PurposeThe aim of this study is to explore non-steroid anti-inflammation drugs (NSAIDs) potency for pelvic floor muscle pain by measuring local concentration in a rat model.Materials and MethodsWe used nine NSAIDs, including nabumetone, naproxen, ibuprofen, meloxicam, piroxicam, diclofenac potassium, etodolac, indomethacin, and sulindac, and 9 groups of female Wister rats. Each group of rats was fed with one kind of NSAID (2 mg/mL) for three consecutive days. Thereafter, one mL of blood and one gram of pelvic floor muscle were taken to measure drug pharmacokinetics, including partition coefficient, lipophilicity, elimination of half-life (T1/2) and muscle/plasma converting ratio (Css, muscle/Css, plasma).ResultsDiclofenac potassium had the lowest T1/2 and the highest mean Css, muscle/Css, plasma (1.9 hours and 0.85±0.53, respectively). The mean Css, muscle/Css, plasma of sulindac, naproxen and ibuprofen were lower than other experimental NSAIDs.ConclusionDiclofenac potassium had the highest disposition in pelvic floor muscle in a rat model. The finding implies that diclofenac potassium might be the choice for pain relief in pelvic muscle.

Our study demonstrates existence of muscle bands at the bilateral urethra. They can limit the mobility of urethra during vaginal delivery and thereby cause urethra injury. Progenitor cells are located only in the smooth muscle of the urethral circle.