Time Course and Role of Morphine Dose and Concentration in Intrathecal Granuloma Formation in Dogs: A Combined Magnetic Resonance Imaging and Histopathology Investigation.

But by the end her sufferings were horrible, her abdomen badly burnt by the radiation treatment, the pain from her multiplying tumours far beyond the reach of morphine.

Morphine deadens pain by acting at nerve synapses, but it also activates glial cells, possibly worsening the drug's side effects, such as drowsiness, tolerance, worsening of pain, and addiction.