For Junior Doctors and Pharmacists
Topic: The Pathophysiology of Thyroid Hormones and Anti thyroid Medications
Remember guys, to master the topic you first need to understand the pathophysiology of
-Thyroid hormones production
-Anti thyroid medications
Follow this thread
Topic: The Pathophysiology of Thyroid Hormones and Anti thyroid Medications
Remember guys, to master the topic you first need to understand the pathophysiology of
-Thyroid hormones production
-Anti thyroid medications
Follow this thread
Thyroid synthesis
1)Iodine transport
Iodide (I-) from the blood is actively transported into the follicular lumen
1)Iodine transport
Iodide (I-) from the blood is actively transported into the follicular lumen
2)Thyroglobulin synthesis
Thyroglobulin is a protein that contains large numbers of tyrosine amino acids that go on to become individual thyroid hormone molecules. Thyroglobulin is synthesized within the follicular epithelial cell and secreted into the follicular lumen.
Thyroglobulin is a protein that contains large numbers of tyrosine amino acids that go on to become individual thyroid hormone molecules. Thyroglobulin is synthesized within the follicular epithelial cell and secreted into the follicular lumen.
3)Thyroid peroxidase
- Enzyme in the acellular colloid of the follicular lumen
- First it generates I2 by oxidizing I- ions
- Then it will generate monoioodotyrosine (MIT) and Diiodotyrosine (DIT)
- Peroxidase then combined with MIT and DIT -> T3,T4
- Enzyme in the acellular colloid of the follicular lumen
- First it generates I2 by oxidizing I- ions
- Then it will generate monoioodotyrosine (MIT) and Diiodotyrosine (DIT)
- Peroxidase then combined with MIT and DIT -> T3,T4
4)Release of T4 and T3 from thyroglobulin
Now you understand? I’m trying to make it as simple as I can. Next thread I will be taking on each medication used for hyperthyroidism and their mechanism of action.
Now you understand? I’m trying to make it as simple as I can. Next thread I will be taking on each medication used for hyperthyroidism and their mechanism of action.
1)Carbimazole
- 10 X more potent than PTU
- Inhibit the thyroid peroxidase- catalyzed reactions and blocking iodine organification
- Block coupling of iodotyrrosines
- Carbimazole does not affect the peripheral deiodinase D1 that converts T4 to T3
- 10 X more potent than PTU
- Inhibit the thyroid peroxidase- catalyzed reactions and blocking iodine organification
- Block coupling of iodotyrrosines
- Carbimazole does not affect the peripheral deiodinase D1 that converts T4 to T3
2)Propylthiouracil
- Inhibit the thyroid peroxidase- catalyzed reactions and blocking iodine organification
- Block coupling of iodotyrrosines
- Inhibit peripheral deiodinase D1 that converts T4 to T3
- Inhibit the thyroid peroxidase- catalyzed reactions and blocking iodine organification
- Block coupling of iodotyrrosines
- Inhibit peripheral deiodinase D1 that converts T4 to T3
3)Potassium iodide
- Inhibit hormone release from the thyroid gland
- Interferes with synthesis of thyroid hormones by inhibiting thyroid peroxidase
- Inhibit hormone release from the thyroid gland
- Interferes with synthesis of thyroid hormones by inhibiting thyroid peroxidase
4)Beta blocker
- Not an antithyroid medications
- Inhibit the peripheral conversion from T4 to T3
- Not an antithyroid medications
- Inhibit the peripheral conversion from T4 to T3
Now let us step it up a notch, we are trying to apply it on clinical situation. If you have a thyroid storm patient, How would you manage the patient?
Management of thyroid storm
Approach considerations
-Supportive measures
-Antiadrenergic medications
-Thionamides
-Iodine preparation
-Glucocorticoids
-Bile acid sequestrants
-Treatment of underlying condition
-Rarely plasmapheresis
Approach considerations
-Supportive measures
-Antiadrenergic medications
-Thionamides
-Iodine preparation
-Glucocorticoids
-Bile acid sequestrants
-Treatment of underlying condition
-Rarely plasmapheresis
Supportive measures
- Supplemental oxygen, ventilatory support and intravenous fluids
- Correct electrolyte abnormalities
- Treat cardiac arrhythmia
- Aggressively
- Control hyperthermia by applying ice packs and cooling blankets
- Supplemental oxygen, ventilatory support and intravenous fluids
- Correct electrolyte abnormalities
- Treat cardiac arrhythmia
- Aggressively
- Control hyperthermia by applying ice packs and cooling blankets
Antiadrenaergic drugs
- Propranolol 60-80 mg every 4-6 hours
- Dose need to be adjusted according to heart rate and blood pressure
- Calcium channel blocker maybe use when beta blockers are contraindicated
- Propranolol 60-80 mg every 4-6 hours
- Dose need to be adjusted according to heart rate and blood pressure
- Calcium channel blocker maybe use when beta blockers are contraindicated
Thionamides
- PTU 200 mg every 4 hours
Iodine compounds
- Lugols iodine 10 drops every 8 hours
- PTU 200 mg every 4 hours
Iodine compounds
- Lugols iodine 10 drops every 8 hours
Glucocorticoids
- It decrease peripheral conversion from T4-> T3
- It is also helpful in preventing relative adrenal insufficiency due to hyperthyroidism and improving vasomotor symptoms.
- IV hydrocortisone 100 mg every 8 hours or dexamethasone at dose of 1-2 mg every 6 hours
- It decrease peripheral conversion from T4-> T3
- It is also helpful in preventing relative adrenal insufficiency due to hyperthyroidism and improving vasomotor symptoms.
- IV hydrocortisone 100 mg every 8 hours or dexamethasone at dose of 1-2 mg every 6 hours
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