Pharm2 3 Thyroid pt1 Flashcards
The thyroid glands function is to regulate
the bodies metabolism
3 hormones produced by thyroid gland
Thyroxine (T4)
Triodothyronine (T3)
Calcitonin
The pituitary gland is under control by the ___ which secretes __
hypothalamus
TSH Releasing Hormone (TRH)
If history and physical shows signs of thyroid disease, test what?
TSH
What is thyroid hormone’s target tissue?
There is no particular target tissue for thyroid hormone
Every cell in body is affected by the thyroid hormones
Excessive thyroid hormones (T3,T4) can manifest themselves as (6 example symptoms)
hypertensive, sweating, febrile, tachycardic, exophthalmos, hair loss,
Thyroid storm is life threatening, with what main 3 sx?
htnsive, tachy, altered mental status
What is the most common thyroid disorder in the United States?
Autoimmune thyroiditis
What is autoimmune thyroiditis?
the body interprets the thyroid glands and its hormone products T3, T4 and TSH as threats, therefore producing special antibodies that target the thyroid’s cells, thereby destroying it
It presents with hypothyroidism or hyperthyroidism and the presence or absence of goiters. With goiter = Hashimotos.
Trade name for Levothyroxine: used in \_\_thyroidism Absorbed where? Take how many times a day, why? Who would need increased dose?
Synthroid,
used in Hypothyroidism.
Absorbed in GI tract
A long half life allows for once a day administration
Women on oral estrogen need increased dose of therapy
Synthroid is always written with what 3 letters on it?
DAW = dispense as written. This drug is always written as DAW. Pharmacies always try to give a trade product, instead of the generic. This one is almost always the trade name.
the biggest diff btwn commercial products and generic is:
trade can vary 5% up or down, but generic can vary by a greater percentage.
*BQ: What is the median dose for patients on Synthroid in the United States?
about 125 micrograms (0.125 mg)
If I write it for 100 micrograms and it’s branded, its range is what?
What if it’s generic?
Branded: 95-105 (the next two closes doses are 88 or 117, so it does not reach either one - safe)
Generic: 85-125 (this can branch into 88, 117, 125 doses - much less safe)
6 dosing level regiments (in micrograms) of Levothyroxine/Synthroid
75, 88, 100, 117, 125, 150 (max is 300 mcg)
What’s neat about Synthroid from the FDA’s point of view?
Synthroid’s been around for many years (late 1950’s). In 1962 the food, drug, cosmetics act was passed in the USA leading to the FDA. This drug predates the FDA, and therefore didn’t have clinical trials. FDA made them do it, but they threatened to stop manufacturing the drug, so the FDA backed off. So it’s never had clinical trials done. But it has been around so long we understand it very well.
Levothyroxine Sodium / Synthroid
Route of admin
How to administer safely
What’s the max dose?
PO (daily)
Titrate up about once a month by checking TSH, and altering accordingly
Max dose: 300 mcg
Levothyroxine/Synthroid - what is its big warning label?
3 side effects from class.
Do not use for obesity and weight loss
This can induce palpitations, tachycardia, put someone into A fib if they have a propensity
Liothyronine Sodium
When is it used? (5)
and Why?
Used in INITIAL THERAPY of myxedema, myxedema coma, short-term suppression of TSH in patients undergoing thyroid cancer surgery, and rare 5’-deiodinase deficiency (rare endocrine disorders)
B/c it has a short 1/2 life
Why would you not use Liothyronine for maintenance of thyroid hormone replacement therapy (like Synthroid/Levthyroxine)?
B/c it has a shorter 1/2 life than those.
What is Used in initial therapy of myxedema, myxedema coma, short-term suppression of TSH in patients undergoing thyroid cancer surgery, and rare 5’-deiodinase deficiency (rare endocrine disorders)?
Liothyronine
Liothyronine Sodium Route of admin Where is it absorbed? What do you monitor? Elderly?
PO
Rapidly absorbed through GI tract
Need to monitor T3 and TSH levels
Elderly need lower dose due to decreased renal function
What is Liotrix used for?
What’s important to know about this drug?
Used for thyroid hormone replacement
No data supportive that Liotrix is better then other thyroid drugs. So it’s not really used, eh?
No data supportive that __ is better then other thyroid drugs. So it’s not really used, eh?
Liotrix
