Anidulafungin Dosing for Invasive Fungal Infections
For invasive candidiasis (including candidemia), administer anidulafungin with a 200 mg IV loading dose on day 1, followed by 100 mg IV daily thereafter. This is the standard dosing regimen endorsed by the IDSA guidelines and FDA labeling 1, 2.
Adult Dosing
Candidemia and Invasive Candidiasis
- Loading dose: 200 mg IV on Day 1
- Maintenance dose: 100 mg IV daily
- Duration: Continue for 2 weeks after documented clearance of Candida from bloodstream and resolution of clinical signs 1
This regimen is recommended as an alternative to fluconazole for empiric therapy in critically ill ICU patients, particularly those at high risk for azole-resistant species 1.
Chronic Disseminated Candidiasis
- Same dosing: 200 mg loading dose, then 100 mg daily
- Duration: Several weeks of echinocandin therapy, followed by oral fluconazole for patients unlikely to have fluconazole-resistant isolates
- Total duration: Continue until lesions resolve on repeat imaging, typically several months 1
Pediatric Dosing
For children 1 month to <18 years with invasive candidiasis, use weight-based dosing: 3 mg/kg IV loading dose on Day 1, followed by 1.5 mg/kg IV daily 2, 3.
- This achieves comparable drug exposures to adults receiving the standard 200/100 mg regimen
- Pharmacokinetic studies confirm appropriate dosing across all pediatric age groups (1 month to <2 years, 2-11 years, 12-17 years) 2, 3, 4
- Safety profile in pediatric patients is similar to adults 3
Invasive Aspergillosis
Anidulafungin is NOT recommended as first-line therapy for invasive aspergillosis. The 2008 IDSA aspergillosis guidelines list voriconazole as primary therapy, with echinocandins (including anidulafungin) noted as having "limited clinical experience" 5. While the dosing would theoretically be the same (200 mg loading, 100 mg daily), this is not an established indication.
Special Populations
No dose adjustments required for:
- Renal insufficiency (including dialysis patients) - anidulafungin has negligible renal clearance and is not dialyzable 2
- Hepatic insufficiency (any Child-Pugh class) - anidulafungin is not hepatically metabolized 2
- Geriatric patients 2
- Race or HIV status 2
ICU Patients
Pharmacokinetic studies demonstrate that critically ill ICU patients achieve similar drug exposures with standard dosing (200/100 mg) as general patient populations, requiring no dose adjustment 6.
Important Clinical Considerations
Central venous catheter removal is strongly recommended in candidemia patients, as this improves mortality 1.
Duration of therapy is critical: Premature discontinuation leads to relapse. For candidemia without metastatic complications, treat for 14 days after the first negative blood culture 1. For chronic disseminated candidiasis, continue until radiographic resolution, which typically requires months 1.
Drug interactions are minimal: Anidulafungin does not require dose adjustment when co-administered with cyclosporine, tacrolimus, voriconazole, or rifampin, as it is not metabolized by cytochrome P450 enzymes 2.
Efficacy against C. parapsilosis: Despite concerns about echinocandin activity against this species, pooled data show 77% global response rates at end of IV therapy with standard anidulafungin dosing 7.