Intrathecal Drug Delivery System May Decrease Opioid Consumption in Chronic Pain

Use of an intrathecal drug delivery system (IDDS) was found to reduce opioid consumption at 1 year compared with comprehensive medical management (CMM) alone among patients with noncancer chronic pain. These findings, from a retrospective cohort study, were published in Pain Medicine.

Data for this study were sourced from the Korean National Health Insurance Service (NHIS) beginning in 2014, which is when the NHIS initiated reimbursement for placement of a programmed intrathecal pump for the management of chronic noncancer pain. Patients (N=1302) with noncancer chronic pain who were receiving treatment with morphine via IDDS implantation (n=29) or CMM alone (n=1273) for more than 6 months were propensity matched in a 1:3 ratio. The primary study endpoint was comparison of average morphine equivalent daily doses (MEDDs) at 6 and 12 months. Secondary endpoints included the number of emergency department (ED) visits, the number of hospitalizations, and medical expenditures.

The matched IDDS (n=23) and CMM (n=59) cohorts consisted of 60.9% and 59.3% men, mean age was 49.0±13.0 and 47.5±13.4 years, 1-year MEDD prior to the index date was 123.3±121.5 and 114.6±151.3 mg/d, Charlson comorbidity index score was 0 for 52.2% and 72.9%, and the number of ED visits prior to index date was 5.4±10.1 and 0.5±2.6, respectively.

At 6 months, the IDDS group had lower opioid consumption (MEDD, 81.6 vs 129.1 mg/d; P =.038) and more ED visits (mean, 0.7 vs 0.0; P <.001) compared with the CMM group. At 12 months, a greater decrease in opioid consumption was noted for the IDDS group vs the CMM group (MEDD, 53.2 vs 123.9 mg/d; P =.008); however, the number of ED visits increased for those in the IDDS group (mean, 2.3 vs 0.0; P <.0001). No group differences were observed for the number of hospitalizations or healthcare expenditures at 6 or 12 months.

At month 6 following pump implantation, opioid consumption (mean difference [MD], -41.8 mg/d; P =.007) and total healthcare expenditures (MD, -$1523.4; P =.002) decreased significantly among participants in the IDDS group. At 12 months, opioid consumption remained significantly lower than prior to implantation (MD, -48.7 mg/day; P =.007) but not healthcare costs (P =.159).

This study may have been biased by including both inpatient and outpatient opioid prescriptions, which could include surgical-based pain analgesia.

This study found that IDDS therapy was associated with decreased opioid consumption at 1 year compared with CMM alone. The authors reported, “Although opioid dose escalations were suspected to progress independently of the opioid delivery method … further studies are also encouraged to identify whether differences exist in affecting opioid tolerance according to the delivery routes ([intrathecal], intravenous, oral, or transdermal).”