The Analgesic Efficacy of Δ9-THC (Namisol®) in Patients With Persistent Postsurgical Abdominal Pain
Persistent postsurgical abdominal pain (PPAP) is a very difficult to treat pain. This pain can persist for months or even years and significantly diminishes quality of life. The exact underlying cause for this pain persistence is still unclear, which makes its treatment still a challenge. The promising analgesic effects of Δ9-THC in previous research, plus the improved bioavailability of Namisol® in comparison with previous Δ9-THC substances form the basis of the present research proposal.
The current study aims to investigate the analgesic efficacy of Namisol® as add-on analgesic during a long-term treatment (52 days) of persistent postsurgical abdominal pain.
|Postsurgical Pain Abdominal Pain Chronic Pain||Drug: Tetrahydrocannabinol Drug: Placebo||Phase 2|
|Study Design:||Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
|Official Title:||The Analgesic Efficacy of Δ9-THC (Namisol®) in Patients With Persistent Postsurgical Abdominal Pain; a Randomized, Double Blinded, Placebo-controlled, Experiment|
- Average VAS pain [ Time Frame: Baseline versus day 52 ]The primary outcome measure is defined as the reduction in average VAS pain scores at the end of the study (day 50-52) compared to the pre-treatment level between the Namisol® and placebo group, measured by a Visual Analoge Scale (VAS) in a pain diary.
- Electroencephalogram (EEG) [ Time Frame: Baseline versus day 52 ]Evoked potentials to noxious electrical stimuli, evoked potentials to auditory stimuli (oddball), and spontaneous brain activity will be measured in the electroencephalogram (EEG).
- Quantitative Sensory Testing (QST) [ Time Frame: Baseline versus day 15 and day 52 ]Pressure pain thresholds, electrical thresholds, electric wind-up response, and Diffuse Noxious Inhibitory Control (DNIC) will be measured using Quantitative Sensory Testing (QST).
- Depression and (pain related) anxiety [ Time Frame: Baseline versus day 52 ]Depression and (pain related) anxiety measured by questionnaires.
- Pharmacodynamic parameters [ Time Frame: Baseline versus day 15 and day 52 ]Pharmacodynamics measured by body sway and questionnaires (VASBond & Lader and VASBowdle)
- Safety parameters [ Time Frame: Baseline until follow-up (day 59-61) ]
- Electrocardiogram (ECG)
- Heart Frequency (HF) / Blood Pressure (BP)
- Adverse Events (AE)
- Quality of life [ Time Frame: Baseline versus day 52 ]Quality of life will be evaluated by questionnaires
|Study Start Date:||October 2012|
|Study Completion Date:||June 2014|
|Primary Completion Date:||June 2014 (Final data collection date for primary outcome measure)|
|Experimental: delta-9-tetrahydrocannabinol (namisol)||
The add-on treatment consists of two phases: a step-up phase (day 1-5: 3 mg TID; day 6-10: 5 mg TID), and a stable dose phase (day 11-52: 8 mg TID). The dosage may be tapered to at least 5 mg TID, when 8 mg is not tolerated.
|Placebo Comparator: Placebo||
Identical to the Namisol arm.
Please refer to this study by its ClinicalTrials.gov identifier: NCT01562483
|Radboud University Nijmegen Medical Centre|
|Nijmegen, Netherlands, 6500 HB|
|Principal Investigator:||Harry van Goor, MD, PhD||Radboud University Nijmegen Medical Centre, department of surgery|