Predictive value of intrathecal narcotic trials for long-term therapy with implantable drug administration systems in chronic non-cancer pain patients.

This study retrospectively investigated the predictive value of intrathecal narcotic trials for long-term drug utilization via implantable pumps in chronic non-cancer patients. Data were derived from 86 patients who were categorized according to the intrathecal narcotic dose that resulted in the optimal trial response. The response during the trial period and the pattern of long-term utilization of morphine was studied, as was the impact of age, gender and diagnosis. The analysis revealed that low dose responders had lower daily dose requirements at 18 months than standard dose and high dose responders. It also showed that women had lower total daily dose requirements at 18 and 24 months and that individuals over 65 years of age had lower total daily dose requirements at 18 months. A trend toward a disproportionately higher use of adjuvant drugs and narcotic substitutions was found among high dose responders, while a trend toward a disproportionately higher total daily dose was found among cervicalgia patients. The findings indicate that the responsiveness to an intrathecal narcotic during a trial, along with the diagnosis at the time of implantation, and the patient's age and gender can shed light on the long-term utilization of intrathecal analgesics in chronic non-cancer patients. This information may be used to better select patients and design trials that more closely reflect long-term drug utilization.