00:02
Let's switch now to the urea cycle defects.
00:04
These are problems with patients
have problems getting rid of nitrogen waste.
00:10
Almost all of them are autosomal recessive
with the exception of ornithine transcarbamylase deficiency or OTC.
00:20
OTC is X-linked, which means girls get it mildly or not at all,
boys get it very badly.
00:28
This family of diseases will typically present
with increased ammonia levels and ammonia toxicity.
00:38
There is a variability in how severe it can be
but they can be quite severe.
00:43
And these patients with hyperammonemia
develop long term cognitive problems.
00:49
So treatment of these urea cycle defects
includes medicines that allow disposal of ammonia
by bypassing the urea cycle and allowing excretion of ammonia.
01:05
Drugs for these are unusual.
01:07
In other circumstances you might not even have seen these
or use these drugs before
unless you've taken care of one of these patients.
01:14
Examples would be sodium benzoate and sodium phenylbutyrate.
01:18
Sometimes we can use arginine hydrochloride
and if the meds aren't enough
and the patient is having bad ammonia crisis, we can also do dialysis.
01:28
But the key drugs are sodium benzoate and sodium phenylbutyrate.
01:33
So in the acute setting,
where a patient is coming in a very high ammonia levels.
01:39
We're gonna first stop giving any protein at all.
01:42
We want them to get no more additional nitrogen in their diet.
01:46
We're gonna give them medicines to bypass the urea cycle,
more sodium benzoate and more sodium phenylbutyrate.
01:53
But those things are a little bit different but you get the idea.
01:56
Lastly, if it's severe, we'll give them dialysis.
02:00
The idea is to completely remove that nitrogen from their body
because any minute with a high nitrogen level is really bad for their brain.
02:07
So that's all I have for you today, about all these metabolic defects.
02:12
They are incredibly complicated and challenging to remember.
02:16
And this is just an overview, but I hope it'll be enough for you
and if you review a few times I'm sure you'll get it well.
02:22
Thanks for your attention.