Use of a sustained release opioid medication such as long-acting morphine, fentanyl patches, methadone, and buprenorphine within the last  months
Use of opioid medications for cancer-related pain, including codeine and dextropropoxyphene, currently or any time within  weeks of Day , Cycle 
Use of opioid analgesics for cancer-related pain
Chronic opioid use defined as daily opioid use for more than one month prior the scheduled date of surgery.
Rapidly progressive symptomatic metastatic disease, as defined by the need for increased opioid analgesics within one month of registration for the treatment of pain attributed to a prostate cancer metastatic lesion; patients receiving opioids must receive approval from the principal investigator (PI) for eligibility
Any concurrent opioid analgesic use (baseline opioid use must be  to be eligible)
Pain due to metastatic prostate cancer requiring opioid analgesics
Contraindications to use of naltrexone (i.e., past history of opioid abuse or dependence or evidence of opioid use in the past  days; significant hepatocellular injury as evidenced by liver enzyme levels over  times normal limits).
Presence of visceral metastases (e.g. lung, liver) detectable on cross-sectional imaging or bone metastases requiring the use of opioid analgesic or focal radiation treatment at the time of study entry
Moderate or severe symptomatic metastatic disease, defined as a requirement for treatment with opioid analgesics for cancer-related pain within  days prior to registration
At Screening need for parenteral or oral opioid analgesics (eg, codeine, dextropropoxyphene)
Symptomatic metastatic disease, as defined by the need for opioid analgesics for the treatment of pain attributed to a prostate cancer metastatic lesion; patients receiving opioids must receive approval from the principal investigator (PI) for eligibility
Increasing use of daily doses of opioid analgesics within  days prior to enrollment in the study.
Currently using an opioid antagonist or partial antagonist.
No past or current use of mixed opioid agonist/opioid antagonists or other opioid antagonists
Patients must have used opioid medication(s) for pain at some time in the  weeks prior to registration; current use of opioids (at the time of registration) and/or later during the course of the study is permitted but not required
Patients who take long acting opioid medication use
Chronic sustained-release opioid use for >  weeks duration pre operation (op) (in the  days prior to surgery)
Pre-existing opioid daily use of > mg morphine sulfate equivalent for reasons not related to LAHNC.
Documented history of medication abuse/misuse (e.g. unsanctioned dose escalation, broken opioid agreement etc.)
Patient must be opioid-tolerant (greater than or equal to  mg morphine or equivalent) and on a stable dose of oral opioids for greater than or equal to  week; stable baseline opioid dosage defined as a dosage that does not fluctuate by more than % from the average dosage over one week prior to screening
Patient is thought to be at risk for misuse, abuse, addiction or overdose for schedule II controlled substance, as evidenced by the following:\r\n* An Opioid Risk Tool (ORT) score of greater/less than or equal to . \r\n* A review of the California Prescription Control Monitoring Program (PDMP) Controlled Substance Utilization Review and Evaluation System (CURES) report demonstrates multiple prescribing providers and/or multiple pharmacies in the last  days; the CURES report will also be used to verify opioid use, opioid dose, and current prescribing providers
Chronic opioid use as defined by use of more than  mg oxycodone, or equivalent, daily
Known history of chronic pain disorders and/or chronic opioid use defined as >  mg of oral (PO) morphine or equivalent used daily for at least  days prior to enrollment
Patient has a history of opioid dependence requiring rehabilitation or the use of opioid antagonists
Concomitant medication as follows:\r\n* Subjects treated with gabapentin or other anticonvulsant for neuropathic pain will be required to taper the medication and discontinue for at least  weeks prior to study initiation\r\n* Patients on antidepressant treatment for pain or depression (tricyclic antidepressants [TCAs], selective serotonin reuptake inhibitor [SSRI], serotoninnorepinephrine reuptake inhibitors [SNRIs] etc.) will be allowed to continue their medications provided they have been on a stable dose for at least  weeks before study initiation; no dose regimen changes of antidepressants will be allowed during the study period\r\n* Patients on around-the clock opioid treatment (including tramadol) will be allowed to continue their medication provided they have been on a stable dose for at least  weeks before study initiation; the maximum allowed dose of opioid will be equivalent to  mg oral morphine sulfate; patients with higher doses will be required to taper down their opioid dose to maximum mg oral morphine equivalent, and continue on stable dose for  weeks before enrollment in the study; pro re nata (PRN) short-acting opioids for painful CIPN treatment will not be allowed; patients receiving PRN short-acting opioids (with or without acetaminophen) for pain other than CIPN will be allowed up to  daily doses, with daily recording of analgesic consumption\r\n* Treatment with nonsteroidal anti-inflammatory drug (NSAIDs) will be discontinued at least  weeks before study initiation; however, low-dose aspirin (=<  mg/day) will be allowed
Has another painful condition requiring chronic use of opioid analgesic, gabapentin, or pregabalin
History of active opioid abuse within the past  months
Diagnosis of cancer related pain currently treated with first line strong oral opioid analgesics such as morphine, oxycodone, oxymorphone, hydromorphone or hydrocodone
Patients who are classified as being opioid tolerant by receiving a baseline MEDD of >=  mg
History of chronic pain and/or daily opioid use
Patients on long-acting opioid medications, or scheduled (four or more times a day for seven or more days) short-acting opioid medications within the last  days
Chronic daily opioid requirement
Opioid tolerant, taking daily doses of strong opioid pain medication in the past  week
On strong opioid intravenous continuous infusion morphine equivalent daily dose (MEDD) >=  mg/day at the time of enrollment
History of opioid abuse
Cancer patients with severe pain (i.e., >=  on NRS) already on opioid therapy for one week or longer, at least  mg of oral morphine/day,  mcg of transdermal fentanyl/hour,  mg of oxycodone/day,  mg oral hydromorphone/day,  mg oral oxymorphone/day, or an equianalgesic dose of another opioid
Participants who have used opioid-containing medications (including cough/cold medications containing codeine and/or antidiarrheals containing loperamide) in the past  weeks, or who are expected to require opioid-containing medications within the duration of the treatment period
Patients who have been on opioid therapy for the last  weeks or more
History of active opioid abuse within the past  months
History of active opioid abuse within the past  months
Chronic opioid use for over  months
Patient with rapidly escalating pain that require hospitalization or an intravenous opioid therapy
Has had benzodiazepine, opioid or opioid like therapy initiated within  hours prior to study drug administration, or is expected to receive within  hours following initiation of chemotherapy except for single doses of midazolam, temazepam or triazolam