Uniformed Services University of the Health Sciences (Dr. Arnold); Naval Hospital Jacksonville, Fla (Drs. Hayes and Sullivan) michael.arnold@usuhs.edu
The authors reported no potential conflicts of interest relevant to this article.
The views expressed in this article are those of the authors and do not necessarily reflect the official policy or position of the Department of the Navy, Department of Defense, or the United States government.
Constipation in advanced cancer is often related to opioid therapy, although bowel obstruction must be considered. Opioid-induced constipation affects 40% to 90% of patients on long-term treatment,44 and 5 days of opioid treatment nearly doubles gastrointestinal transit time.45 Opioid-induced constipation can be treated by adding a stimulating laxative followed by a peripheral acting μ-opioid receptor antagonist, such as subcutaneous methylnaltrexone or oral naloxegol.46 These medications are contraindicated if ileus or bowel obstruction is suspected.46
Nausea and vomiting are common in advanced cancer and have numerous causes. Approximately half of reversible causes are medication adverse effects from either chemotherapy or pain medication.47 Opioid rotation may improve symptoms.47 A suspected bowel obstruction should be evaluated by specialists; surgery, palliative chemotherapy, radiation therapy, or stenting may be required. Oncologists can best manage adverse effects of chemotherapy. For nausea and vomiting unrelated to chemotherapy, consider treating constipation and pain. Medication can also be helpful; a systemic review suggests metoclopramide works best, with some evidence supporting other dopaminergic agonists, including haloperidol.47
Fatigue. Both methylphenidate and modafinil have been studied to treat cancer-related fatigue.48 A majority of patients treated with methylphenidate reported less cancer-related fatigue at 4 weeks and wished to continue treatment.49 Modafinil demonstrated minimal improvement in fatigue.50 Sleep disorders, often due to anxiety or sleep apnea, may be a correctable cause.
Later symptoms
Delirium occurs in up to 90% of cancer patients near the end of life, and can signal death.51 Up to half of the delirium seen in palliative care is reversible.51 Reversible causes include uncontrolled pain, medication adverse effects, and urinary and fecal retention (TABLE 348,51). Addressing these factors reduces delirium, based on studies in postoperative patients.52 Consider opioid rotation if neurotoxicity is suspected.51
Although cancer patients are more likely than other terminal patients to have end-of- life discussions, fewer than 40% ever do.
Delirium can be accompanied by agitation or decreased responsiveness.53 Agitated delirium commonly presents with moaning, facial grimacing, and purposeless repetitive movements, such as plucking bedsheets or removing clothes.51 Delirious patients without agitation have reported, following recovery, distress similar to that experienced by agitated patients.54 Caregivers are most likely to recognize delirium and often become upset. Educating family members about the frequency of delirium can lessen this distress.54
