MICAFUNGIN
Clinical safety rating: caution
Comprehensive clinical and safety monograph for MICAFUNGIN (MICAFUNGIN).
Inhibits the synthesis of 1,3-β-D-glucan, an essential component of the fungal cell wall, via inhibition of 1,3-β-D-glucan synthase.
| Metabolism | Primarily metabolized by the liver via the CYP450 system, specifically CYP3A4, though to a minor extent; also metabolized by arylsulfatase and catechol-O-methyltransferase. Mainly excreted unchanged in feces and bile, with minimal renal excretion. |
| Excretion | Primarily biliary/fecal (approximately 71% of administered dose recovered in feces as parent drug and metabolites), with renal excretion accounting for about 12% (mostly as metabolites, <1% unchanged). A small amount is excreted in urine. |
| Half-life | Terminal elimination half-life is approximately 10-17 hours in healthy adults. In critically ill patients, it may be prolonged (up to 20-25 hours). Half-life is dose-independent. |
| Protein binding | Highly protein bound (>99%) primarily to albumin. Saturation of binding occurs at high concentrations (>100 mcg/mL), but clinical relevance is minimal. |
| Volume of Distribution | Volume of distribution at steady state is approximately 0.29-0.39 L/kg. This indicates limited tissue distribution, primarily confined to extracellular fluid. Penetration into certain tissues (e.g., brain, eye) is poor. |
| Bioavailability | Micafungin is only administered intravenously; bioavailability by this route is 100%. Oral bioavailability is negligible (<1%) due to poor absorption. |
| Onset of Action | Intravenous: The antifungal effect begins within 30-60 minutes after infusion start, with peak concentrations achieved at the end of infusion. |
| Duration of Action | The antifungal effect persists for approximately 24 hours, supporting once-daily dosing. Clinical response is evident within 2-4 days for most indications (e.g., candidemia). |
| Molecular Weight | 1292.26 |
100 mg intravenously once daily. For esophageal candidiasis: 150 mg intravenously once daily. Loading dose not required.
| Dosage form | POWDER |
| Renal impairment | No dose adjustment required for renal impairment, including hemodialysis. |
| Liver impairment | No dose adjustment required for mild to moderate hepatic impairment (Child-Pugh A or B). Insufficient data for severe impairment (Child-Pugh C). |
| Pediatric use | For invasive candidiasis: 2 mg/kg intravenously once daily (maximum 100 mg daily). For prophylaxis: 1 mg/kg intravenously once daily (maximum 50 mg daily). |
| Geriatric use | No specific dose adjustment necessary; use standard adult dosing with renal function monitoring due to age-related decline. |
| 1st trimester | Limited human data; animal studies show fetal risk. Use only if benefit outweighs risk. |
| 2nd trimester | Limited human data; animal studies show fetal risk. Use only if benefit outweighs risk. |
| 3rd trimester | Limited human data; animal studies show fetal risk. Use only if benefit outweighs risk. |
Clinical note
Comprehensive clinical and safety monograph for MICAFUNGIN (MICAFUNGIN).
| Placental transfer | Micafungin crosses the placenta in animals; human data not available. |
| Breastfeeding | Micafungin is excreted in animal milk; no human data. Caution in breastfeeding women. |
| Lactation Rating |
■ FDA Black Box Warning
No FDA boxed warning.
| Serious Effects |
Hypersensitivity to micafungin or any component
| Precautions | Hepatic effects: elevated liver enzymes, hepatitis, hepatic impairment; monitor liver function tests, Renal effects: elevated BUN and creatinine; monitor renal function, Hypersensitivity reactions including anaphylaxis and serious skin reactions, Hematologic effects: hemolytic anemia, thrombocytopenia, Interference with other medications: potential drug interactions with immunosuppressants (e.g., sirolimus, nifedipine) |
| Food/Dietary | No significant food interactions have been reported. Micafungin is administered intravenously and its absorption is not affected by food. However, patients should maintain adequate nutrition as part of overall management of infection. |
Loading safety data…
| L3 (Moderately Safe) |
| Teratogenic Risk | Micafungin is classified as FDA Pregnancy Category C. In animal studies, embryotoxicity and teratogenicity were observed at doses below human exposure. There are no adequate and well-controlled studies in pregnant women. Use only if potential benefit justifies potential risk to the fetus. First trimester: Unknown risk; avoid unless necessary. Second and third trimesters: Limited data; consider maternal benefit vs fetal risk. |
| Fetal Monitoring | Monitor liver function tests (ALT, AST, alkaline phosphatase, bilirubin) periodically. Monitor renal function (serum creatinine, BUN). Monitor for signs of infusion-related reactions (rash, pruritus, facial swelling, vasodilation). Obtain baseline and periodic complete blood counts. Ensure patency of intravenous line during infusion. |
| Fertility Effects | In animal studies, micafungin had no adverse effects on fertility in male or female rats at doses up to 32 mg/kg/day (approximately 3 times the human AUC at the recommended dose). No human data on fertility effects. |
| Clinical Pearls | Micafungin is a broad-spectrum echinocandin that inhibits fungal (1,3)-beta-D-glucan synthase. It is active against most Candida species (including C. glabrata and C. krusei) and Aspergillus. Notably, it has no activity against Cryptococcus, Fusarium, or Mucorales. It is a preferred agent for candidemia and invasive candidiasis, especially in patients with neutropenia or recent azole exposure. Dose adjustment is not required in renal impairment, but reduce dose to 100 mg daily if moderate hepatic impairment (Child-Pugh B). Micafungin is a moderate inhibitor of CYP3A4; monitor for increased levels of sirolimus, nifedipine, and itraconazole. Avoid rapid intravenous infusion due to risk of histamine-mediated reactions. Monitor LFTs periodically as hepatocellular injury has been reported. |
| Patient Advice | This medication is given intravenously (through a vein) once daily. · Report any signs of infusion reactions such as rash, flushing, dizziness, or difficulty breathing during the infusion. · Notify your healthcare provider immediately if you experience yellowing of the skin or eyes, dark urine, or severe abdominal pain, as these may be signs of liver problems. · If you have liver disease, your doctor may adjust your dose. · Inform your doctor about all medications you take, including over-the-counter drugs and herbal supplements, as this drug may interact with sirolimus, nifedipine, or itraconazole. · There are no known food interactions, but maintain a healthy diet as recommended by your healthcare provider. |