Gabapentin attenuates late but not acute pain after abdominal hysterectomy

Gabapentin has been suggested to decrease acute postoperative pain. We evaluated the effect of gabapentin on pain after abdominal hysterectomy.

Sixty patients scheduled for abdominal hysterectomy were randomized to receive orally gabapentin 400 mg 6 hourly or placebo. Treatment started 18 h preoperatively and continued for 5 postoperative days. Pain (visual analogue score) and consumption of morphine for 48 h and of oral paracetamol/codeine were recorded after 2, 4, 8, 24 and 48 h and on days 3-5 postoperatively. After 1 month, patients were interviewed by phone for pain, and analgesic intake after hospital discharge.

Morphine consumption (mean +/- SD) was 35 +/- 15.7 mg in the control and 28 +/- 12.1 mg in the gabapentin group (P = 0.21). Median number (range) of paracetamol 500 mg/codeine 30 mg tablets taken during days 3-5 was 1.0 (0-6) in the control and 2.0 (0-9) in the gabapentin group (P = 0.35). The visual analogue scores at rest and after cough did not differ between the two groups (F = 0.92, df = 1, P = 0.34 and F = 0.56, df = 1, P = 0.46, respectively). One month after surgery, 22/27 (81%) of the control group and 9/25 (36%) of the gabapentin group reported pain in the surgical area (chi(2) = 11.15, P = 0.002), while 11/27 (41%) of controls and 7/25 (28%) of gabapentin patients consumed analgesics for pain (chi(2) = 0.93, P = 0.39). The intensity of pain was decreased in the gabapentin group (chi(2) = 12.6, P = 0.003).

Gabapentin has no effect on immediate pain after abdominal hysterectomy but decreases pain 1 month postoperatively.