What are the recommended micafungin (generic) dosing regimens for adults and children for treatment of candidemia, invasive candidiasis, esophageal candidiasis, and for prophylaxis in hematopoietic stem‑cell transplant or solid‑organ transplant patients, including dose adjustments for severe hepatic dysfunction and considerations for renal impairment?

Micafungin Dosing Guidelines

Adult Dosing by Indication

For invasive candidiasis and candidemia, administer micafungin 100 mg IV once daily, continuing for at least 14 days after documented bloodstream clearance and complete resolution of symptoms. 1

Candidemia and Invasive Candidiasis

• Standard dose: 100 mg IV once daily 1
• Obtain blood cultures daily or every other day until clearance is documented 1
• Perform dilated funduscopic examination within the first week to exclude endophthalmitis 1
• Remove central venous catheters when feasible, as early removal improves outcomes 1
• In critically ill or septic ICU patients, the standard 100 mg daily dose remains appropriate 1

Esophageal Candidiasis

• Dose: 150 mg IV once daily 2, 3
• Duration: 14-21 days until clinical improvement 1

Prophylaxis in Hematopoietic Stem Cell Transplant (HSCT)

• Dose: 50 mg IV once daily 1, 4
• Initiate after the last chemotherapy dose and continue until neutrophil recovery 1
• Duration typically from preparative regimen through day +30 2

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Pediatric Dosing (≥4 months of age)

For children ≥4 months with invasive candidiasis, administer micafungin 2 mg/kg IV once daily (maximum 100 mg). 1

Treatment of Invasive Candidiasis

• Standard dose: 2 mg/kg IV once daily (maximum 100 mg) 1
• Higher doses (up to 10 mg/kg) may be considered when CNS involvement is suspected due to dose-dependent CNS penetration 1
• Children >4 months have increased clearance (20 mL/h/kg) requiring weight-based dosing 5

Prophylaxis in Pediatric HSCT Recipients

• Children ≥1 year: 1 mg/kg IV once daily (maximum 50 mg) 2
• Children 3-12 months: 50 mg/m² per day 2
• Infants <3 months: 25 mg/m² per day 2
• Administer from beginning of preparative regimen until day +30 2

Prophylaxis in Pediatric AML and Recurrent Leukemia

• Dose: 1 mg/kg IV once daily for patients with profound and prolonged neutropenia (ANC <500 for ≥10 days) 2

Neonates

• Echinocandins are reserved for salvage therapy in neonates with disseminated candidiasis 1
• Amphotericin B deoxycholate 1 mg/kg daily is preferred first-line 1
• Premature neonates have markedly increased clearance (40-80 mL/h/kg) and eightfold higher free fraction, though higher doses may not be required 5

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Dose Adjustments

Hepatic Dysfunction

No dose adjustment is necessary for moderate or severe hepatic impairment. 1, 6, 7

• Micafungin undergoes minimal hepatic metabolism via arylsulfatase, COMT, and multiple CYP isoenzymes (3A4, 1A2, 2B6, 2C) but does not require adjustment 5

Renal Impairment

No dose adjustment is required for any degree of renal impairment, including patients on dialysis. 1, 6, 7

• Renal clearance is negligible and only ~1% is excreted unchanged in urine 5, 6

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Species-Specific Considerations

Candida albicans

• Excellent susceptibility with MIC ≈0.03 mg/L 1
• Echinocandin therapy achieves 81% global response versus 62% with fluconazole 1
• Microbiologic eradication rates are higher with echinocandins than fluconazole 1

Candida parapsilosis

• Higher MICs observed, but clinical trials have not demonstrated reduced efficacy 1
• Fluconazole may be preferred if susceptibility is confirmed 1

Candida glabrata and Candida krusei

• Echinocandins including micafungin are strongly preferred 1

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Step-Down Therapy

Transition to oral fluconazole 400 mg daily (≈6 mg/kg) once the patient is clinically stable, blood cultures are cleared, and the isolate is fluconazole-susceptible. 1

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Special Populations

Critically Ill and ICU Patients

• Echinocandins (including micafungin) are strongly preferred over fluconazole as first-line therapy 1
• Standard 100 mg daily dose remains appropriate even in severe sepsis 1
• Exposure may be lower in critically ill patients (including burn patients) compared to healthy volunteers, which may affect efficacy 5

Neutropenic Patients

• Echinocandins are strongly preferred for neutropenic patients with candidemia 1
• Delay ophthalmologic examination until neutrophil recovery 1
• Non-catheter sources (e.g., gastrointestinal tract) are predominant portals of entry 1

Hematology Patients

• Exposure to micafungin is lower in hematology patients compared to healthy volunteers 5

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Drug Interactions

Micafungin has minimal drug-drug interactions because it is not significantly metabolized by CYP450 enzymes; no dose adjustments are required for interacting agents. 1, 6, 3

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Critical Monitoring Requirements

• Blood cultures every 1-2 days until documented clearance 1
• Dilated funduscopic examination within the first week by an ophthalmologist when possible 1
• For persistent candidemia, obtain imaging of genitourinary tract, liver, and spleen to identify occult foci 1

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Common Pitfalls to Avoid

• Do not delay central venous catheter removal when it is the presumed source—early removal is associated with improved outcomes 1
• Do not discontinue therapy prematurely—continue for at least 14 days after clearance and symptom resolution 1
• Do not delay ophthalmologic examination beyond the first week except in neutropenic patients 1