Background
- Azole antifungal
- Indications include Alternaria, Blastomyces dermatitidis, Coccidioides immitis, Exophiala, Exserohilum, Fungal endocarditis, Histoplasma capsulatum, Rasamsonia
Breakpoints
| Species | ECV (μg/mL) | Breakpoints (μg/mL) | Breakpoints (mm) | ||||||
|---|---|---|---|---|---|---|---|---|---|
| S | I | SDD | R | S | I | SDD | R | ||
| Candida albicans | 0.3 | ≤0.12 | 0.25-0.5 | — | ≥1 | ≥17 | 15-16 | — | ≤14 |
| Candida glabrata | 0.25 | — | — | — | — | — | — | — | — |
| Candida krusei | 0.5 | ≤0.5 | 1 | — | ≥2 | ≥15 | 13-14 | — | ≤12 |
| Candida parapsilosis | 0.03 | ≤0.12 | 0.25-0.5 | — | ≥1 | ≥17 | 15-16 | — | ≤14 |
| Candida tropicalis | 0.12 | ≤0.12 | 0.25-0.5 | — | ≥1 | ≥17 | 15-16 | — | ≤14 |
| Cryptococcus neoformans | 0.25 | ||||||||
| Cryptococcus gattii | 0.5 | ||||||||
| Aspergillus flavus | 2 | ||||||||
| Aspergillus fumigatus | 1 | ||||||||
| Aspergillus niger | 2 | ||||||||
| Aspergillus terreus | 2 | ||||||||
Therapeutic Drug Monitoring
- Measure trough within 7 days of starting, and at regular intervals or following dose adjustment
- Target trough > 1 mg/L for prophylaxis and treatment
| Trough (mcg/mL) | Recommendation |
|---|---|
| 0.0 to 0.6 | Increase dose by 100 mg and recheck trough on day 5 of new regimen |
| 0.7 to 0.9 | Increase dose by 50 mg and recheck trough on day 5 of new regimen |
| 1.0 to 4.0 | At target, no dose adjustment needed |
| 4.1 to 5.5 | Decrease dose by 50 mg and recheck trough on day 5 of new regimen |
| 5.6 to 7.9 | Hold dose. Follow daily trough levels, then restart when trough is ≤2.5 at a dose decreased by 100 mg. Recheck trough on day 5 of new regimen. |
| ≥8.0 | Hold dose. Follow daily trough levels, then restart when trough is ≤2.5 at a dose decreased by 50%. Recheck trough level on day 5 of new regimen. |
Safety
- Elevated levels predict neurotoxicity, but not hepatotoxicity
Adverse Drug Reactions
- Visual
- Floaters etc that may improve with time
- Visual hallucinations
- Colour vision loss
- Photosensitivity
- Hepatotoxicity
- QTc prolongation
Further Reading
- Voriconazole Dose Modification Guideline to Optimize Therapeutic Levels in Patients With Hematologic Malignancies. Open Forum Infect Dis. 2015;2(S1):810. doi: 10.1093/ofid/ofv133.527
