In chapter seven we begin to talk about our endocrine system, and in this video specifically, we will be talking about our
hyperthyroid agents.
The main
categories that we'll be discussing in this video are going to be our tioamides and then two different types of iodine - we have our radioactive
iodine and our non-radioactive iodine. Our thioamides can be broken down into two different drugs -
we have our methimazole and
the brand for that is Tapazole, and then we also have our propylthiouracil
which is commonly just abbreviated as PTU. Our two different types of iodine as
previously mentioned are our radioactive iodine, commonly referred to as Radioiodine, and
then our non-radioactive iodine, commonly referred to as
Lugol's Solution.
Our first question is:
'Which medication is the safest for administration and does not lead to tolerance?'
A) thioamide - methimazole (Tapazole)
B) thioamide - propylthiouracil (PTU)
C) radioactive iodine (Radioiodine)
D) non-radioactive iodine (Lugol's Solution)
That's going to be A) methimazole. It's going to be our safest option that does not lead to tolerance.
B) propylthiouracil
and C) radioactive iodine are going to be the two options on this list that are going to have the highest
side-effect profile.
B) propylthiouracil or PTU has a black box warning for some hepatotoxicity, and
C) radioactive iodine isn't really going to be the safest option either because it can lead to
thyroid destruction - essentially that's its main role is thyroid destruction so that can lead to some serious
consequences as well.
While D) non-radioactive iodine is a safer route than our PTU or radioactive iodine, it can lead to tolerance
So that's why D) is incorrect in this
question.
Our next question is going to relate to PTU or propylthiouracil.
The question states: 'Which of the following medications is administered several times per day
for maintenance therapy and is associated with hepatotoxicity?'
When talking about maintenance therapy, there are two medications on this list that we do NOT use for maintenance,
and that's going to be both of our iodine - our radioactive iodine and our non-radioactive iodine.
Our maintenance therapy medications are going to be limited to our methimazole or propylthiouracil.
When it comes to maintenance, our methimazole is going to be used just once a day, and
PTU or propylthiouracil is going to be used three times a day and
it does have that black box warning for hepatotoxicity as well.
The next question here is going to be relating our
radioactive iodine and that question is: 'Which medication destroys the thyroid gland and can lead to over-correction of hyperthyroidism?'
It's going to be C) radioactive iodine. It's going to work to specifically destroy the thyroid gland, and
there's no specific known amount that it's going to destroy until the patient comes back for a check-up, and
the radioactive Iodine might destroy too much of the thyroid gland and that could lead to a patient becoming
hypothyroid and needing to take synthetic thyroid to correct for that long term.
So C) would be the correct answer in this case.
Methimazole and propylthiouracil
are going to work to inhibit thyroid hormone formation, and
non-radioactive Iodine is going to work as a negative feedback on the formation of thyroid hormones
The last question that we have here is going to discuss the implications that non-radioactive iodine
has on hyperthyroidism and that question is: 'Which medication is administered in drops and is used as an adjunct therapy for hyperthyroidism?'
So A) and B), methimazole and propylthiouracil,
are both tablets, and
they're mainstay therapies for patients that have hyperthyroidism.
C) radioactive iodine comes in either a capsule or liquid formula,
and that is also going to be a mainstay therapy for patients with hyperthyroidism.
D) non-radioactive iodine
is going to be a solution that is administered in drops, however
this is going to be an adjunct therapy for patients with hyperthyroidism.
Commonly, it's used leading up to before the patient has their thyroid gland removed for surgery is typically when this medication is used.