Cleon
Legend
How about this?
How about the following?
Poison (Ex): A rough-skinned newt's skin and many of its internal organs are poisonous. The save DCs are Constitution-based.
Touch poison: Contact, Fortitude DC X, initial and secondary damage 1d6 Dex.
Organ poison: Ingestion, Fortitude DC X, initial and secondary damage 2d6 Dex. If the victim's Dexterity reaches 0, the victim cannot breath for 2? minutes, which may cause suffocation.
This allows Con saves to avoid death, but it's pretty bad for characters without pretty high Con. We could change it to 1-1/2 minutes.
That looks OK to me, although I'd like to lower the touch poison damage a bit (to 1d4, 1d3 Dex or maybe even less), and make the duration of the "cannot breath" a dice roll of some kind.