UC Davis

Objective

To evaluate if gabapentin 600 mg reduces pain after osmotic dilator placement the day before a dilation and evacuation (D&E) procedure.

Study design

We conducted a double-blind, placebo-controlled, randomized (stratified by vaginal parity) trial among women undergoing osmotic dilator placement before D&E at 15-23 5/7 weeks gestation. Subjects received gabapentin 600 mg or placebo 30 min before dilator placement, with re-dosing 8 h later. We assessed pain after dilator placement using a numeric rating scale (NRS; scale 0-10) at 5 min, 2, 4, and 8 h, and at presentation for D&E. The primary outcome was median NRS pain score change from baseline to 8 h after dilator placement. Secondary outcomes included gabapentin-related side effects and analgesic use.

Results

Of 121 randomized women, we excluded three subjects (allergic reaction [placebo], randomization error, no NRS data), leaving 60 gabapentin and 58 placebo subjects. Of 110 (93%) women who provided 8-hour data, median pain score changes from baseline did not differ between gabapentin and placebo groups overall (2 vs. 2.5, p = 0.52), in vaginally nulliparous women (2 vs. 4, p = 0.10) or in parous women (2 vs. 1.5, p = 0.37). We found no statistically significant differences in median pain score change from baseline to any timepoint overall or when stratified by parity. Beginning at 2 h after dilator placement, more gabapentin than placebo users experienced dizziness (29/53[55%] vs. 11/53[21%], p = 0.001) and tiredness (34/54[63%] vs. 17/54[31%], p = 0.002). The proportion of women using narcotics did not differ between gabapentin (35/60[58%]) or placebo (40/58[69%]) users (p = 0.26).

Conclusions

Gabapentin does not reduce pain with overnight osmotic dilator placement prior to D&E and causes drug-related side effects.

Implications statement

Women experience pain, mostly mild to moderate, with overnight cervical dilator placement at 15-23 5/7 weeks gestation. About 2/3 of women will use a limited quantity of narcotics if provided. Gabapentin does not decrease the pain with or following dilator placement and does not decrease narcotic use.