Papers of the Week

The incremental dose of opioids used in chronic pain management often leads to a reduced opioid analgesic effect, opioid misuse, and addiction. Central dopamine (DA) dysfunction contributes to the chronicity of pain and a decreased opioid analgesic effect. Methylphenidate (MPH/Ritalin) enhances central DA function by inhibiting DA reuptake. In this study, we used a rat model of chronic pain to examine whether combination of MPH with morphine (MOR) would improve the MOR analgesic effect under a chronic pain condition.