Fairly straightforward scenario:
This character needs to poison himself with something fast-acting that can be found in the home, specifically an NYC apartment. He's found within 10-20 minutes of his ingestion of whatever poison, but the interim should show some signs of immediate effect. He definitely needs to survive.
Thus, I need a drug or chemical or combination thereof that is, as mentioned, fast-acting, but also fairly treatable. As in, a helpful family member will induce him to vomit.
My research has been conducted via search terms: home poisons, fast-acting poisons, alcohol poisoning, methanol, isopropyl alcohol, benzodiazepenes, sleeping pills
So far I'm considering a combination of benzodiazepenes and alcohol and have rejected methanol (too slow-acting) and isopropyl alcohol (not lethal enough). Drano is right out. Any further insight/input would be much appreciated.