Intrathecal Morphine Administration Using Implantable Pump With Continuous or Programmable Flow

Cancer is frequently associated with pain. In spite of recent improvements in cancer related pain treatment, incidence of cancerous chronic pain did not decrease. Indeed, 15 to 20% of patients are still suffering from intractable pain despite an optimal symptom management.

Treatment of cancer pain is generally based on the WHO analgesic ladder according to 3 steps. Patients with advanced cancer are often treated at WHO step 3 analgesics, i.e. morphine and its derivatives, at high dosages. But increasing the dosage of opioids also leads to accentuation of their adverse events and the corresponding risks.

At this stage of the disease, in patients with failure of conventional analgesic therapy, intrathecal injection of analgesics can be decided in order to relieve pain. 2 types of pumps allow intrathecal morphine administration : continuous or programmable flow. In this study, we want to compare the quality of analgesia obtained through these 2 flows.

Inclusion criteria

• Age > or = 18 years old.
• Patient with advanced cancer.
• Patient with severe pain, i.e. a mean daily pain score > or = 5 on an numeric rating scale.
• Failure of optimal conventional analgesic therapy : either due to intolerable adverse events or to lack of efficacy, i.e. after having tried opioid rotation techniques, different way of administration, use of rapid-acting narcotics to control acute episodes of pain, use of intravenous morphine by PCA pump.
• Possibility of return home
• Dated and signed informed consent form.

Exclusion criteria

• Patient's refusal to participate in the study.
• Ongoing pregnancy.
• Ongoing systemic infection.
• Injection site infection.
• Estimated survival less than 90 days.
• Allergy or intolerance to morphine.
• Contraindication to implantation of an intrathecal catheter.
• Patient treated with a powerful CYP1A2 inhibitor, such as fluvoxamine or enoxacin.
• Intrathecal chemotherapy planned.