Intrathecal Opioid Therapy for Non-Malignant Chronic Pain: A Long-Term Perspective

Many patients with intrathecal opioid pumps do adhere to the therapy for many years but there is scarce knowledge about the long-term effects of intrathecal opioid therapy (IOT) of more than three years. We sought to assess the long-term efficacy and the presence of typical side-effects and complications of IOT.

A chart review was conducted on all patients with intrathecal opioid pumps that had been treated at our institution between 1.11.1990 and 31.12.2014. Information regarding age, gender, diagnosis, age at time of implant, duration of disease, pump type in use, revision operations, and opioid doses over time was recorded. Moreover, a questionnaire was given to the patients containing the following items: pain scores on the NRS with and without IOT, pain related disability, unwanted side-effects of opioid therapy, anxiety, and depression.

Thirty-six patients (21 m/15 f, mean age 62.9 years, range 30.5-83.9 years, SD 11.0 years) were studied. Mean duration of intrathecal therapy at time of study was 11.8 years. Thirty-two patients had gas-driven pumps and four patients had programmable pumps. The mean actual dose in those patients receiving morphine sulfate was 4.6 mg/day (range 0.2-11.1 mg, SD 2.63 mg). Pain levels prior to pump implantation were 7.98 (NRS) (range 4-10, SD 1.62). Pain levels directly after pump implantation were 4.87 (range 2-7, SD 1.86) and at time of follow-up 4.44 (range 0-9, SD 2.03). The most common unwanted side-effects reported by the patients were fatigue, obstipation, urinary retention, and sexual dysfunction. There was no life-threatening complication or permanent neurological deficit.

IOT seems to be effective also for long-term application. Clinically unwanted side-effects are relatively frequent but not the limiting factor for patient satisfaction.