Effect of lumbar epidural administration of neostigmine on lower urinary tract function

Neostigmine is cholinomimetic and is used for postoperative analgesia. Its urodynamics effects on voiding function have not been elucidated.

Adult patients without bothersome voiding symptoms planned for rigid cystoscopy under local anesthesia were enrolled. They underwent multichannel urodynamics (filling cystometry and pressure-flow study) before and 30 min after lumbar epidural administration of Neostigmine (2 microg/kg).

Indications for cystoscopy were check examination for follow up of carcinoma urinary bladder (n = 3), staging for carcinoma cervix (5), and removal of ureteral stent (4). Patients' mean age was 51.9 +/- 11.7 years and international Prostatic symptom score 2.34 +/- 3.41. A trend of decreased maximum cystometric capacity (MCC) was observed after Neostigmine (413.50 +/- 142.45 ml vs. 357.00 +/- 145.62 ml; P = 0.056) without any change in end-filling pressure. Five patients developed detrusor overactivity (DO) and one had increase in its amplitude (P = 0.031). Four patients developed rhythmic rectal contractions and one had increase in its amplitude (P = 0.219). There was no difference in any of the voiding parameters. Mean Visual Analog Pain Score (VAS scale 0-10) during cystoscopy for this group was significantly lower than that in a similar group of patients who did not receive Neostigmine prior to rigid cystoscopy (1.16 +/- 0.94 vs. 4.57 +/- 1.45; P = 0.0001). The drug was well tolerated in majority of the patients.

Epidural Neostigmine is effective in providing analgesia during diagnostic rigid cystoscopy. It leads to development of DO and decrease in bladder capacity without any effect on voiding function. These findings may help clinicians to use it for transurethral procedure-related pain relief without apprehension of voiding difficulty.