Clinical pharmacology Thyroid disorders

Thyroid Function Tests "TSH" Test -- Thyroid Stimulating Hormone / Serum thyrotropin Under .4 can indicate possible hyperthyroidism. Over 6 is considered indicative of hypothyroidism.)

Thyroid Function Tests Free T4 / Free Thyroxin - FT4 Less than 0.7 is considered indicative of possible hypothyroidism. T3 / Serum triiodothyronine Less than 80 can indicate hypothyroidism.

Thyroid disorders Imbalance in production of thyroid hormones arises from dysfunction of the thyroid gland itself, the pituitary gland, which produces thyroid-stimulating hormone (TSH), or the hypothalamus, which regulates the pituitary gland via thyrotropin-releasing hormone (TRH). Concentrations of TSH increase with age, requiring age-corrected tests. Hypothyroidism affects between three and ten percent of adults, with incidence higher in women and the elderly. Hypothyroidism may cause cretinism and myxodema. Hyperthyroidism causes Graves’ disease.

Thyroid disorder *Hyperthyroidism is a condition in which the thyroid gland makes too much thyroid hormone,over long or short period. Causes. Getting too much iodine Graves disease Inflammation (thyroiditis). Noncancerous growths of the thyroid gland Symptoms,. Fatigue-Goiter-Heat intolerance-Increased appetite-Increased sweating-Weight loss -High blood pressure-exophthalmos-(palpitations)

Diagnosis & treatment Blood tests are also done to measure levels of thyroid hormones. TSH (thyroid stimulating hormone) level is usually low T3 and free T4 levels are usually high Treatment Antithyroid medications Radioactive iodine Surgery

Thyroid disorder Hypothyroidism Hypothyroidism is a condition in which the thyroid gland does not make enough thyroid hormone. Causes The most common cause of hypothyroidism is inflammation of the thyroid gland. Autoimmune in which the immune system attacks the thyroid gland. Other common causes of hypothyroidism include: Radiation treatments to the neck to treat different cancers Radioactive iodine used to treat an overactive thyroid.

Hypothyroidism Surgical removal of part or all of the thyroid gland. Certain drugsAmiodarone. Symptoms,:weakness,lethargy,memory loss, weight gain.hair loss, Treatment, : thyroxine replacement therapy.

Case 1 Miss SM is 25 year old with Grave disease.She was treated with carbimazole but developed severe rash, so the drug was withdrawn.Rash also occured with propylthiouracil.She is thyrotoxic with blood pressure 160/60.Pulse rate 110 bpm and very large thyroid gland.Lab test shows elevated T4.Surgery is indicated. What are the indications for surgery? What therapy would you recommend to alleviate some of her symptoms? What preoperative thyroid preparation is needed? What postoperative complications are associated with thyroidectomy

Answer 1-Surgery is the treatment of choice when malignancy is suspected, and when patient has features of local compression,as difficulty swallowing,for removal of goitre, ( cosmetic),when thionamides have caused side effects, and when patient is pregnant. 2-B-blockers, relieve tremors,palpitations, 3-All patients should be euthyroid at time of surgery to avoid rapid elevation of T4 and precipitation of thyroid crysis. She should recieve Lugol solution,B blocker, 4-Postoperative complications, are risk of anaesthesia,and surgery itself. Hypoparathyrodism,infection and poor wound healing,

Case 2 Mr BC is 66.He has been commenced on thyroxine.He has a prescription for carbamazepine too , and FeSO4 in the morning. What issues should be covered when counseling Mr BC about his medicines?

Answer There are two potential drug interactions, Ferrous sulphate has been shown to cause reduction in the effect of thyroxine in patients with hypothyrodism. So separate thyroxine and ferrous sulphate doses by two hours at least. Anticonvulsants have been reported to increase the metabolism of thyroid hormones, but this is not very important. Mr BC should attend for regular monitoring. It should be explained to him that it may be several weeks or months before symptoms are fully controlled. Mr BC should also be told that he may need lifelong therapy,it is also important to reinforce this when the patient has become asymptomatic from his thyroid disease.