Hyocine-pentothal

Hyoscine-pentothal is a fictional, pain-inducing drug that appears "24". It has been exclusively used by CTU agents as part of their time-sensitive interrogation procedure.

Appearances in "24"
The drug was first used on Richard Heller, Sarah Gavin and Behrooz Araz during Day 4. It was used several times on Christopher Henderson during his interrogation on Day 5, and Tony Almeida was planning to overdose Henderson on the drug, when he overtook Tony and injected it into him, causing Almeida's death.

Jack Bauer also uses the drug on his brother Graem Bauer, who reveals his connection to the assassination of David Palmer while under the influence of the drug. Graem's father Phillip Bauer overdoses Graem on the drug as well, resulting in his death. Jack believes that he caused Graem's death by pushing too much of the drug into Graem's system.

Effects
Curtis Manning described the drug as "feeling as though every nerve ending in your body is on fire". Jack summarizes the drug to Graem as a "neural inflammatory" and that 7cc's of the drug will cause "indescribable pain", while 8cc's will probably result in cardiac arrest.

Trivia

 * It is likely that the term Hyoscine-pentothal comes from a combination of two "truth drugs" used by the CIA: hyoscine and sodium pentothal.