51. Prospective Association of Serum Opioid Levels and Clinical Outcomes in Patients With Cancer Pain Treated With Intrathecal Opioid Therapy.
- Author
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Brogan SE, Sindt JE, Jackman CM, White J, Wilding V, and Okifuji A
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Analgesics, Opioid administration & dosage, Constipation chemically induced, Constipation epidemiology, Female, Humans, Hydromorphone administration & dosage, Hydromorphone blood, Hydromorphone therapeutic use, Injections, Spinal, Male, Middle Aged, Neoplasms complications, Neoplasms surgery, Pain Measurement drug effects, Pain, Postoperative drug therapy, Prospective Studies, Treatment Outcome, Young Adult, Analgesics, Opioid blood, Analgesics, Opioid therapeutic use, Cancer Pain drug therapy
- Abstract
Background: Opioids remain the mainstay of cancer pain management but are associated with systemic toxicity. In refractory cancer pain, intrathecal therapy (ITT) is associated with improved pain control, reduced systemic side effects, and improved survival. It has been assumed that ITT decreases systemic serum opioid levels and their associated toxicity, but there are limited data to support this assumption. This study hypothesizes that serum opioid levels decrease with ITT. Secondary objectives include comparative measures of pain, bowel function, and other cancer-related symptoms., Methods: Fifty-one cancer patients undergoing ITT for cancer pain were recruited in a prospective observational study. Daily oral morphine equivalency (OME) dose, serum opioid levels, Brief Pain Inventory (BPI), MD Anderson Symptom Inventory (MDASI), and a constipation questionnaire were obtained at the time of implant, and 4 and 8 weeks postoperatively., Results: Average baseline daily OME was 375 mg (median, 240; interquartile range, 150-405; range, 0-3160), mean serum morphine concentration was 53.7 ng/mL (n = 17), and mean oxycodone concentration was 73.7 ng/mL (n = 20). At 4 weeks, 87.5% of patients had discontinued non-IT opioids, and 53% had undetectable (<2 ng/mL) serum opioid concentrations. At 8 weeks, 92% remained off all non-IT opioids and 59% had undetectable serum opioid levels. IT morphine doses >4.2 mg/d were invariably associated with detectable serum levels; with doses <4.2 mg, morphine was undetectable in 80% of subjects. IT hydromorphone doses >6.8 mg/d were detectable in the serum. Using linear mixed model analyses, there were statistically significant decreases in the mean "worst pain," "average pain," and MD Anderson symptom severity and interference scores at 4 and 8 weeks. This change was independent of serum opioid levels; when analyzed separately, there was no difference in the pain scores of subjects with detectable serum opioid levels compared to those with undetectable levels at 4 and 8 weeks. Constipation ranked as "quite a bit" or "very much" decreased from 58.7% to 19.2% of subjects at week 4 (P < .001) and to 37.5% at 8 weeks (P = .23). A very low complication rate was observed., Conclusions: ITT for cancer pain was associated with a marked reduction in serum opioid concentrations, with the majority of patients having undetectable serum levels. Reducing serum opioid concentrations in cancer patients may have implications with respect to restoring bowel function, improving fatigue, and promoting the integrity of antitumor immune function and warrants further study.
- Published
- 2020
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