MICAFUNGIN SODIUM
Clinical safety rating: caution
Comprehensive clinical and safety monograph for MICAFUNGIN SODIUM (MICAFUNGIN SODIUM).
Micafungin inhibits 1,3-beta-D-glucan synthase, an enzyme required for synthesis of 1,3-beta-D-glucan, a key component of fungal cell walls.
| Metabolism | Micafungin is metabolized by arylsulfatase and catechol-O-methyltransferase, with minor involvement of CYP3A4. It is not a substrate for P-glycoprotein. |
| Excretion | Primarily hepatic metabolism; 71% recovered in feces (40% as parent drug, 31% as metabolite) and 11% in urine (1% as parent drug). |
| Half-life | Terminal elimination half-life: 11–17 hours (mean ~14 hours) in healthy adults; prolonged in moderate-to-severe hepatic impairment (up to 20–30 hours). |
| Protein binding | 99.8% bound primarily to albumin; binding is independent of concentration. |
| Volume of Distribution | Volume of distribution: 0.23–0.29 L/kg (range 0.2–0.3 L/kg); indicates limited extravascular distribution, primarily in plasma and interstitial fluid. |
| Bioavailability | Only available as intravenous formulation; oral bioavailability is negligible (<5%) and not clinically used. |
| Onset of Action | Intravenous administration: onset of antifungal activity within 1–2 hours following first dose; steady-state achieved by day 4–5. |
| Duration of Action | Duration of antifungal effect persists for approximately 24 hours, supporting once-daily dosing; clinical effect maintained throughout dosing interval. |
| Molecular Weight | 1292.3 |
100 mg intravenously once daily; for invasive candidiasis, a loading dose of 200 mg intravenously once on day 1 may be considered.
| Dosage form | INJECTABLE |
| Renal impairment | No dose adjustment required for any degree of renal impairment, including hemodialysis. Not significantly removed by hemodialysis. |
| Liver impairment | No dose adjustment required for mild or moderate hepatic impairment (Child-Pugh A or B). Insufficient data for severe hepatic impairment (Child-Pugh C); use with caution. |
| Pediatric use | Neonates and infants <4 months: 10 mg/kg intravenously once daily. Children ≥4 months and adolescents: 2-4 mg/kg intravenously once daily (maximum 100 mg daily for patients weighing ≤40 kg; 100 mg daily for patients >40 kg). For invasive candidiasis, loading dose of 3-4 mg/kg intravenously once on day 1 (maximum 200 mg for >40 kg). |
| Geriatric use | No specific dose adjustment recommended. Pharmacokinetics similar to younger adults. Monitor for adverse effects. |
| 1st trimester | Insufficient human data; animal studies show no teratogenicity but embryo-fetal toxicity at high doses. Use only if benefit outweighs risk. |
| 2nd trimester | Insufficient human data; animal studies show no teratogenicity. Use only if benefit outweighs risk. |
| 3rd trimester | Insufficient human data; animal studies show no teratogenicity. Use only if benefit outweighs risk. |
Clinical note
Comprehensive clinical and safety monograph for MICAFUNGIN SODIUM (MICAFUNGIN SODIUM).
| Placental transfer | Data not available in humans; based on molecular weight (~1292 Da) and protein binding (>99%), placental transfer is likely low. |
| Breastfeeding | Excretion into human milk unknown; due to high molecular weight and protein binding, low transfer expected. Caution if used in nursing mothers. |
■ FDA Black Box Warning
No FDA black box warning.
| Serious Effects |
Hypersensitivity to micafungin or any excipientsSevere hepatic impairment (Child-Pugh class C) without evidence of benefit
| Precautions | Hepatic effects: Elevated liver enzymes and hepatic dysfunction have been reported, including rare cases of hepatic necrosis and hepatitis., Renal effects: Elevations in BUN and creatinine may occur., Hypersensitivity reactions: Anaphylaxis and other allergic reactions have been reported., Risk of hemolytic anemia and hemolysis. |
| Food/Dietary | Avoid grapefruit and grapefruit juice as they may affect drug levels. No other food interactions are clinically significant. |
Loading safety data…
| Lactation Rating |
| L3 (Limited Data - Probably Compatible) |
| Teratogenic Risk | Limited human data; animal studies show no teratogenicity at clinically relevant doses. First trimester risk cannot be fully excluded; second and third trimester use suggests no increased malformation risk. Exposure may be considered if benefit outweighs unknown risk. |
| Fetal Monitoring | Monitor maternal liver function tests (ALT, AST, bilirubin) and renal function (serum creatinine) periodically. In neonates, monitor for hepatotoxicity. No specific fetal monitoring required; standard obstetric ultrasound may be considered. |
| Fertility Effects | Animal studies show no impairment of male or female fertility at clinically relevant doses. Human data on fertility effects are lacking. |
| Clinical Pearls |
| Micafungin is an echinocandin antifungal that inhibits glucan synthase. It is approved for esophageal candidiasis, prophylaxis of Candida infections in hematopoietic stem cell transplant recipients, and treatment of candidemia and other Candida infections. It has minimal hepatic metabolism and is not a CYP substrate, thus fewer drug interactions than azoles. Dose adjustment not required for renal impairment; caution in hepatic impairment. Monitor liver enzymes due to potential hepatotoxicity. Avoid concurrent cyclosporine due to risk of elevated liver enzymes. Hypersensitivity reactions, including anaphylaxis, have been reported. Infusion-related reactions (e.g., rash, urticaria, flushing) may occur. Not effective against Cryptococcus, Fusarium, or Zygomycetes. |
| Patient Advice | This medication is given intravenously (IV) to treat or prevent fungal infections. · Report any signs of allergic reaction: rash, itching, swelling, severe dizziness, or trouble breathing. · Inform your healthcare provider about any liver problems; blood tests to monitor liver function will be done regularly. · Avoid grapefruit and grapefruit juice while on this medication. · Do not stop treatment early, even if you feel better; complete the full course as prescribed. |