oxymorphone and Pain--Intractable

Oxymorphone's metabolism does not involve the hepatic cytochrome P450 (CYP) system. The effect of this pharmacokinetic feature of oxymorphone on opioid prescribing is unknown.. To assess the relative frequency with which oxymorphone and oxycodone (a CYP3A-metabolized opioid analgesic) were each prescribed to patients concomitantly receiving CYP3A-modifying drugs (i.e., inducers and inhibitors) to characterize opioid-prescribing patterns in patients at risk for CYP3A-related drug interactions.. We analyzed the Sentinel Distributed Database from January 1, 2013, to December 31, 2016, to identify the proportion of patients with concomitant dispensing of selected CYP3A modifiers among initiators of oxymorphone. We then repeated the analysis using oxycodone instead of oxymorphone. We conducted sensitivity analyses that varied the washout periods for each opioid to account for potential opioid switching.. In the primary analysis, the proportion of patients with concomitant incident dispensings of oxymorphone and selected CYP3A modifiers was 3.26% (95% CI = 3.09%-3.43%), and the proportion of patients with incident dispensings of oxycodone and selected CYP3A modifiers was 2.82% (95% CI = 2.79%-2.85%). The difference between proportions was 0.43% (95% CI = 0.26%-0.60%). Sensitivity analyses that varied the washout periods for each opioid with respect to the other opioid to account for switching yielded similar results.. We observed similar proportions of patients using selected CYP3A modifiers concomitantly with both oxymorphone and oxycodone. While the CIs of the point estimates did not overlap, the absolute differences between the proportions were small.. This project was supported by Task Order HHSF22301001T under Master Agreement HHSF223201400030I from the U.S. Food and Drug Administration (FDA). The FDA approved the study protocol, including the statistical analysis plan, and reviewed and approved the manuscript. Coauthors from the FDA participated in the results interpretation and in the preparation and decision to submit the manuscript for publication. Coyle, Money, Staffa, Meyer, and Woods are employed by the FDA. The other authors have no financial conflicts of interest to report. The views expressed are those of the authors and not necessarily those of the U.S. Department of Health and Human Services, U.S. Food and Drug Administration.

Topics: Adverse Drug Reaction Reporting Systems; Analgesics, Opioid; Cytochrome P-450 CYP3A Inhibitors; Drug Interactions; Humans; Oxycodone; Oxymorphone; Pain, Intractable; Practice Patterns, Physicians'; United States

To assess the safety, efficacy, and use of continuous iv infusion (CI) of opioids for cancer pain, we reviewed the clinical experience of 36 patients who received 46 CIs. CI was always preceded by a period of repetitive dosing of opioids. Morphine was used in 36 CIs, methadone in four, hydromorphone in four, oxymorphone in one, and levorphanol in one. Mean doses during CI were the morphine equivalent of 17 mg/hour (range, 0.7-100) at the start, 69 mg/hour (range, 4-480) at the maximum, and 52 mg/hour (range, 1-480) at termination. Pain relief was acceptable during 28 CIs, unacceptable during 17, and unknown during one. There were few toxic effects other than sedation. Twenty-five patients died, 12 resumed im or oral opioids, six continued CI with a different opioid (yielding analgesia in two), and outcome was undetermined in three. This review suggests that (a) CI is safe, (b) analgesia may require rapid escalation of infusion rates, (c) patient response varies and lack of acceptable analgesia may occur in up to one-third, (d) ineffective CI with one drug may be followed by success with another, (e) CI should be preceded by a period of repetitive iv boluses with the same drug, and (f) guidelines can be developed which incorporate pharmacokinetic principles.

Topics: Adolescent; Adult; Aged; Child; Child, Preschool; Drug Administration Schedule; Drug Evaluation; Humans; Hydromorphone; Infant; Infusions, Parenteral; Levorphanol; Methadone; Middle Aged; Morphine; Narcotics; Neoplasms; Oxymorphone; Pain, Intractable; Palliative Care; Retrospective Studies

Topics: Aged; Humans; Male; Morphine; Oxymorphone; Pain, Intractable; Pharyngeal Neoplasms; Suppositories