A randomized double-blind trial of oral L-arginine for treatment of interstitial cystitis.

Abstract

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 randomized, double-blind, placebo controlled study further investigates the efficacy of L-arginine treatment for interstitial cystitis.

MATERIALS 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 clinically 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.

• Authors: G E Korting, S D Smith, M A Wheeler, R M Weiss, H E Foster Jr
• Journal: The Journal of urology (J Urol) Vol. 161 Issue 2 Pg. 558-65 (Feb 1999) ISSN: 0022-5347 [Print] United States
• PMID: 9915448 (Publication Type: Clinical Trial, Journal Article, Randomized Controlled Trial, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Arginine

Topics

• Administration, Oral
• Arginine (administration & dosage)
• Cystitis, Interstitial (drug therapy)
• Double-Blind Method
• Female
• Follow-Up Studies
• Humans
• Middle Aged
• Surveys and Questionnaires