Physiologic, endocrine, an inflammation status after 10 years of high dose opioid treatment

There is limited knowledge about the outcomes of long-term opioid therapy in non-cancer patients. Between July and October 2012, 40 patients who had been in high dose opioid therapy (over 100 mg equivalence of morphine a day) for 10 or more years were evaluated. Patients all met the California definition of intractable which is “incurable by any known means”. All had experienced multiple non-opioid therapies and all claimed constant, debilitating pain with severe insomnia prior to high dose opioid therapy. Evaluation consisted of two written questionnaires and testing for serum cortisol, pregnenolone, corticotropin (ACTH), testosterone, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP). Questions asked about improvement in 17 physiologic functions including reading, hearing, concentration, memory, driving, sleep, movement, dressing, and libido. The other questionnaire asked about depression, hopelessness, and quality of life before and during opioid treatment. All 40 patients reported sustained pain control on a stable opioid dosage and improvements in multiple physiologic functions, depression, hopelessness, and quality of life. An abnormal hormone finding was present in 13 (32.5%) and an elevated inflammatory marker (ESR, CRP) was present in 9 (22.5%). The most common endocrine abnormality was low serum pregnenolone (4; 10.0%). The high dose opioid patients studied here greatly improved many physiologic functions as well as mental outlook on depression, hopelessness, and quality of life. Endocrine abnormalities likely represent opioid suppression in most cases. The elevated inflammatory markers suggest that the underlying cause of pain is still active or there may be on-going neuroinflammation related to centralized pain.