Pharmacokinetic and Safety Evaluation of L-tetrahydropalmatine (l-THP) With Cocaine Exposure in People With a History of Cocaine Use

Subjects will arrive the first day (Day 1) for admission and morning l-THP dosing. The l-THP will be dosed as one capsule 30 mg twice daily (matching placebo or l-THP) (total 60 mg daily). Participants will receive 7 total l-THP doses: two doses on Day 1 (morning and evening), two doses on Day 2 (morning and evening), 2 doses on Day 3 (morning and evening) and one dose the morning of Day 4 (cocaine administration day).

Subjects will arrive the first day (Day 1) for admission and morning l-THP dosing. The l-THP will be dosed as one capsule 30 mg twice daily (matching placebo or l-THP) (total 60 mg daily). Participants will receive 7 total l-THP doses: two doses on Day 1 (morning and evening), two doses on Day 2 (morning and evening), 2 doses on Day 3 (morning and evening) and one dose the morning of Day 4 (cocaine administration day).