Table 2.

Inclusion and exclusion criteria at the second registration into the study based on genotype

Inclusion criteria
• Cancer pain targeted for daily treatment with opioids, although stable regular oral nonsteroidal anti-inflammatory drugs (NSAIDs) or acetaminophen were also administered daily (both inpatients and outpatients)
• A numerical rating scale (NRS) of ≥324-26 (average over 24 h)
• Opioid treatment-naive within 30 h
• No chemotherapy, radiotherapy, or bisphosphonate treatment in the past 2 weeks
• No change in any adjuvant analgesic (if applicable) within 72 h before commencement of the study
• Provided written informed consent
Exclusion criteria
• Patients with chronic renal failure (glomerular filtration rate, 30 mL/min)
• Patients with severe hepatic (AST (aspartate aminotransferase) > 90 U/L, ALT (alanine aminotransferase) > 126 U/L (male), ALT > 69 U/L (female), total bilirubin > 2.25 mg/dL)
• Patients with respiratory failure (respiratory system dysfunction with arterial blood partial pressure of oxygen < 60 Torr during ambient air inhalation)
• Patients with planned surgical interventions or recent surgical interventions
• Patients deemed ineligible for the study by the study coordinator or a collaborative investigator (eg, neuropathic pain and predominant spontaneous pain only)