Successful use of boric acid to control azole-refractory Candida vaginitis in a woman with AIDS.

Abstract

To the Editor: With the advent of azole resistance and a lack of convenient topical or oral therapy, Candida vaginitis can be a difficult problem for women with AIDS. We describe what we believe is the first such case in the literature of an AIDS patient who has achieved complete relief using boric acid vaginal suppositories. A 32-year-old woman with a long antecedent history of recurrentCandida vaginitis was found to test positive for HIV and had a CD4 count of 10/mm3. After 9 months using fluconazole, 100 mg daily, she redeveloped thrush and vulvovaginal candidiasis. A culture grew Candida krusei and Tornlopsis glabrata, both with fluconazole minimum inhibitory concentrations(MICs) of >64 µg/ml. Itraconazole did not control her symptoms. Topical nystatin controlled the thrush but only minimally improved the vulvar symptoms. Topical gentian violet provided relief but was unacceptable to the patient because it permanently stained her clothing and bathtub. We then initiated boric acid, 600-mg vaginal suppositories and 5% lanolin ointment, which provided rapid relief of symptoms within 24 hours. The therapy was well tolerated by the patient. After 10 days of continuous, twice-daily use, there was no boric acid detected in the serum. Three relapses in the subsequent 5 months have all been easily controlled with 2- to 3-day courses of boric acid. A more recent vaginal culture grew only Candida albicans, which was azole-sensitive. Available gynecologic literature has described boric acid suppositories as a beneficial therapy for non-HIV-related Candida vaginitis(1-3). In the single-blind study by Swate and Weed, they report achieving rapid symptomatic relief in 40(100%) patients using 600-mg vaginal suppositories in conjunction with 5% boric acid in lanolin ointment topically. Two of the patients (5%) relapsed within 30 days after treatment. In the double-blind randomized study by Keller-Van-Slyke et al.(3), 108 patients were treated with either nystatin or boric acid suppository therapy. The study showed boric acid to be superior, with a 92% (48/52) cure rate compared with a 64% (36/56) cure rate with nystatin. Both groups had frequent episodes of relapse, with relapse-free rates of only 72% (boric acid) and 50% (nystatin) at 30 days. Another study by Jovanovic et al.(2) showed that boric acid was superior in patients with vaginal candidiasis refractory to miconazole and clotrimazole topical therapy. Boric acid has fungistatic properties, but the exact mechanism of action is unknown. It is postulated that the fungistatic effects of boric acid may be the result of its inherent properties as a weak acid. The acid penetrates the cell wall and disrupts the cell membrane, whereas current antifungal agents bind and inhibit ergosterol synthesis. Toxicity was not a problem. We were unable to detect any vaginal absorption of boric acid; however, the possibility that denuded or ulcerated vaginal mucosa might absorb a measurable amount is a concern. Serum concentrations <200 µg/ml are considered safe(4). Our HIV-positive patient displayed a pattern of vulvovaginal candidiasis resolution that was comparable with those reported in patients who were not HIV-positive. The patient was free of vaginitis symptoms within 24 hours of treatment, boric acid was not detected in the blood, and occasional relapses were easily controlled with short courses of boric acid. We conclude that vaginal and topical boric acid is a useful alternative for azole-refractory Candida vaginitis in a woman with AIDS. It has limited side effects and is well tolerated. Further evaluation of safety and efficacy is warranted. Acknowledgments: The Chief, Bureau of Medicine and Surgery, Navy Department, Washington, DC, Clinical Investigation Program sponsored this report #84-16-1968-607, as required by HSETCINST 6000.41A. The views expressed in this article are those of the authors and do not reflect the official policy or position of the Department of the Navy, Department of Defense, or the United States Government. Y. Todd Shinohara Sybil A. Tasker Departments of Pharmacy and Internal Medicine (Infectious Disease Division) and Clinical Investigation; Naval Medical Center; San Diego, California