The purpose of this study is to evaluate the effect of steady-state (constant concentration of medication in the blood) TMC435 (150 mg, once a day) on the steady state pharmacokinetics (what the body does to the medication) of R- and S-methadone.
This is an open label (all people know the identity of the intervention) drug-drug interaction (TMC435 versus methadone) study. Approximately 12 hepatitis C virus-negative opioid-dependent participants on stable maintenance therapy (for at least 30 days before screening) will be enrolled in the study. The study will consist of 3 phases: 1) Run-in phase: during this phase, participants will take individualized (dose of methadone will be adjusted for each participant between a range of 30 and 150 mg daily) dose of methadone from Day -14 (14 days before the first intake of TMC435) till Day -1 (1 day before the first intake of TMC435), which will be supervised by the medical staff. 2) 7 days treatment phase: during this phase, the participants will take 150 mg dose of TMC435 once daily from Day 1 to Day 7 orally (by mouth) plus the individualized dose of methadone which will be supervised by the medical staff. 3) Follow-up phase: during this phase, the participants will continue to take only the individualized dose of methadone for 30-32 days. Safety evaluations will include assessment of adverse events, clinical laboratory tests, cardiovascular safety, physical examination and alcohol breath test. The total study duration will be of 22 days excluding screening and follow-up phase.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
TREATMENT
Masking
NONE
Enrollment
13
Participants will receive 150 mg dose of TMC435 orally (by mouth) once daily for 7 days of treatment (from Day 1 to Day 7).
Participants will receive supervised individualized methadone dose (dose of methadone will be adjusted for each participant between a range of 30 and 150 mg daily \[extremes included\]) from Day -14 untill Day 8. Participants will continue to receive individualized methadone during follow up of 30 to 32 days.
Unnamed facility
Toronto, Canada
Predose plasma concentration of S-methadone
Time frame: Day -4 to Day 6
Maximum plasma concentration of S-methadone
Time frame: On Day -1 and Day 7 at 0.5, 1, 1.5, 2, 3, 4, 5, 6, 8 and 12 hours postdose
Minimum plasma concentration between 0 hour and dosing interval of S-methadone
Time frame: On Day -1 and Day 7 at 0.5, 1, 1.5, 2, 3, 4, 5, 6, 8 and 12 hours postdose
Average steady-state plasma concentration of S-methadone
Time frame: On Day -1 and Day 7 at 0.5, 1, 1.5, 2, 3, 4, 5, 6, 8 and 12 hours postdose
Time to reach the maximum plasma concentration of S-methadone
Time frame: On Day -1 and Day 7 at 0.5, 1, 1.5, 2, 3, 4, 5, 6, 8 and 12 hours postdose
Area under the curve from time of administration up to 24 hours post dosing of S-methadone
Time frame: On Day -1 and Day 7 at 0.5, 1, 1.5, 2, 3, 4, 5, 6, 8 and 12 hours postdose
Fluctuation index of S-methadone, ie, percentage fluctuation (variation between maximum and minimum concentration at steady-state)
Time frame: On Day -1 and Day 7 at 0.5, 1, 1.5, 2, 3, 4, 5, 6, 8 and 12 hours postdose
Predose plasma concentration of R-methadone
Time frame: Day -4 to Day 7
Maximum plasma concentration of R-methadone
Time frame: On Day -1 and Day 7 at 0.5, 1, 1.5, 2, 3, 4, 5, 6, 8 and 12 hours postdose
Minimum plasma concentration between 0 hour and dosing interval of R- and S-methadone
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Time frame: On Day -1 and Day 7 at 0.5, 1, 1.5, 2, 3, 4, 5, 6, 8 and 12 hours postdose
Average steady-state plasma concentration of R-methadone
Time frame: On Day -1 and Day 7 at 0.5, 1, 1.5, 2, 3, 4, 5, 6, 8 and 12 hours postdose
Time to reach the maximum plasma concentration of R-methadone
Time frame: On Day -1 and Day 7 at 0.5, 1, 1.5, 2, 3, 4, 5, 6, 8 and 12 hours postdose
Area under the curve from time of administration up to 24 hours post dosing of R-methadone
Time frame: On Day -1 and Day 7 at 0.5, 1, 1.5, 2, 3, 4, 5, 6, 8 and 12 hours postdose
Fluctuation index of R-methadone, ie, percentage fluctuation (variation between maximum and minimum concentration at steady-state)
Time frame: On Day -1 and Day 7 at 0.5, 1, 1.5, 2, 3, 4, 5, 6, 8 and 12 hours postdose
Predose plasma concentration of TMC435
Time frame: Day 4 to Day 6
Maximum plasma concentration of TMC435
Time frame: On Day 7 at 0.5, 1, 1.5, 2, 3, 4, 5, 6, 8 and 12 hours postdose and on Day 8 at 24 hour postdose
Minimum plasma concentration between 0 hour and dosing interval of TMC435
Time frame: On Day 7 at 0.5, 1, 1.5, 2, 3, 4, 5, 6, 8 and 12 hours postdose and on Day 8 at 24 hour postdose
Average steady-state plasma concentration of TMC435
Time frame: On Day 7 at 0.5, 1, 1.5, 2, 3, 4, 5, 6, 8 and 12 hours postdose and on Day 8 at 24 hour postdose
Time to reach the maximum plasma concentration of TMC435
Time frame: On Day 7 at 0.5, 1, 1.5, 2, 3, 4, 5, 6, 8 and 12 hours postdose and on Day 8 at 24 hour postdose
Area under the curve from time of administration up to 24 hours post dosing of TMC435
Time frame: On Day 7 at 0.5, 1, 1.5, 2, 3, 4, 5, 6, 8 and 12 hours postdose and on Day 8 at 24 hour postdose
Fluctuation index of TMC435, ie, percentage fluctuation (variation between maximum and minimum concentration at steady-state)
Time frame: On Day 7 at 0.5, 1, 1.5, 2, 3, 4, 5, 6, 8 and 12 hours postdose and on Day 8 at 24 hour postdose
Short Opiate Withdrawal Scale Scores
Short Opiate Withdrawal Scale is used for the assessment of opioid withdrawal. It consists of 10 items and items are designed to measure symptoms, on a scale from 0 to 3 (0= None, 1= Mild, 2= Moderate, 3= Severe). The total score ranges from 0 (best) to 30 (worst). Higher scores indicate worsening.
Time frame: On Day-1 and Day 7 at 2 hour and 4 hour predose; on Day-7, Day-2, and Day 1 to Day 6 at predose
Desires for Drugs Questionnaire
Time frame: On Day-1 and Day 7 at 2 hour and 4 hour predose; on Day-7, Day-2, and Day 1 to Day 6 at predose
Resting pupil diameter
Pupillometry will be performed and resting pupil diameter will be assessed with a validated pupillograph.
Time frame: On Day-1 and Day 7 at 2 hour and 4 hour predose; on Day-7, Day-2, and Day 1 to Day 6 at predose
Number of participants with adverse events as a measure of safety and tolerability
Time frame: Up to 30 to 32 days after the last medication dose