a public service announcement on medication

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Veneficus

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I've never seen it, but one of my best friends has seen it twice in as many years when he moved to Texas.
 
Ven, can you help me out with this? Couldn't log into medscape so I'm just going off of the concept.

My understanding of zofran is that it controls nausea/vomiting by blocking peripheral 5ht receptors in the gut. This prevents vagus nerve stimulation from said 5ht receptors, as a contrast to first-generation antihistamines, which block centrally in the CTZ as well as peripheral vagus terminals.

Off the top of my head, I'm having a hell of a time connecting that concept to prolonged QT. Any thoughts?
 
The FDA states that the QT elongation specifically occurs with a single IV dose of 32mg and recommend that a single IV dose shouldn't exceed 16mg.

I've never seen it given any more than 8 at a time, usually 4mg. Now anytime you start giving a drug dose 8 times the normal dosing, you will start to see side effects/adverse effects. And that's with any drug. Period.

The only caveat to my earlier response would the a possible explanation. I hypothesize my friend saw those two reactions on his two little old ladies because they were cardiac pts, persistantly nauseated received multiple doses of Zofran before be showed up, and had a decreased metabolism from being "little old ladies".
 
I've heard of large doses being given to patients actively undergoing chemo, but that is the only time. And by actively, I mean sitting in the infusion room with the chemo being delivered right then.
 
Smash said:
*cough cough*

Now, I'm no farmacol, farmycaljist, pharmekaloj, pha.... Drug person, but are there any drugs out there the FDA don't put a black box warning on? Usually for QT prolongation at that?
Click to expand...

No.

You are right.

But I always love to see things like this on drugs that are supposedly "completely safe."
 
Veneficus said:
No.

You are right.

But I always love to see things like this on drugs that are supposedly "completely safe."
Click to expand...

True, it's only how much time passes before 'completely safe' becomes 'mostly safe' that varies.
That's why I go with homeopathy. Nothing is safer than taking nothing!
 
Doczilla said:
Ven, can you help me out with this? Couldn't log into medscape so I'm just going off of the concept.

My understanding of zofran is that it controls nausea/vomiting by blocking peripheral 5ht receptors in the gut. This prevents vagus nerve stimulation from said 5ht receptors, as a contrast to first-generation antihistamines, which block centrally in the CTZ as well as peripheral vagus terminals.

Off the top of my head, I'm having a hell of a time connecting that concept to prolonged QT. Any thoughts?
Click to expand...

looked it up for you.

It is not an easy answer. There is a flowchart that makes the clotting cascade look rather simple.

But basically, the ondasterone blocks peripheral 5-ht3, which blocks vagal afferents to the solitary tract nucleaus and the chemo receptor trigger zone of the area postrema, both of which synergistically affect the medula.

the sum total of receptors involved in various locations are: central and peripheral 5HT3, dopamine, muscarinic acetylcholine, endocanniboid, histamine and substance P.
 
"Safe" medicines

Anyone using the term "mother's milk" in regards to medicines, either verbally, in print or subconsciously, needs to go take care of thalidomide babies for a year.
 
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