The effect of nitroprusside on IUD insertion experience in nulliparous women: a pilot study

Concern about pain during placement of an intrauterine device (IUD) represents a barrier to use, especially among nulliparous women. We hypothesized that nitroprusside gel applied intracervically prior to IUD placement would reduce insertion-related pain.

We performed a randomized, double-blinded, placebo-controlled pilot study to evaluate the efficacy and tolerability of 10-mg nitroprusside gel (1 mL) or identical placebo gel applied intracervically in nulliparous women immediately prior to IUD placement. Subjects completed a series of 100-mm visual analogue scales at several time points. The primary outcome was subject-reported pain with IUD insertion. Secondary outcomes included provider-reported ease of insertion, subject-reported pain at other time points, side effects, adverse events and need for additional dilation.

A total of 24 women were randomized. Baseline characteristics were similar between groups. The mean pain score with IUD deployment was 73 mm (SD 17 mm) in the placebo group and 59 mm (SD 26 mm) in the nitroprusside group (p=.15). There was no difference in ease of insertion reported by providers. Two subjects required dilation, one in each group. There were two vasovagal reactions in the nitroprusside group and none in the placebo group.

Intracervical administration of 10-mg nitroprusside gel immediately prior to IUD insertion does not appear to provide a clinically relevant improvement in patient-reported pain with IUD insertion among nulliparous women.