The aim of this study was to characterize urethral neuromuscular function before and 2 weeks after medication therapy.
Premenopausal women without lower urinary tract symptoms were randomly allocated to 1 of the 6 medications for 2 weeks (pseudoephedrine ER of 120 mg, imipramine of 25 mg, cyclobenzaprine of 10 mg, tamsulosin of 0.4 mg, solifenacin of 5 mg, or placebo). At baseline and after medication, participants underwent testing: quantitative concentric needle electromyography (CNE) of the urethral sphincter using automated multimotor unit action potential software, current perception threshold (CPT) testing to measure periurethral sensation, and standard urodynamic pressure flow studies (PFS). Nonparametric tests were used to compare pre-post differences.
Fifty-six women had baseline testing, 48 (85.7%) completed follow-up CNE, and 49 (87.5%) completed follow-up CPT and PFS testing. Demographics showed no significant differences among medication groups with respect to age (mean, 34.3; SD, 10.1), body mass index (mean, 31.8; SD, 7.5), parity (median, 1; range, 0–7), or race (14% Caucasian, 80% African American). The PFS parameters were not significantly different within medication groups. No significant pre-post changes in CNE values were noted; however, trends in amplitudes were in a direction consistent with the expected physiologic effect of the medications. With CPT testing, a trend toward increased urethral sensation at the 5-Hz stimulation level was observed after treatment with pseudoephedrine (0.15–0.09 mA at 5 Hz, P = 0.03).
In women without lower urinary tract symptoms, pseudoephedrine improved urethral sensation but not urethral neuromuscular function on CNE or PFS. Imipramine, cyclobenzaprine, tamsulosin, solifenacin, and placebo did not change urethral sensation or neuromuscular function.
Pseudoephedrine may improve urethral sensation in asymptomatic women, and findings suggest that certain medication effects on the urethra are quantifiable with concentric needle electromyography.
From the *Division of Urogynecology and Pelvic Reconstructive Surgery, University of Alabama at Birmingham, Birmingham, AL; †Division of Urogynecology, Carilion Clinic, Roanoke, VA; ‡Division of Female Pelvic Medicine and Reconstructive Surgery, Northwestern University, Chicago, IL; §Department of Biostatistics and ∥Division of Gerontology, Geriatrics and Palliative Care, University of Alabama at Birmingham, Birmingham, AL.
Reprints: W. Jerod Greer, 101 Elm Avenue SE, Roanoke, VA 24013. E-mail: email@example.com.
Supported by investigator-initiated research funding to W.J.G. from Astellas and partially supported by the National Institutes of Diabetes and Digestive and Kidney Diseases (2K24-DK068389) to H.E.R.
Presented at the 32nd annual meeting of the American Urogynecologic Society, September 14–17, 2011, Providence, RI, and at the 37th annual meeting of the Society of Gynecologic Surgeons, April 11–13, 2011, San Antonio, TX.
The authors have declared they have no conflicts of interest.