Ed50:ld50

[Toadie]

Hi all-

I was reading about psilocybin in the Erowid vaults, and it says:

"The ED50:LD50 ratio is 641 according to the NIOSH Registry of Toxic Effects; compare this with 9637 for vitamin A, 4816 for LSD, 199 for aspirin and 21 for nicotine"

 

Am I missing something or is that ratio backwards? Wouldn't that mean a user would have to kill themselves 641 times over to facilitate any psilocybin-induced effects? The way it's written, the effective dose is 641 times greater than the lethal dose, right? Am I missing something or should the ratio be LD50:ED50?

 

 

Thanks

[CharonY]

Indeed. The therapeutic index is normally given as LD50:ED50.

To nitpick: it does not necessarily that it would be 641 times the chance of getting killed (or getting killed half the time) as the the Dose:response relationship does not have to be linear (it rarely is, actually).

[Toadie]

I figured - Just wanted to illustrate my point. Thanks, in any case!