Transdermal buprenorphine combined with spinal morphine and naropine for pain relief in chronic peripheral vasculopathy.

THE AIM: of this study was to evaluate the effectiveness and the safety of the association of buprenorphine transdermal delivery system (TDS) (Transtec TDS) and peridural infusion of morphine and naropine, for the control of ischemic pain in patients suffering from peripheral arteriopathy. The administration of an opioid, pure agonist, as morphine, with a partial agonist opioid, as the buprenorphine, was used. Buprenorphine has shown a higher liposolubility in supraspinal districts, while the morphine acts above all on the mu receptor subtype of the spinal cord. In this way it's possible a contemporary activation of spinal and supraspinal antinociceptive mechanisms. Furthermore, the incidence of side effects is reduced by buprenorphine, which antagonizes the central effect of morphine. In this study, 43 patients were recruited, suffering from chronic pain in Fontaine stage III-IV obstructive arteriopathy, scheduled for surgery. The patients have been divided into 2 equal groups for age, sex, pathology and intensity of pain. In the first group (TTDS), at first session, a buprenorphine patch 35 microg/h (Transtec TDS) has been applied, and after 24h, a peridural catheter with elastomeric system was positioned; 100 mL (2 mg/mL) of naropine and 2 mg of morphine, 4 mL/h in 24 h, were administered. In the second group (naropine morphine, NM), buprenorphine patch was not applied and analgesia was obtained only by using peridural catheter with elastomeric system at the same doses administered in the first group. At the daily control patients with visual analogical scale (VAS)=or>40 mm received an additional dose of morphine from 2 mg to 6+/-2 mg. VAS (0-100 mm) and the evaluation of the number of the hours of sleep were used to evaluate the analgesic effectiveness of the treatment. Side effects, opioid tolerance and abuse were always recorded. All parameters were evaluated daily for a period of 20+/-5 days. The results indicate that in group TTDS there was an improvement of pain symptomatology, also confirmed by the increased hours of sleep and the lower incidence of side effects. Instead in group NM, pain control was less effective, 18 patients needed a rescue dose of morphine, and the incidence of side effects increased.