A prospective, double-blind, randomized cross-over study evaluating changes in urinary pH for relieving the symptoms of interstitial cystitis.
OBJECTIVE
To provide evidence for the clinical efficacy of changes in urinary pH on the pain associated with interstitial cystitis (IC).


METHODS
A prospective, randomized, double-blind cross-over study was conducted with 26 women with IC between 2000 and 2002, consisting of cross-over instillations of urine at physiological pH (5.0), and neutral buffered pH (NaH(2)PO(4) buffered to pH 7.5). The outcome measured was the subjective symptom of pain assessed using a visual analogue scale at baseline, after the initial instillation of solution, at washout, and after the crossover instillation. Data were analysed using repeated-measures analysis of variance.


RESULTS
There was no statistically significant difference between the mean (sd) change from baseline pain scores after instilling neutral buffered solution, at 0.50 (2.78), and acidic solution, at 0.33 (3.43) (P = 0.85). Secondary outcomes were analysed, including baseline variability and treatment-order effects; neither were significantly different between the groups.


CONCLUSIONS
There was no statistically significant difference in subjective pain scores on instilling urine at physiological pH or sodium-phosphate buffered saline in these patients with IC. Further work is required to define the role, if any, of urinary pH in the pathophysiology and treatment of IC.
Nguan
Christopher
C
Division of Urology, University of British Columbia, VGH, 2733 Heather Street, Vancouver, BC V5Z 3J5, Canada.
Franciosi
Luigi G
LG
Butterfield
Noam N
NN
Macleod
Bernard A
BA
Jens
Martha
M
Fenster
Howard N
HN
D019342:Acetic Acid / Q000008:administration & dosage; D002021:Buffers; D018592:Cross-Over Studies; D018856:Cystitis, Interstitial / Q000503:physiopathology*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D010146:Pain / Q000209:etiology; D010147:Pain Measurement; D010710:Phosphates / Q000008:administration & dosage; D011446:Prospective Studies; D014556:Urine / Q000502:physiology*
D002021:Buffers; D010710:Phosphates; D019342:Acetic Acid; C018279:sodium phosphate