Kindly reference the following link(s): 


IS IT OKAY TO TAKE MEDICAL MARIJUANA, MY DOCTOR PRESCRIBED EDIBLE OR SMOKING ONES? (website)


Taking Morphine for medical reasons? | Sheikh Assim Al Hakeem


Answer:


It is permissible to use such drugs only when certain conditions are implemented:

1- That using the drug becomes a necessity.
2- A trustworthy doctor must testify that this drug is needed and useful to the patient.
3- To use only the portion needed for treatment.
4- There is no other medicine that can be taken other than it.
5- Its harm must not exceed its benefit! Addiction is the worst harm that can be caused by it.