Isotonitazepyne (N-pyrrolidino isotonitazene) is a benzimidazole derivative with potent opioid effects, which has been sold as a designer drug over the internet.

It has since been identified by the drug checking service CanTEST, in Canberra Australia, and tentatively in New Zealand.

[1] It's in vitro potency is approximately 1000 times that of morphine.

[2] It is specifically listed as an illegal drug in the US state of Virginia.

[3] This analgesic-related article is a stub.