INTRASPINAL MORPHINE FOR CHRONIC PAIN - A RETROSPECTIVE, MULTICENTER STUDY

Intraspinal opioids are frequently used in the treatment of cancer and noncancer pain, but few studies have evaluated the efficacy of this t echnique. This multicenter, retrospective study surveyed physicians in the United States regarding their standard practices when using intra spinal opioids delivered via an implanted drug administration device. Thirty-five physicians (50.0%) responded, providing 429 usable patient forms (52.4%), which sought information about screening, outcomes, do sing, and adverse effects. Patients with malignant (32.7%) and noncanc er (67.3%) pain had been treated for an average of 14.6 +/- 0.57 month s (range, 8-94 months) at the time of form completion. For all patient s, the mean percent relief was 61.0% +/- 1.35%. Patients with somatic pain tended to have greater relief as measured by a global rating of p ain relief than did patients with other types of pain (Mann-Whitney te st, P = 0.0003). After titration during the first 3 months, intratheca l morphine doses increased only twofold from 6.84 +/- 0.65 mg/day at 3 months to 13.19 +/- 1.76 mg/day at 24 months. Compared to those with noncancer pain, malignant pain patients had a higher average initial d ose. The average dose used by cancer patients escalated quickly and th en stabilized, whereas the average doses used by noncancer pain patien ts exhibited a more gradual, linear increase in dose. Long-term advers e drug effects wee uncommon, but system malfunction, usually catheter related, occurred in 21.6% of patients. Prospective, randomized, contr olled clinical studies of long-term efficacy and adverse effects are w arranted.