Current evidence also suggests the efficacy of  dimethyl sulfoxide and amitryptyline therapy .
Hydroxyzine , intravesical bacille Calmette-Guérin  , and  resiniferatoxin therapy  failed to demonstrate efficacy , but evidence was inconclusive owing to method ological limitations .
Pentosan polysulfate may be modestly beneficial for symptoms of PBS/IC .
There is insufficient evidence for other pharmacologic treatments .
BACKGROUND More than 180 different types of therapy have been used in the treatment and management of  painful bladder syndrome/interstitial cystitis ( PBS/IC ) , yet evidence from clinical trials remains inconclusive .
This study aim ed to evaluate the efficacy of pharmacologic approaches to PBS/IC , to quantify the effect size from r and omized controlled trials , and to begin to inform a clinical consensus of treatment efficacy for PBS/IC .
A randomized double-blind trial of oral L-arginine for treatment of interstitial cystitis.
PURPOSE Nitric oxide synthase activity is decreased in the urine of patients with interstitial cystitis compared to the urine of controls . In a preliminary trial oral L-arginine , the substrate for nitric oxide synthase , increased urinary nitric oxide synthase activity and improved interstitial cystitis symptoms . This r and omized , double-blind , placebo controlled study further investigates the efficacy of L-arginine treatment for interstitial cystitis . MATERIAL S AND METHODS A total of 53 interstitial cystitis patients were assigned to receive daily 1,500 mg . L-arginine or placebo orally for 3 months . Interstitial cystitis symptoms were assessed by interviews at 2 weeks , and 1 , 2 and 3 months . RESULTS The trial was completed by 21 of 27 patients in the L-arginine group and 25 of 26 in the placebo group . Using per protocol analysis 29 % ( 6 of 21 patients ) in the L-arginine group and 8 % ( 2 of 25 ) in the placebo group were clinical ly improved by the end of the trial ( p = 0.07 ) . A Likert scale showed greater global improvement in the L-arginine group ( 48 % , 10 of 21 ) compared to the placebo group ( 24 % , 6 of 25 ) at 3 months ( p = 0.05 ) with a decrease in pain intensity ( p = 0.04 ) , and tendency toward improvement in urgency ( p = 0.06 ) and frequency of pain ( p = 0.09 ) . Using an intention to treat approach to analysis there were no differences between groups . CONCLUSIONS Oral L-arginine ( 1,500 mg . daily ) may decrease pain and urgency in a subset of interstitial cystitis patients
Current evidence also suggests the efficacy of  dimethyl sulfoxide and amitryptyline therapy .
Hydroxyzine , intravesical bacille Calmette-Guérin  , and  resiniferatoxin therapy  failed to demonstrate efficacy , but evidence was inconclusive owing to method ological limitations .
Pentosan polysulfate may be modestly beneficial for symptoms of PBS/IC .
There is insufficient evidence for other pharmacologic treatments .
BACKGROUND More than 180 different types of therapy have been used in the treatment and management of  painful bladder syndrome/interstitial cystitis ( PBS/IC ) , yet evidence from clinical trials remains inconclusive .
This study aim ed to evaluate the efficacy of pharmacologic approaches to PBS/IC , to quantify the effect size from r and omized controlled trials , and to begin to inform a clinical consensus of treatment efficacy for PBS/IC .