Boric Acid Treatment for Candida glabrata
For Candida glabrata vulvovaginitis, topical intravaginal boric acid administered in a gelatin capsule at 600 mg daily for 14 days is the recommended treatment, especially when the infection is unresponsive to oral azoles. 1
Treatment Algorithm for C. glabrata Vulvovaginitis
First-line Treatment
- Boric acid vaginal suppositories: 600 mg daily for 14 days
Alternative Options (if boric acid fails)
- Nystatin intravaginal suppositories: 100,000 units daily for 14 days 1
- Topical 17% flucytosine cream: alone or combined with 3% amphotericin B cream daily for 14 days 1, 3
- Flucytosine cream has shown 90% success in cases that failed to respond to both boric acid and azole therapy 4
Rationale for Boric Acid as First-line Treatment
- C. glabrata is often resistant to azole antifungals, making standard fluconazole treatment ineffective
- Boric acid has demonstrated significantly higher mycological cure rates compared to oral fluconazole for C. glabrata infections 2
- The IDSA guidelines specifically recommend boric acid for C. glabrata vulvovaginitis that is unresponsive to oral azoles 1
Treatment Considerations
Duration
- Complete the full 14-day course of boric acid therapy
- No advantage has been observed in extending therapy beyond 14 days 4
Follow-up
- Improvement should be seen within 48-72 hours of starting treatment 5
- No routine follow-up is needed if symptoms resolve 5
- If symptoms persist after treatment, reevaluation with culture is necessary 5
Long-term Outcomes
- Despite good initial response (63-72% mycological cure at 15 days), relapse rates are significant
- Only about 46.6% of diabetic women with C. glabrata VVC remain cured at 3 months after boric acid therapy 6
Special Populations
Diabetic Patients
- C. glabrata is more common in diabetic women with vulvovaginal candidiasis 2
- Boric acid shows superior efficacy compared to fluconazole in this population 2
- Consider glycemic control as part of management, though studies show similar HbA1c levels in those who are cured versus those who relapse 6
Recurrent Infections
- For recurrent cases, consider maintenance therapy after initial treatment 5
- Some patients may require maintenance therapy with boric acid 7
Common Pitfalls and Caveats
- Misdiagnosis: Ensure proper diagnosis with wet mount and culture before treatment
- Premature discontinuation: Complete the full 14-day course even if symptoms improve early
- Relying on azoles: C. glabrata is often resistant to azoles, with response rates <50% 7
- Ignoring recurrence: High relapse rates necessitate follow-up for persistent or recurrent symptoms
- Overlooking mixed infections: C. glabrata may coexist with other pathogens, particularly bacterial vaginosis 7
Boric acid is generally well-tolerated with minimal local side effects reported across studies 7, 4, making it both an effective and safe option for treating C. glabrata vulvovaginitis.