Fast-release orodispersible tramadol as analgesia in hysterosalpingography with a metal cannula or a balloon catheter

Background: This study aimed to evaluate the potential benefit, in terms of pain relief, of the new oral fast-release orodispersible galvanic form of tramadol in women undergoing hysterosalpingography (HSG) with either a metal cannula or a balloon catheter. Methods: In a randomized, double-blind, placebo-controlled, 2 x 2 factorial-design trial, conducted at a single academic centre, 128 women were assigned into groups: (I) tramadol and a metal cannula, (II) tramadol and a balloon catheter, (III) placebo and a metal cannula or (IV) placebo and a balloon catheter. The primary end-point was pain registered by the patients on 10-cm visual analogue scales (VASs) at various times during and after the procedure. Secondary end-points included side effects and pain as assessed by the same physician during HSG. Results: The main effect of tramadol versus placebo medication (i.e. I and II versus III and IV) was a statistically significant difference (P < 0.001) in self-reported VAS of -0.91 (-1.35 to -0.47) on the absolute and -33% (-48% to -17%) on the relative scale in favour of tramadol. Likewise, there was a significant benefit for tramadol against placebo medication for physician-perceived VAS pain scores (39% relative reduction; P < 0.001). The main effect of the balloon catheter versus metal cannula (i.e. II and IV versus I and III) was a non-significant (P = 0.82) difference in patient-reported VAS of -0.05 (-0.49 to +0.39) and -2% (-21% to +17%). There were no medication-HSG device interactions and no differences in side effects. Conclusions: During and after HSG, fast-release orodispersible tramadol significantly reduces pain without increasing side effects.