Hydromorphone does not influence the immune response in patients affected by chronic pain

Hydromorphone (HMP) is a semisynthetic opioid that has been widely used over many years in the treatment of chronic moderatesevere pain. A number of studies have demonstrated the use of HMP in patients with cancer pain as safe and affective, and more recently HMP has been also utilised in the treatment of chronic degenerative pain (CDP). Then, some opioids are able to influence several immune parameters. Aim of our study was to assess HMP in patients with CDP in terms of safety and efficacy, to evaluate effects of HMP, within 2 months of observation, on cutaneous cell-mediated immunity (CCMI) as well as other basic immune parameters, and the production of interleukin-2 (IL-2) and interleukin-6 (IL-6). Results have shown that HMP does not influence CCMI nor the sieric levels of immunoglobulins or other immune parameters. Furthermore, it also has no effects on the 3rd and 4th complement fractions, on white blood cells count and T-lymphocyte subpopulations, on presence of seric autoantibodies, nor on production of IL-2 and IL-6. Therapy with HMP has not effects on the studied parameters of the immune system and does not seem to have any influence on the immune competence and immune response in patients with chronic pain.