Patients with liver disease (documented liver function test abnormality)
Patients with renal disease (documented glomerular filtration rate < 60mL/min/1.73m2)
Patients with a baseline (pre-operative) opioid use greater than 30 mg of morphine equivalents/day.
Patients with active alcohol dependence
Patients with active illicit drug dependence
Patients < 18 years of age and >70 years of age
Patients allergic to any medication given in either arm (list medications)
Patients who have a seizure disorder

NCT02202369_exc_T1
Condition
liver disease
NCT02202369_exc_T2
Measurement
liver function test
NCT02202369_exc_T3
Value
abnormality
NCT02202369_exc_T4
Condition
renal disease
NCT02202369_exc_T5
Measurement
glomerular filtration rate
NCT02202369_exc_T6
Value
< 60mL/min/1.73m2
NCT02202369_exc_T7
Drug
opioid
NCT02202369_exc_T8
Qualifier
baseline
NCT02202369_exc_T9
Qualifier
pre-operative
NCT02202369_exc_T10
Multiplier
greater than 30 mg of morphine equivalents/day
NCT02202369_exc_T11
Condition
alcohol dependence
NCT02202369_exc_T12
Condition
illicit drug dependence
NCT02202369_exc_T13
Person
age
NCT02202369_exc_T14
Value
< 18 years
NCT02202369_exc_T15
Person
age
NCT02202369_exc_T16
Value
>70 years
NCT02202369_exc_T17
Condition
allergic
NCT02202369_exc_T18
Drug
medication
NCT02202369_exc_T19
Condition
seizure disorder