A randomized study of the effects of gabapentin on postamputation pain.
BACKGROUND
Pain after amputation is common but difficult to treat. Therefore, the authors examined whether postoperative treatment with gabapentin could reduce postamputation stump and phantom pain.


METHODS
Forty-six patients scheduled to undergo lower limb amputation were randomly assigned to receive oral gabapentin or placebo. Treatment was started on the first postoperative day and continued for 30 days. The daily dose of gabapentin or placebo was gradually increased to 2,400 mg/day. The intensity of stump and phantom pain was recorded every day on a numeric rating scale (0-10) during the 30-day treatment period. Five interviews were performed after 7, 14, and 30 days and after 3 and 6 months.


RESULTS
Results from 41 patients were included in the data analysis. The risk of phantom pain (gabapentin vs. placebo) was 55.0% versus 52.6% (risk difference, 2.4%; 95% confidence interval, -28.9 to 33.7%; P = 0.88; 30 days) and 58.8% versus 50.0% (risk difference, 8.8%; 95% confidence interval, -23.3 to 40.9%; P = 0.59; 6 months). The median intensity of phantom pain (gabapentin vs. placebo) was 1.5 (range, 0-9.0) versus 1.2 (range, 0-6.6) (P = 0.60; 30 days) and 1.0 (range, 0-6.0) versus 0.5 (range, 0-5.0) (P = 0.77; 6 months). The median intensity of stump pain was 0.85 (range, 0-8.2) versus 1.0 (range, 0-5.4) (P = 0.68; 30 days) and 0 (range, 0-8.0) versus 0 (range, 0-5.0) (P = 0.58; 6 months).


CONCLUSIONS
Gabapentin administered in the first 30 postoperative days after amputation does not reduce the incidence or intensity of postamputation pain.
Nikolajsen
Lone
L
Danish Pain Research Center, Department of Anesthesiology, Aarhus University Hospital, Aarhus, Denmark. nikolajsen@dadlnet.dk
Finnerup
Nanna B
NB
Kramp
Steffen
S
Vimtrup
Anne-Sofie
AS
Keller
Johnny
J
Jensen
Troels S
TS
D000368:Aged; D000588:Amines / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D000671:Amputation, Surgical / Q000009:adverse effects*; D000672:Amputation Stumps / Q000503:physiopathology*; D000700:Analgesics / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D003509:Cyclohexanecarboxylic Acids / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D005260:Female; D000077206:Gabapentin; D006801:Humans; D007866:Leg; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000188:drug therapy; D017288:Pain Threshold / Q000187:drug effects; D010591:Phantom Limb / Q000188:drug therapy* / Q000503:physiopathology*; D013997:Time Factors; D005680:gamma-Aminobutyric Acid / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*
D000588:Amines; D000700:Analgesics; D003509:Cyclohexanecarboxylic Acids; D005680:gamma-Aminobutyric Acid; D000077206:Gabapentin