In 2010, a study Examined Pain in Sickle Cell Disease to determine if cannabis help reduced pain. Looking at morphine and cannabinoids in transgenic mice expressing human sickle hemoglobin (HbS).

BACKGROUND: Behavioral, histochemical, and morphologic approaches are used.  Characterizing pain-related behaviors and investigate underlying mechanisms in the periphery and spinal cord.

You can read the full article here => https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2913454/