Table 2.

The effectiveness of perioperative gabapentin for chronic pain

Positive Studies
Surgery type	Patients	Most remote follow-up	Positive findings	Negative findings
Abdominal hysterectomy99	25	1 month	Gabapentin reduced incidence of pain 1 month after surgery.	Did not identify a statistically significant decrease in immediate postoperative pain
Inguinal herniorrhaphy100	30	6 months	Gabapentin reduced pain scores at 1, 3, and 6 months after surgery. The number of patients with daily activity adversely affected by pain was lower in the gabapentin group at 1 month.	The number of patients whose daily activities were adversely affected by pain was similar between groups at 3 months and 6 months
Abdominal hysterectomy101	20	6 months	Gabapentin reduced pain scores, pain impact, and incidence of pain at 1, 3, and 6 months.	Pain impact on activities of daily living was not significantly different at 6 months
Thyroidectomy102	23	6 months	Gabapentin reduced total pain score and the incidence of more intense pain at 6 months.	Nonsignificant trend toward decreased burning sensation and numbness in the gabapentin group.
Mastectomy16	50	6 months	At 6 months gabapentin reduced the incidence of burning pain.	Gabapentin did not reduce global pain severity and opioid use at 6 months.
Breast cancer surgery17**	22	3 months	Gabapentin and mexiletine each reduced the incidence of burning pain at 3 months.	Gabapentin did not reduce the incidence of chronic pain, or patients requiring analgesics at 3 months.
Breast cancer surgery103**	20	6 months	Gabapentin reduced the incidence of chronic pain and analgesic use at 3 months.	Gabapentin did not reduce the incidence of chronic pain, and analgesic use at 6 months.
Abdominal hysterectomy104	27	1 month	Gabapentin reduced the incidence of pain at 1 month.	Gabapentin did not reduce the incidence of analgesic use at 1 month.
Negative Studies
Surgery type	Patients*	Most remote follow-up	Positive findings	Negative findings
Coronary artery bypass graft surgery18	20	3 months	Gabapentin reduced pain intensity immediately after surgery	Gabapentin did not reduce pain intensity at 1 month and 3 months.
Total hip arthroplasty19	28	6 months	None	Gabapentin did not reduce pain at any time point (one third of patients lost to remote follow-up).
Cesarean delivery20	16	3 months	Gabapentin improved acute but not chronic pain.	Gabapentin failed to reduce persistent pain, or median pain scores at 3 months.
Lower limb amputation21	15	6 months	None	Gabapentin failed to reduce the incidence and intensity of pain at 6 months.

^*Indicates the number of gabapentin patients per group available for most remote follow-up.

^**Modified radical mastectomy or lumpectomy with axillary lymph node dissection.