Smooth muscle relaxants for intrauterine device placement: A systematic review

To systematically review evidence on whether medications with smooth muscle relaxant properties improve patient and provider outcomes for intrauterine device (IUD) placement.

We searched multiple databases through August 2022 for randomized clinical trials assessing smooth muscle relaxants for IUD placement. Primary outcomes were pain experienced with IUD placement, provider ease of placement, need for adjunctive placement measures, placement success, patient satisfaction with procedure, medication side effects occurring before clinic discharge, and adverse events occurring before clinic discharge. We extracted data from included articles, assessed risk of bias for each trial, narratively summarized results, and determined certainty of evidence for all outcomes.

Five placebo-controlled trials met inclusion criteria; four trials had low risk of bias and one had moderate risk. Two trials of topical nitroprusside gel or nitroglycerin ointment found no differences in patient pain, provider ease of placement, patient satisfaction, placement success, side effects, or adverse events. One trial suggested that drotaverine plus mefenamic acid reduced patient pain but did not improve placement success. Two trials suggested that isonicotinic acid hydrazide reduced patient pain, improved provider ease of placement and patient satisfaction, reduced need for analgesia and for cervical dilation (in one trial) and did not increase side effects; neither trial reported improved placement success.

Evidence on smooth muscle relaxants for IUD placement remains sparse with inconsistent findings across specific medications. Certainty of evidence for all outcomes was low for topical nitroprusside gel and nitroglycerin ointment, very low for drotaverine plus mefenamic acid, and mostly high for isonicotinic acid hydrazide.

Before IUD placement, healthcare providers can counsel patients on the potential for pain during placement and options for pain management. However, more evidence is needed on specific smooth muscle relaxants to determine their effectiveness as an intervention for IUD placement.