Introduction and hypothesis: Intra-vaginal diazepam suppositories are commonly prescribed as a treatment option for high-tone pelvic floor myalgia. This triple-blinded placebo-controlled randomized trial sought to determine if 10 mg diazepam suppositories improve resting pelvic floor electromyography (EMG) compared with placebo.
Methods: Women ≥18 years of age with hypertonic pelvic floor muscles on examination, confirmed by resting EMG ≥2.0 microvolts (μv), administered vaginal suppositories containing either diazepam or placebo for 28 consecutive nights. Outcomes included vaginal surface EMG (four measurements), the Female Sexual Function Index (FSFI), the Short Form Health Survey 12 (SF-12), four visual analog scales (VAS), the Patient Global Impression of Severity (PGI-S), and the Patient Global Impression of Improvement (PGI-I). A priori sample size calculation indicated that 7 subjects in each group could detect a 2-μv difference in resting EMG tone with 90% power.
Results: Twenty-one subjects were enrolled. The mean age was 36.1 (SD 13.9) years, mean body mass index was 28.56 (SD 9.4), and the majority (85.7%) was Caucasian. When evaluating response to therapy, no difference was seen in any of the resting vaginal EMG assessments at any time point within subjects or between groups, nor was an interaction found. Additionally, no differences were noted in any of the validated questionnaires.
Conclusions: When used nightly over 4 weeks, 10 mg of vaginal diazepam was not associated with improvement in resting EMG parameters or subjective outcomes compared with placebo. This suggests such that therapy alone may be insufficient in treating high-tone pelvic floor dysfunction.