T3-Thyroid Medications-MJ Flashcards
Discuss the patho of hypothyroidism.
- Hypothalamus produces TRH
- TRH stimulates anterior pituitary to produce TSH
- TSH stimulates thyroid to produce T3 and T4
- Negative feedback occurs when T3 and T4 are being made to tell the ant. pit. to STOP releasing TSH
If thyroid levels are too low, then ___ should rise to stimulate the thyroid to make more.
TSH
What does the thyroid hormone do?
Regulates metabolism
Growth and development (bones, brain, etc)
What are the two types of HYPOthyroidism?
Cretinism
Myxedema
What age group is cretinism in?
Neonates and infants
What are the characteristics of cretinism?
Mental retardation Short stature and skeletal abnormalities Coarse facial features Enlarged tongue Umbilical hernia
Why would an neonate or infant have cretinism? (4 possible reasons)
- Maternal hypothyroidism (1st trimester)
- Thyroid agenesis
- Dyshormonogenic
- Iodine deficiency
Cretinism: Why does maternal hypothyroidism effect an infant?
This must be treated VERY early. If a mother has this and doesn’t realize she does then it can cause permanent neuropsychologic effects in the child. This is because during the first trimester the baby cannot produce its own thyroid hormone.
Cretinism: What is thyroid agenesis?
The baby is born without a thyroid
What age group is myxedema in?
Older children and adults
What are the clinical features of myxedema? (11)
CC-FH-MWMW-SOB-SOB
Cold intolerance Constipation Fatigue Hypercholesterolemia Myxedema Weight gain (despite normal appetite) Muscle Weakness Shortness of breath Slowing of mental activity Oligomenorrhea Bradycardia
What are the causes of myxedema (3)?
- Iodine deficiency
- Hashimoto thyroiditis (immune system attacks thyroid)
- Lithium
What is the thyroid function test that is useful for diagnosing HYPERthyroidism?
Total T3
What is the thyroid function test that is useful for diagnosing HYPOthyroidism?
TSH (highly sensitive)
What is the drug of choice that can be given for all types of thyroidism?
Levothyroxine