SumExam1 Flashcards
(78 cards)
Levothyroxine is what kind of drug?
thyroid hormone replacement
How would you treat hypothyroidism?
with thyroid hormone
Levothyroxine*= watch for too much- hyperthyroidism
How would you treat hyperthyroidism?
block thyroid or inhibit TSH-
Thionamides*
- watch for too little hypothyroidism
How could you describe levothyroxine?
Synthetic pre of T4 identical to naturally occurring hormone
What is unique about the half life of levothyroxine and the therapeutic index
A very narrow therapeutic index and a half life of 7 days
How long would it take levothyroxine to get to a steady state?
Steady state=4-5 half lives
Half life=7 days
About a month for steady state
If there is a cardiac patient, why would you need to watch them for thyroid issues?
Because some of the signs and symptoms of hypo//hyper are heart related
What type of medications/ foods would you want to avoid while taking levo?
anything that would effect absorption in the stomach- calcium, magnesium, antacids and Warfarin
What is the importance of iodine in the thyroid?
Iodine goes into the cell and is oxidized- iodination of tyrosine happens and then makes MIT and DIT which join together and create T3 (DIT +MIT) and T4 (DIT+DIT)
What two prototype drugs are considered thionamides?
Methimazole 1st line
and propylthiouracil 2nd line
Which prototype drug is an iodine product?
potassium iodide SSKI
What two routes can Levo be given?
Oral and IV
What is a contraindication for Levo?
It can cause cardiac stimulation
What 3 things would you monitor for someone on Levothyroxine?
hyer/hypothyroidism
T4
TSH
What time of day should someone take levothyroxine?
in the morning, either 30 min before breakfast, or 60 mins after
What is the main function of thionamides?
To suppress the synthesis of thyroid hormones
If a woman was pregnant or breastfeeding, which thionamide would be better for her to take and why?
propylthiouracil (PTU)
Has lower transplacental passing and lower levels in breast milk
What is the half-life of the thionamides?
methimazole has a half-life of 6-13 hours
PTU has a half-life of 1-2 hours
In terms of ease and remembering to take it, which thionamide would be easier ? why?
Methimazole- because you only have to take it once a day for maintenance and 1-3 for initial
PTU is 3-4 initial and 2-3 maintenance
What are the adverse effects of methimazole that need to be watched?
agranulocytosis, neonatal hypothyroidism if given in pregnancy
What are the adverse effects of PTU?
Liver injury, argranulocytosis and rash
What are the two most common products for iodine therapy?
Lugol’s solution
saturated solution of iodide solution
what is the biggest complaint of iodine therapy?
tastes terrible- brassy taste, sore teeth
What are the risks factors for a higher WTH ratio?
Cardiovascular problems
hypertension
diabetes
increased mortality