Drugs For Thyroid Disorders (61) Flashcards
Thyroid gland secrets what two hormones?
Triiodothyronine and thyroxine
-T3 and T4
Primary vs secondary hypothyroidism
Primary: abnormality in thyroid itself
Secondary: other body system dysfunction
Examples of secondary hypothyroidism
-pituitary gland dysfunction and not secreting TSH
-hypothalamus does not secrete TRH
Hypothyroidism in newborn and infants
Cretinism
Cretinism
-low metabolic rate
-Dec growth and sexual development
-mental retardation
Symptoms of hypothyroidism in adults
-firm edema
-Dec metabolic rate
-slow HR
-loss of mental/physical stamina
-loss of hair
Goitre
-enlargement of thyroid gland
-overstimulation due to high levels of TSH
-little or no TH for negative feedback
Presence of goitre can be present in both
Hyper or hypo
Levothyroxine
Treatment of hypothyroid
-synthetic thyroid hormone T4
-replacement therapy
How long does levothyroxine take for full effect
4-6 weeks
levothyroxine indication
All forms of hypothyroidism
Eg: unknown case, replacement therapy for surgical removal of gland, gland destroyed by radioactive iodine (cancer/hyperthyroidism)
MOA of levothyroxine
Works the same way that natural thyroid hormone does
AE of thyroid hormone agents
Usually drug excess
-thyrotoxicosis
Signs of thyrotoxicosis
-cardiac dysrhythmias
-insomnia, tremors, headache, anxiety
-nausea, diarrhea
-menstrual irregularities
-weight loss, sweating, heat intolerance
Treatment of hypothyroidism : need to use caution in
Conditions of cardiac disease or hypertension
Treatment of hypothyroidism is NOT
A cure
What symptoms should patients be taught to report when on hypothyroidism treatment
Chest pain or heart palpitations
When should levothyroxine be taken
30-60 minutes before breakfast
-food decreases the absorption
Types of hyperthyroidism
Graves’ disease, toxic modular goiter
Hyperthyroidism
Excessive thyroid hormone secretion
-results in thyrotoxicosis
Hyperthyroidism: thyrotoxicosis
Increased activity of multiple body systems
-heart palpitations, increased HR
-CNS stimulation (nervousness, rapid thought/speech, insomnia)
-high metabolic rate (heat intolerance, skin flushed, moist)
-muscle weakness, atrophy
-increased appetite but weight loss
Radioactive iodine (131I)
Treatment of hyperthyroidism
-works by destroying the thyroid gland
Anti thyroid drugs: thioamide derivatives
Example
Methimazole
Mathimazole
Prevent thyroid hormone synthesis
-takes 3 to 12 weeks for full effect
