Dronabinol showed no significantly greater pain relief than diphenhydramine in neuropathic pain after spinal cord injury.
Summary
n=7 patients with neuropathic pain below a spinal cord injury, dronabinol vs. diphenhydramine (active control), crossover design; no significant difference in pain reduction (dronabinol: +0,20 ± 0,84 VAS; diphenhydramine: -1,80 ± 2,49; Wilcoxon p=0,102). Negative finding with a very small sample.
P
PopulationAdults with spinal cord injury and neuropathic pain below the lesion level, n=7 (of which 5 evaluable)
I
InterventionDronabinol (oral), dosage and duration not explicitly stated
OutcomeNo significant difference in pain reduction between dronabinol and diphenhydramine (Wilcoxon Z=1,63, p=0,102); mean change dronabinol: 0,20 ±0,837 vs. diphenhydramine: -1,80 ±2,490
Confidence in the evidence
Very lowLowModerateHigh
Moderate
The third of four GRADE levels, the effect estimate is probably reliable.
<h4>Objective</h4>To test the efficacy and safety of a cannabinoid, dronabinol, compared with an active control, diphenhydramine, in relieving neuropathic pain in persons with spinal cord injury.<h4>Design</h4>A randomized, controlled, double-blind, crossover pilot study.<h4>Results</h4>Seven adults with spinal cord injury and neuropathic pain below the level of injury participated. Two participants withdrew while receiving dronabinol, their first medication. For the remaining five participants, change in pain on a scale of 0-10 from baseline to the end of the maintenance phase did not differ significantly between the two medications (mean change, dronabinol: 0.20 ± 0.837, range = -1.00 to 1.00; diphenhydramine: -1.80 ± 2.490, range = -6.00 to 0; Wilcoxon Z = 1.63, P = 0.102). Similar results were found when the average of the two ratings during the maintenance phase was used (dronabinol: -0.20 ± 0.671, range = -0.50 to 1.00; diphenhydramine: -1.40 ± 1.245, range = -3.50 to -0.50; Wilcoxon Z = 1.60, P = 0.109). The most common side effects were dry mouth, constipation, fatigue, and drowsiness for both medications.<h4>Conclusions</h4>On average, dronabinol was no more effective than diphenhydramine for relieving chronic neuropathic pain below the level of injury.