The drug is ibogaine. From the article:

Ibogaine is made from the bark of a shrub (Tabernanthe iboga) native to Central Africa, where it is used for ceremonial purposes. Researchers have tended to shy away from exploring the use of ibogaine for the treatment of conditions other than opioid dependence and withdrawal2, because it is tightly regulated in many countries and can cause fatal heartbeat irregularities,