Nalbuphine ER Effects of Liver Disease on Pharmacokinetics and Itch

Cohort 1: 6-8 subjects will receive 1 dose of 27mg and observed for 4 days. Cohort 2: 6-7 subjects will receive 1 dose of 54 mg and observed for 4 days. Cohort 3: 6-7 subjects will receive 1 dose of 108 mg and observed for 4 days. Cohort 4: 6-8 subjects will receive 1 dose of 162 mg and observed for 4 days. Cohort 5: 6-8 healthy subjects will receive dosing of NAL ER and observed for 4 days.

Cohort 6: • 6-8 subjects with mild hepatic impairment and 6-8 subjects with moderate hepatic impairment. Doses will be subsequently escalated for each subject starting at 27 mg on Day 1 to twice daily, 12 hours apart, 27 mg, 54 mg, 108 mg, and 162 mg over 13 days.