Comparison of the Effectiveness of Amitriptyline and Gabapentin on Chronic Neuropathic Pain in Persons With Spinal Cord Injury

Profile of the study. There were 6 random assignment groups that differed only with respect to the order in which the medications were received. Twenty-two completed all 3 phases; 26 completed the gabapentin phase, 28 the amitriptyline phase, and 25 the diphenhydramine phase. Abbreviations: A, amitriptyline; D, diphenhydramine; G, gabapentin.

Means and error bars (±2 standard error) of VAS ratings of pain intensity on average during week 8 of each medication by the 22 participants who completed all 3 phases of the study (completers) within the depressive symptomatology groups.

Mean pain intensity ratings on the VAS across time for each study medication within the depressive symptomatology groups.

Mean pain intensity ratings on the NRS across time for each study medication within the depressive symptomatology groups.

Mean decrease in average pain intensity ratings on the VAS from baseline to week 8 of each medication within the depressive symptomatology groups.

Mean percent change in average pain intensity ratings on the VAS from baseline to week 8 of each medication within depressive symptomatology groups.

Mean CESD-SF scores across time for each medication within the depressive symptomatology groups.

Dropout rate across time for each medication.

Average pain intensity ratings on the VAS during amitriptyline treatment by the 22 completers and by all available ratings for amitriptyline at each time point. Sample sizes for the “All” points varied depending on dropout and early withdrawal rates.

Average pain intensity ratings on the VAS during gabapentin treatment by the 22 completers and by all available ratings for gabapentin at each time point. Sample sizes for the “All” points varied depending on dropout and early withdrawal rates.

Average pain intensity ratings on the VAS during diphenhydramine treatment by the 22 completers and by all available ratings for diphenhydramine at each time point. Sample sizes for the “All” points varied depending on dropout and early withdrawal rates.

Average pain intensity ratings on the VAS for week 8 by the order in which each medication was received according to randomly assigned group.

Frequency distribution of the number of oxycodone-acetaminophen tablets taken for breakthrough pain during week 8 for each medication within the depressive symptomatology groups.