Yeast Infection - Treatment

Boric Acid - updated: 06 April 2009

Antifungal mechanisms supporting boric acid therapy of Candida vaginitis

J Antimicrob Chemother. 2009 Feb;63(2):325-36

De Seta F, Schmidt M, Vu B, Essmann M, Larsen B.

BACKGROUND: Boric acid is a commonly cited treatment for recurrent and resistant yeast vaginitis, but data about the extent and mechanism of its antifungal activity are lacking. OBJECTIVES: The aim of this study was to use in vitro methods to understand the spectrum and mechanism of boric acid as a potential treatment for vaginal infection. METHODS: Yeast and bacterial isolates were tested by agar dilution to determine the intrinsic antimicrobial activity of boric acid. Established microbial physiology methods illuminated the mechanism of the action of boric acid against Candida albicans. RESULTS: C. albicans strains (including fluconazole-resistant strains) were inhibited at concentrations attainable intravaginally; as were bacteria. Broth dilution MICs were between 1563 and 6250 mg/L and boric acid proved fungistatic (also reflected by a decrease in CO(2) generation); prolonged culture at 50,000 mg/L was fungicidal. Several organic acids in yeast nitrogen broth yielded a lower pH than equimolar boric acid and sodium borate but were less inhibitory. Cold or anaerobic incubation protected yeast at high boric acid concentrations. Cells maintained integrity for 6 h in boric acid at 37 degrees C, but after 24 h modest intrusion of propidium iodide occurred; loss of plate count viability preceded uptake of vital stain. Growth at sub-MIC concentrations of boric acid decreased cellular ergosterol. The drug efflux pump CDR1 did not protect Candida as CDR1 expression was abrogated by boric acid. Boric acid interfered with the development of biofilm and hyphal transformation. CONCLUSIONS: Boric acid is fungistatic to fungicidal depending on concentration and temperature. Inhibition of oxidative metabolism appears to be a key antifungal mechanism

Publication Types:

• Vivo

Treatment of vulvovaginal candidiasis with boric acid powder

Am J Obstet Gynecol. 1981 Sep 15;141(2):145-8.

Van Slyke KK, Michel VP, Rein MF.

A double-blind comparison was made of the use of 14 daily intravaginal gelatin capsules containing 600 mg of boric acid powder versus the use of identical capsules containing 100,000 U nystatin diluted to volume with cornstarch for the treatment of vulvovaginal candidiasis albicans. Cure rates for boric acid were 92% at 7 to 10 days after treatment and 72% at 30 days, whereas the nystatin cure rates were 64% at 7 to 10 days and 50% at 30 days. The speed of alleviation of signs and symptoms was similar for the two drugs. There were no untoward side effects, and cervical cytologic features were not affected. In vitro studies found boric acid to be fungistatic and its effectiveness to be unrelated to pH. Blood boron analyses indicated little absorption from the vagina and a half-life of less than 12 hours. Acceptance by the patients was better than for "messy" vaginal creams, and self-made capsules containing boric acid powder are inexpensive (31 cents for fourteen) compared with the costly medication commonly prescribed.

Publication Types:

• double-blind comparison

Prolonged (3-month) mycological cure rate after boric acid suppositories in diabetic women with vulvovaginal candidiasis

J Infect. 2007 Oct;55(4):374-7.

Ray D, Goswami R, Dadhwal V, Goswami D, Banerjee U, Kochupillai N.

OBJECTIVE: Patients with diabetes mellitus (DM) are at increased risk of vulvovaginal candidiasis (VVC) due to C. glabrata. In our previous study we had shown that patients with diabetes mellitus and VVC show an overall superior mycological cure rate (74% versus 51%) with boric acid therapy at 15th day as compared to fluconazole. Present study was carried out to assess long term response to boric acid in diabetic women with VVC. MATERIAL AND METHODS: Subjects included 40 consecutive diabetic women (type 2 DM=26 and type 1 DM=14) who had achieved mycological cure (high vaginal swab culture negativity) on day 15 of therapy following single-dose oral-150 mg fluconazole (n=21) or 600 mg of boric acid suppositories given daily for 14 days (n=19). At third month of follow up, patients were assessed for signs and symptoms of VVC and a repeat HVS was collected for fungal culture. HbA1c was measured to assess glycaemic control. RESULTS: The mean age, BMI, HBA1c and frequency of various Candida species isolated at initial diagnosis were comparable in the fluconazole and boric acid treatment groups. Fifteen of 21 (71.4%) and 12 of 19 (63.1%) women who achieved mycological cure at 15 day remain cured at three months in the fluconazole and boric acid treated groups, respectively (P=0.83). With 74% mycological cure at 15th day, this would indicate that on an average only 46.6% of diabetic women with VVC would remain cured at 3 months after a course of 14 days boric acid therapy. Most of the patients relapsed with no change in Candida species. The demographic profile and mean HbA1c (8.6+/-2.2 versus 8.8+/-2.4%, P=0.83) were comparable in patients with (n=27) and without mycological cure (n=13). CONCLUSION: The results of the current study indicating comparable mycological cure rate at 3 months between fluconazole and boric acid treated patients would support use of boric acid in the acute management of VVC in view of its superior short term response in diabetic women with C. glabrata infections. However, there is need to explore other therapeutic regimens which are effective in achieving long term mycological cure in diabetic women with VVC

Publication Types:

• Randomized Controlled

Prevalence of Candida glabrata and its response to boric acid vaginal suppositories in comparison with oral fluconazole in patients with diabetes and vulvovaginal candidiasis

Diabetes Care. 2007 Feb;30(2):312-7.

Ray D, Goswami R, Banerjee U, Dadhwal V, Goswami D, Mandal P, Sreenivas V, Kochupillai N.

OBJECTIVE: A large proportion of vulvovaginal candidiasis (VVC) in diabetes is due to non-albicans Candida species such as C. glabrata and C. tropicalis. Observational studies indicate that diabetic patients with C. glabrata VVC respond poorly to azole drugs. We evaluated the response to oral fluconazole and boric acid vaginal suppositories in diabetic patients with VVC. RESEARCH DESIGN AND METHODS: A total of 112 consecutive diabetic patients with VVC were block randomized to receive either single-dose oral 150-mg fluconazole or boric acid vaginal suppositories (600 mg/day for 14 days). The primary efficacy outcome was the mycological cure in patients with C. glabrata VVC in the two treatment arms. The secondary outcomes were the mycological cure in C. albicans VVC, overall mycological cure irrespective of the type of Candida species, frequencies of yeast on direct microscopy, and clinical symptoms and signs of VVC on the 15th day of treatment. Intention-to-treat (ITT; n = 111) and per-protocol (PP; n = 99) analyses were performed. RESULTS: C. glabrata was isolated in 68 (61.3%) and C. albicans in 32 (28.8%) of 111 subjects. Patients with C. glabrata VVC showed higher mycological cure with boric acid compared with fluconazole in the ITT (21 of 33, 63.6% vs. 10 of 35, 28.6%; P = 0.01) and PP analyses (21 of 29, 72.4% vs. 10 of 30, 33.3%; P = 0.01). The secondary efficacy outcomes were not significantly different in the two treatment arms in the ITT and PP analyses. CONCLUSIONS: Diabetic women with C. glabrata VVC show higher mycological cure with boric acid vaginal suppositories given for 14 days in comparison with single-dose oral 150-mg fluconazole

Publication Types:

• Randomized Controlled Trial

Publication Types:

• Review