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Tetrahydrozoline

Coolio

Greenlighter
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Feb 29, 2004
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Anyone here know anything about the pharmacology of tetrahydrozoline? It's the active ingredient in Visine. It's a vasoconstrictor when applied to the eyes, but what does it do when ingested orally? Is it an alpha-adrenergic antagonist? If so, what kind of subjective effects would this have?
 
Ok this isn't exactly the most scientific of responses, but I have always been told that certain types of eye drops (nicknamed 'knock out drops') can be used to knock someone unconcious if ingested orally, even in tiny amount. It's quite possible that this is completely wrong as it's only hearsay.
 
TETRAHYDROZOLINE (TETRYZOLINE)

Properties:

Main: It's a hypertensor and vasoconstrictor (due to its alpha sympathomimetic properties).
Secondary: Dopamine receptors antagonist, which causes sedative effects on the CNS.
 
jasoncrest, any idea what the subjective effects would be like?
 
Probably none is my geuss. Otherwise you would have seen it replace ephedrine... just a geuss:

On the other hand, it could kill you:

"A recent review in the Journal of Emergency Medicine concluded that ingestion of small doses of topical imidazolines can lead to significant morbidity (1). We would like to add supporting evidence to that review by reporting a case in which an unknowing ingestion of less than 15 mL of 0.05% tetrahydrozoline by a 16-year-old boy resulted in symptomatic sinoatrial node arrest."
 
^^ Yikes, and yet its now the replacement for oxymetazoline in eyedrops today.
 
mepat1111 said:
Ok this isn't exactly the most scientific of responses, but I have always been told that certain types of eye drops (nicknamed 'knock out drops') can be used to knock someone unconcious if ingested orally, even in tiny amount. It's quite possible that this is completely wrong as it's only hearsay.


^That sounds more like atropine eyes drops. Frequently used in medicine.

http://en.wikipedia.org/wiki/Atropine

[Depends what the definition of "knock out" is, but at high doses could certainly cause someone to fall over/hallucinate/death - not a nice compound]
 
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The term "knock out drops" refers to something entirely different. They're not even in production today.
 
Do you mean chloral hydrate?

"Knock out drops" is a fairly ambiguous term. It could well have been re-applied or used as slang to another drug/formulation/eye drop etc.
 
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