyroxine/ L-3,5,3',5'-tetraiodothyronine 2. Active hormone T4 is produced by thyroid gland and is converted into T3 in the liver. 3. T3 is less common than T4 T4 is more common than T3 4. More potent Less potent

Radioactive iodine. Taken by mouth, radioactive iodine is absorbed by your thyroid gland, where it causes the gland to shrink and symptoms to subside, usually within three to six months. Because this treatment causes thyroid activity to slow considerably, causing the thyroid gland to be underactive (hypothyroidism), you may eventually need to take medication every day to replace thyroxine. Used for more than 60 years to treat hyperthyroidism, radioactive iodine has been shown to be generally safe.

Treatments of hyperthyroidism Anti-thyroid medications. These medications gradually reduce symptoms of hyperthyroidism by preventing your thyroid gland from producing excess amounts of hormones. They include propylthiouracil and methimazole (Tapazole). Symptoms usually begin to improve in six to 12 weeks, but treatment with anti-thyroid medications typically continues at least a year and often longer. For some people, this clears up the problem permanently, but other people may experience a relapse.

Both drugs can cause serious liver damage, sometimes leading to death Both drugs can cause serious liver damage, sometimes leading to death. Because propylthiouracil has caused far more cases of liver damage, it generally should be used only when you can't tolerate methimazole. A small number of people who are allergic to these drugs may develop skin rashes, hives, fever or joint pain. They also can make you more susceptible to infection.

Beta blockers. These drugs are commonly used to treat high blood pressure. They won't reduce your thyroid levels, but they can reduce a rapid heart rate and help prevent palpitations. For that reason, your doctor may prescribe them to help you feel better until your thyroid levels are closer to normal. Side effects may include fatigue, headache, upset stomach, constipation, diarrhea or dizziness.

Surgery (thyroidectomy) Surgery (thyroidectomy). If you're pregnant or otherwise can't tolerate anti-thyroid drugs and don't want to or can't have radioactive iodine therapy, you may be a candidate for thyroid surgery, although this is an option in only a few cases.

In a thyroidectomy, your doctor removes most of your thyroid gland In a thyroidectomy, your doctor removes most of your thyroid gland. Risks of this surgery include damage to your vocal cords and parathyroid glands — four tiny glands situated on the back of your thyroid gland that help control the level of calcium in your blood. In addition, you'll need lifelong treatment with levothyroxine (Levoxyl, Synthroid, others) to supply your body with normal amounts of thyroid hormone. If your parathyroid glands also are removed, you'll need medication to keep your blood-calcium levels normal.

Treatment of hypothyroidism Standard treatment for hypothyroidism involves daily use of the synthetic thyroid hormone levothyroxine (Levothroid, Synthroid, others). This oral medication restores adequate hormone levels, reversing the signs and symptoms of hypothyroidism. One to two weeks after starting treatment, you'll notice that you're feeling less fatigued. The medication also gradually lowers cholesterol levels elevated by the disease and may reverse any weight gain. Treatment with levothyroxine is usually lifelong, but because the dosage you need may change, your doctor is likely to check your TSH level every year

References Koda Kimble , applied therapeutics Pharmacotherapy Bedside Guide Christopher P. Martin, Robert L. Talbert Updates in Therapeutics: The Pharmacotherapy Preparatory Review VI. American Association of Clinical Endocrinologists: AACE

HW Define hypothyroidism and hyperthyroidism What are the cause of hypothyroidism What are the causes of hyperthyroidism How can you Diagnose hypothyroidism and hyperthyroidism What are the symptoms of hyperthyroidism What are the symptoms of hypothyroidism

What are the goals of therapy for hyperthyroidism and hypothyroidism What are the Complications of hypothyroidism What are the Complications of hyperthyroidism What are the goals of therapy for hyperthyroidism and hypothyroidism What are the medications that used for the treatment of hyperthyroidism and hypothyroidism