September 03, 2003

The Amy Sedaris Special

I was watching a rerun of Late Night with Conan O'Brien last night, and Amy Sedaris was on the show. She talked about something that will cause expolsive diarrhea when a few drops of it are added to a person's drink, but they bleeped out the substance...

One quick Google... and I found this.

Any idea why it works, E Lo?

Posted by wadsbone at September 3, 2003 11:48 PM

Well, yes and no. One formulation of Visine, Visine Advanced Relief, contains Polypropylene Glycol. Why, I'm not sure, because the only on-label indication for PEG is as a cathartic laxative for colonic preparation for endoscopy. BUT (butt?) -- Visine AR is 1% PEG, and the solution used for colonic prep is 6%. "But wait!" you say. "It's less concentrated, but if you put enough Visine in their food, there'd be explosive diarrhea for sure!" Maybe, if you gave enough of it. Here's an idea how much would be enough: for colonic prep, the indicated dose is 25-40 mL/kg/hour of the 6% soln. Using the standard 70 kg man model, which is what dosing is based on in medicine, that's 1750-2800 mL of 6% solution in one hour. So that would be 10.5 - 16.8 LITRES (spelling to take Wadsbone on a magical trip to yester-year and his European Excursion) of Visine AR in one hour to have the same effect. Sure, you wouldn't need total colonic cleansing for practical joke purposes, but think about this -- the dose used to relieve occasional constipation is 5.5%, and you are supposed to drink 8 oz of that, and it can take 2 to 4 days for it to cause you to go poopies.

Plus, to confound things, Visine AR also contains tetrahydrozoline hydrochloride, which is an adrenergic agonist. That means that it increases the activity of the sympathetic nervous system, the branch of your autonomic nervous system responsible for the "Fight or Flight" response. The sympathetic NS actually slows down the movement of the digestive tract and increases the tone of the internal anal sphincter. I mean, think about it: would you really want to be crapping all over the place if you were running from a bear?

So there you have it. Another beautiful urban legend that falters in the face of medicine. I'll ask some of my friends on internal medicine what would serve the purpose, though, and I'll get back to you...

Posted by: e lo at September 4, 2003 01:13 PM

so if i drank some visine with a laxative to better aid my poopage, it could cause a panic attack?

Posted by: lw at September 4, 2003 06:40 PM

Better yet, if I used enough in my eyes, would I shoot diarrhea out of them or get cool explosive eye crunchies?

If it did that would make science so much cooler.

Posted by: smuve at September 5, 2003 09:37 AM