Treatment of Thyroid Disorders Flashcards
Symptoms of hyperthyroidism?
High BMR
Anxiety
insomnia
Eyelid retraction
Hand tremors
Excessive sweats
Goitre
What are two common manifestation of hyperthyroidism?
Diffuse toxic goitre- autoimmune disorder where antibodies to the TSH receptor stimulate thyroxine secretion
Toxic nodular goitre- benign neoplasm/ adenoma
What are the causes of hyperthyroidism?
Graves disease
Overtreatment with thyroxine
Thyroid adenoma
Transient neonatal thyrotoxicosis (mother with Graves disease)
What investigations can you do to test for thyroid disorders?
Measure blood TSH, free T3 and T4 levels
Test for anti-thyroid antibodies
Radionucleotide thyroid scan
How does graves disease appear on radionucleotide scan?
Enlarged darker area of thyroid
How does subacute thyroiditis appear on scan?
Does not appear
How does follicular adenoma appear on scan?
Circular dark spot
What is the the treatment of hyperthyroidism?
Radioactive iodine
Anti-thyroid drugs
Surgery
What are the con and pros of hyperthyroidism?
None is optimal
None interrupts the autoimmune process
Each has a drawback
No other research options so far
Describe the use of radioactive iodine?
Radioiodine is given orally
Given as a single dose and lasts about 2 months
It damages cells by emitting short range beta radiation and affects only the follicle cells
Hypothyroidism will eventually occur which can be treated with replacement therapy
What drugs are used to treat hyperthyroidism?
Thioureylenes
Carbimazole (methimazole)
Propylthiouracil
Iodine
Beta blockers
Calcium supplements
Mechanism of Thioureylenes, Carbimazole (methimazole), Propylthiouracil
Decrease the synthesis of thyroid hormones
Inhibit thyroid peroxidase so reducing the iodination of thyroglobulin
Acts over 3-4 weeks.
Mechanism of iodine?
Given orally in high doses and is converted to iodide and transiently reduced thyroid hormone secretion and vascularity of the gland
Why would you give calcium supplements?
Maintenance of normal bone density
What thioamides are given?
Carbimazole
Methimazole
Both inhibit thyroid peroxidase
Symptoms of hypothyroidism?
Low metabolic rate
Slow speech
Deep hoarse voice
Lethargy
Bradycardia
Sensitivity to cold
Mental impairment
Thickening of skin
Cretinism in children
What does myxedema refer to?
Dermatological changes associated with both hyperthyroid and hypothyroid conditions
Accumulation of increased amounts of hyaluronic acid and chondroitin sulfate in the dermis in both lesioned and normal skin causing swelling/puffiness of the subcutaneous skin tissue
What level are low in hypothyroidism?
Low T4
Possible low T3
Raised TSH (unless pituitary problem!)
Possibly various anti-thyroid antibodies
What are the congenital causes of hypothyroidism?
Hypoplasia
Familial enzyme defects
Iodine deficiency
Intake of goitrogens during pregnancy
Pituitary defects
Idiopathic
What are the acquired causes of hypothyroidism?
Iodine deficiency
Auto-immune thyroiditis
Thyroidectomy or RAI therapy
TSH or TRH deficiency
Medications
Idiopathic
Describe Hashimoto’s disease?
Most common cause of hypothyroidism
Autoimmune lymphocytic thyroiditis
Anti-thyroid antibodies
Females>males
Runs in families
What are the anti-thyroid antibodies?
Thyroglobulin
Microsomal Ab/Thyroid peroxidase
TSH-R Ab
Drugs used in hypothyroidism?
Levothyroxine
Liothyronine
Describe levothyroxine?
Synthetic analogue of thyroxine
Has all actions of endogenous thyroxine
Standard T4 replacement therapy for hypothyroidism
