What is the recommended treatment for a vaginal Candida glabrata infection, including options for fluconazole‑resistant strains?

Treatment of Candida glabrata Vaginal Infection

For Candida glabrata vulvovaginitis, use intravaginal boric acid 600 mg daily for 14 days as first-line therapy, particularly when azole drugs have failed or when fluconazole resistance is suspected. 1, 2

Diagnostic Confirmation Before Treatment

Before initiating therapy, confirm the diagnosis through:

• Wet-mount preparation using 10% potassium hydroxide to visualize yeast (note: C. glabrata does NOT form pseudohyphae or hyphae, making microscopic identification difficult) 1, 2
• Vaginal pH measurement (normal is 4.0–4.5) 1, 2
• Vaginal culture is essential for C. glabrata because microscopy alone cannot reliably identify this species 1, 2

First-Line Treatment: Boric Acid

Boric acid 600 mg in a gelatin capsule, administered intravaginally once daily for 14 days, achieves clinical and mycological eradication rates of approximately 70–77%. 1, 3, 4

Evidence Supporting Boric Acid

• In diabetic women with C. glabrata VVC, boric acid achieved 72.4% mycological cure versus only 33.3% with fluconazole 3
• Retrospective data show 81% clinical improvement and 77% mycological eradication in patients who had failed repeated azole therapy 4
• The IDSA guidelines give this a strong recommendation despite low-quality evidence 1

Critical Pitfall to Avoid

Do not use fluconazole monotherapy for confirmed C. glabrata infection—conventional azole therapies are significantly less effective against C. glabrata than C. albicans, with response rates <50%. 1, 2, 5, 3

Alternative Treatment Options (When Boric Acid Unavailable or Fails)

If boric acid is not available or contraindicated:

1. Nystatin intravaginal suppositories 100,000 units daily for 14 days (strong recommendation; low-quality evidence) 1, 2

2. Topical 17% flucytosine cream alone or combined with 3% amphotericin B cream daily for 14 days (weak recommendation; low-quality evidence) 1, 2

3. High-dose oral fluconazole 800 mg daily for 2–3 weeks (used in Germany when topical options are unavailable, though evidence is limited) 5, 6

4. Non-fluconazole azole drugs (topical) for 7–14 days may be attempted as initial therapy before confirming species, though they remain less effective than for C. albicans 1, 2

Treatment Duration and Monitoring

• Complete the full 14-day course regardless of symptom improvement to ensure mycological eradication 1, 2, 3
• Reevaluate only if symptoms persist or recur within 2 months after completing therapy 7, 2
• If treatment fails, obtain repeat culture to confirm species and consider resistance 7, 2

Special Considerations

Recurrent C. glabrata Infection

For maintenance therapy after achieving initial cure:

• Nystatin vaginal suppositories 100,000 units daily have been successful for long-term suppression 1
• Note that even with successful initial treatment, approximately 30–40% of patients experience recurrence after stopping maintenance therapy 8

Pregnancy

• Only topical azole therapies applied for 7 days are recommended during pregnancy; oral fluconazole should be avoided due to association with spontaneous abortion and congenital malformations 9, 7
• Boric acid is contraindicated in pregnancy 5

HIV and Immunocompromised Patients

• Treatment regimens should be identical to immunocompetent patients, with equivalent response rates expected 9, 7
• However, more prolonged therapy (7–14 days) may be necessary in patients with uncontrolled diabetes or those receiving corticosteroids 1

Important Safety Information

• Oil-based vaginal preparations may weaken latex condoms and diaphragms, risking contraceptive failure 7, 2
• Topical agents rarely cause systemic side effects but may cause local burning or irritation 9, 7
• Partner treatment is not routinely recommended because vulvovaginal candidiasis is not sexually transmitted 9, 2

Why C. glabrata Requires Different Management

C. glabrata accounts for 10–20% of recurrent vulvovaginal candidiasis cases and demonstrates intrinsic reduced susceptibility to azole antifungals at standard doses. 1, 2, 5 This species often presents with milder symptoms than C. albicans but is significantly more difficult to eradicate with conventional therapies. 5, 6 The lack of pseudohyphae formation makes microscopic diagnosis unreliable, necessitating culture confirmation. 1, 2