Opioid-induced respiratory depression suspected of drug interaction in a prostate cancer patient: a case report.

BACKGROUND: Many of the drugs used for the treatment and alleviation of symptoms in cancer patients are known to inhibit or induce cytochrome P450 (CYP). Therefore, it is important to pay attention to the drug interactions of opioid analgesics that are metabolized by CYPs, because for example when using oxycodone metabolized by CYP3A4, it is possible that the effect will be attenuated or enhanced by the concomitant use of drugs that induce or inhibit CYP3A4. Aprepitant, an antiemetic drug used in many patients receiving anticancer drugs, is known as a moderate competitive inhibitor of CYP3A4. We experienced a case of respiratory depression caused by opioids, which was suspected to be caused by a drug interaction with antiemetics especially aprepitant. CASE DESCRIPTION: The patient was a 72-year-old man. He had been treated with continuous oxycodone infusion for perianal pain associated with the rectal invasion of prostate cancer. No comorbidities other than renal dysfunction were observed. Oxycodone treatment was started at 48 mg/day, and was increased to 108 mg/day, and then the pain decreased. Once the pain was controlled, chemotherapy was planned. Antiemetics (dexamethasone, palonosetron, and aprepitant) were administered before anticancer drug administration. Approximately 3 hours after antiemetics administration and before the administration of the anticancer drugs, a ward nurse noticed that oversedation and respiratory depression had occurred. When the patient was called, he immediately woke up and was able to talk normally, so the anticancer drugs were administered as scheduled. About 2 hours after the nurse noticed oversedation, the attending physician reduced the dose of oxycodone infusion to 48 mg/day. After that, his drowsiness persisted, but his respiratory condition improved. Despite reducing the dose of oxycodone to less than half, the pain remained stable at numeric rating scale (NRS) 0-1, without the use of a rescue dose. The patient was discharged from the hospital 36 days after the administration of anticancer drugs, without any problems. CONCLUSIONS: The cause of respiratory depression in this case was thought to be a combination of factors, including drug interactions between oxycodone and antiemetics, and oxycodone accumulation due to renal dysfunction.

Psychological Barriers to the Use of Opioid Analgesics for Treating Pain in Patients With Advanced Recurrent Cancer: A Multicenter Cohort Study.

Background: We aimed to gain insight into psychological barriers toward initiation of strong opioid analgesic use in patients with advanced recurrent cancer. Methods: This study included 46 patients who were prescribed with opioid analgesics for advanced recurrent cancer. The primary outcome was psychological barriers assessed using the Japanese version of the Barriers Questionnaire-II (JBQ-II). The secondary outcomes were psychological changes and pain relief one week after the induction of strong opioid analgesics. Results: The mean age of participants was 63.6 years. Furthermore, 26.1% had an Eastern Cooperative Oncology Group (ECOG) performance status of ≥3. The mean JBQ-II total score was 1.97 (95% confidence interval: 1.75-2.19). At the initiation of opioid therapy, there was no difference in the total scores between the baseline and one week later. Nevertheless, there was a significant difference in the subscale "disease progression" score (mean 2.97 vs. 2.59, difference in means 0.38, standard error 0.16, p = 0.026). Personalized Pain Goal (PPG) was achieved in about half of the participants, and a trend toward a higher score in the subscale "harmful effects" (concern about adverse events) was observed in those who did not achieve PPG. Conclusion: This study showed that patients with advanced recurrent cancer have psychological barriers to opioid induction. The relationship between the presence of psychological barriers before and after induction of opioid analgesics and the speed of pain improvement was determined. The results may provide fundamental information for prospective intervention studies to develop individualized education programs for patients with psychological barriers to opioids.Clinical Trial Registration Number UMIN000042443.

Comparison of Analgesic Efficacy and Safety of Low-Dose Transdermal Fentanyl and Oral Oxycodone in Opioid-Naïve Patients with Cancer Pain.

In Japan, a low-dose transdermal fentanyl (TDF; 0.5 mg) has been approved to address pain in opioid-naïve patients with cancer; however, efficacy and safety data are lacking. To determine the efficacy and safety of TDF, patients with opioid-naïve cancer pain prescribed TDF (0.5 mg/d) and oral oxycodone sustained-release formulation (OXY) 10 mg/d were extracted from electronic medical and nursing records. Overall, 40 and 101 subjects were analyzed in the TDF and OXY groups, respectively. Compared with baseline (median [minimum, maximum]) values, changes in the Numerical Rating Scale (NRS) score on days 1, 3, and 7 post-administration were as follows: TDF (0 [-5, 4]) and OXY (-1.0 [-8, 3]); TDF (-1.5 [-6, 3]) and OXY (-2.0 [-8, 4]); and TDF (-2.0[-6, 3]) and OXY (-3.0[-8, 5]), respectively. No significant difference was observed between the groups on days 1 and 3; however, the change in the NRS on day 7 was significantly higher in the OXY group than that in the TDF group. Regarding adverse events, nausea occurred in 12.5 and 13.9% of patients in the TDF and OXY groups, respectively, while 12.5% of TDF- and 10.9% of OXY-treated patients experienced somnolence, revealing similar occurrence in both groups. However, constipation was more common in the OXY group (TDF: 50.0%, OXY: 71.3%). No serious adverse events (e.g., respiratory depression) were observed in either group. Low-dose TDF (0.5 mg), available only in Japan, showed comparable efficacy and safety to OXY (10 mg/d) and can be a first choice for opioid-naïve patients with cancer pain.

Psychological barriers to the use of opioid analgesics for treating pain in patients with advanced recurrent cancer (BAROC): protocol for a multicentre cohort study.

INTRODUCTION: Opioid analgesics are essential for treating cancer pain. However, patients are sometimes reluctant to use them because of concerns about addiction and dependence. Rapid pain relief following opioid administration may help overcome the psychological barriers to opioid analgesic use. This study aims to determine the relationship between psychological resistance to strong opioid analgesic use and pain amelioration speed in patients with advanced recurrent cancer. METHODS AND ANALYSIS: This ongoing, multicentre, observational study enrols patients aged 20 years or older with distant metastasis or advanced recurrent cancer receiving strong opioid analgesics for cancer pain for the first time. All participants, both inpatient and outpatient, were recruited from five Japanese hospitals. We are investigating the relationship between psychological barriers at the start of treatment and pain relief during the first week of treatment in these patients. The primary outcome is the Japanese version of the Barriers Questionnaire-II score at baseline. The secondary outcomes are the relationships between psychological barriers to strong opioid analgesic use and changes in pain over time. The participants are asked to fill out an electronic patient-reported outcome daily during the first week of treatment. The sample size was determined based on the number of patients in the year prior to study commencement who used strong opioid analgesics, met the eligibility criteria and could be expected to consent to participate in the study. ETHICS AND DISSEMINATION: The study protocol was approved by the ethics committee (approval ID B200600091) of Yokohama City University on 24 August 2020. The protocol has been reviewed by the institutional review boards at the four participating study sites. The results will be published in a peer-reviewed journal and will be presented at a relevant meeting. TRIAL REGISTRATION NUMBER: UMIN000042443.

Dermatomyositis Identified During Palliative Care Management for Chemotherapy-Associated Pain: A Case Report.

Background: Skin disorders and neuropathy often occur as side effects of chemotherapy. We encountered a patient who was treated for drug-induced skin symptoms, but the symptoms did not improve, and he was eventually diagnosed as having dermatomyositis. Case presentation: A 71-year-old man underwent chemotherapy with regorafenib in February 2020 for the postoperative recurrence of sigmoid colon cancer, but treatment was discontinued after about 2 months owing to the appearance of skin symptoms, which were thought to be side effects of regorafenib. Subsequently, his symptoms further worsened, and he was hospitalized 3 weeks after the appearance of the initial skin symptoms, and a palliative care team was asked to relieve his back pain caused by the drug-induced skin symptoms. Erythema was widely observed on the lower back and limbs, and he experienced needle stick-like pain. Furthermore, the patient demonstrated difficulty in lifting both upper limbs. As acetaminophen was effective for his pain, the dose was slowly increased with careful observation. The cause of the patient's muscle weakness was unclear, and after careful discussion of the possible causes among specialists in dermatology, neurology, and rheumatoid arthritis, a diagnosis of dermatomyositis associated with the malignant tumor was made about 10 days after his admission. The patient's symptoms gradually improved with steroid pulse treatment (methylprednisolone 1 g/day for 3 days) followed by high-dose gamma globulin treatment (2.5 g/day for 5 days), and the patient was discharged 48 days after admission. Discussion: Because this patient was referred to a palliative care team for the purpose of relieving pain caused by skin symptoms associated with chemotherapy, a crucial point is the symptoms were treated as side effects of the chemotherapy from the beginning. As neuropathy can occur as a result of chemotherapy, the pain and muscle weakness could be explained at the time; however, the symptoms continued to worsen even after the chemotherapy was stopped. Because the symptoms were not typical of polymyositis/dermatomyositis, diagnosis of the patient was delayed, even though he was treated in each specialized department. Our present case indicates that paraneoplastic syndrome should always be kept in mind when treating cancer patients.

[Assessment of psychological distress in cancer outpatients treated with chemotherapy].

PURPOSE: Few studies have been conducted to elucidate the psychological distress of cancer outpatients being treated with chemotherapy. In this study, we attempted to determine the types of psychological distress endured by cancer outpatients being treated with chemotherapy. METHODS: We investigated 194 outpatients with various malignancies, including hematological, esophageal, gastric, pancreatic, colon, lung, breast, ovarian, uterine and skin cancers, using the Japanese version of the Self-Rating Depression Scale, from June through December 2010, in our hospital. RESULTS: The results of the survey questionnaire indicated suspected adjustment disorders in 84 patients(43. 3%)and major depression in 14 patients(7. 2%). Medications prescribed for psychological distress were antianxiety drugs(18 patients: 9. 3%), antidepressant drugs(2 patients: 1. 0%), and sleeping pills(50 patients: 25. 8%). CONCLUSION: Our findings may be useful for the development of management strategies for psychological distress, and we suggest that there is a need for improvement in the quality of life of cancer outpatients being treated with chemotherapy.