All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
If this plant consists of intoxicating substances, then it is effectively equivalent to wine. Ibn ‘Umar related that the Prophet said: “Every intoxicant is Khamr (wine) and every intoxicant is forbidden.” [Muslim]
Therefore, it is forbidden to consume this plant in principle. However, if one is compelled to consume it and cannot find any permissible substance to relieve the pain and is safe from greater or equal harm, then it is permissible to use it for necessity, and the permissibleness is only in proportion to the necessity.
The Standing Committee for Issuing Fataawa was asked about the permissibility of using pethidine or morphine, which have an intoxicating effect, in case of necessity or dire need. The Standing Committee replied: “If there are no permissible substances that can be used to relieve pain in the patient aside from these two substances, then they are permissible to use for pain relief when necessary, provided that their use does not lead to greater or equal harm, like becoming addicted to them.”
Allaah Knows best.