Continuous Intrathecal Infusion of Ziconotide for Treatment of Chronic Malignant and Nonmalignant Pain Over 12 Months: A Prospective, Open-label Study.

Objectives. This study aims to assess the safety and efficacy of long-term intrathecal (IT) ziconotide infusion. Materials and Methods. In this prospective study, 155 patients with severe chronic pain (48 with malignant pain, 107 with nonmalignant pain) who had been responsive to short-term IT ziconotide in a double-blind, placebo-controlled study received long-term, open-label IT ziconotide monotherapy. Efficacy assessments included the mean percentage change on the visual analog scale of pain intensity from baseline in the study of origin; safety was monitored by adverse event (AE) reports, periodic laboratory tests, and vital sign measurements. Results. At the last available observation, the visual analog scale of pain intensity scores had decreased by a mean of 36.9% from baseline in the short-term trial (N = 144; 95% CI: 30.1-43.7%; p < 0.0001). The mean IT ziconotide dose remained stable over 12 months in the 31 patients who participated in the study for ≥ one year. Ziconotide-related AEs were reported in 147 out of 155 patients (94.8%); 39.4% of patients discontinued treatment because of AEs, the majority of which were considered ziconotide related. Conclusions. Ziconotide IT monotherapy provided patients with analgesia for 12 months in this open-label study, with an acceptable benefit/risk profile and no evidence of tolerance.

A Prospective, Open-label Study of Long-term Intrathecal Ziconotide for Chronic Nonmalignant Back Pain: A Case Report.

Ziconotide is an N-type calcium channel (NCC) blocking conopeptide, acting primarily at the NCC-rich dorsal horn. Reported here is an early experience with intrathecal ziconotide in a 55-year-old man with chronic pain resulting from failed back surgery. All conservative and surgical treatments, in addition to IT morphine, failed prior to enrollment in a short-term, placebo-controlled trial testing ziconotide efficacy and safety. Following successful short-term treatment, the patient was enrolled in a long-term follow-up study. The dosing regimen, onset and resolution of adverse events, and improvement on the primary efficacy measure, the Visual Analog Scale of Pain Intensity, are discussed. Overall, the patient responded positively to ziconotide.