REZZAYO
Clinical safety rating: caution
Comprehensive clinical and safety monograph for REZZAYO (REZZAYO).
Rezafungin is an echinocandin antifungal that inhibits the synthesis of 1,3-β-D-glucan, an essential component of the fungal cell wall, leading to osmotic instability and cell death.
| Metabolism | Rezafungin is not significantly metabolized by hepatic enzymes; it undergoes slow degradation by ubiquitous peptidases and is excreted primarily unchanged in feces. |
| Excretion | Elimination primarily via feces (approximately 60% of dose) and urine (approximately 20% of dose) as unchanged drug and metabolites. |
| Half-life | Terminal elimination half-life approximately 13.3 hours in healthy subjects; at steady state, half-life ranges from 7.3 to 13.6 hours in patients with candidemia/invasive candidiasis. |
| Protein binding | Approximately 99% bound to serum albumin and alpha-1-acid glycoprotein. |
| Volume of Distribution | Volume of distribution at steady state is approximately 48 L (0.6-0.9 L/kg for 70 kg adult), indicating extensive tissue distribution. |
| Bioavailability | Not applicable; administered only intravenously. |
| Onset of Action | Intravenous administration: therapeutic concentrations achieved within first dose; clinical response typically observed within 48-72 hours based on clinical trials. |
| Duration of Action | Dosing interval of 72 hours maintains therapeutic concentrations; duration of therapy is determined by clinical response, typically 14-28 days for invasive candidiasis. |
| Molecular Weight | 1024.1 Da |
Intravenous: 2 mg/kg once daily, with a maximum of 200 mg per dose.
| Dosage form | POWDER |
| Renal impairment | No dose adjustment required for GFR ≥15 mL/min; not recommended for GFR <15 mL/min or dialysis. |
| Liver impairment | No dose adjustment for Child-Pugh A or B; not recommended for Child-Pugh C. |
| Pediatric use | Safety and efficacy not established in pediatric patients. |
| Geriatric use | No specific dose adjustment; use with caution due to age-related renal decline. |
| 1st trimester | Limited human data; animal studies suggest risk based on fetal toxicity at high doses. Use only if benefit outweighs risk. |
| 2nd trimester | Limited human data; animal studies show fetal toxicity. Avoid unless no alternative. |
| 3rd trimester | Limited human data; potential for neonatal hepatic toxicity. Avoid near term. |
Clinical note
Comprehensive clinical and safety monograph for REZZAYO (REZZAYO).
| Placental transfer | Based on animal studies and molecular weight (approximately 1,024 Da), placental transfer is expected. No human data available. |
| Breastfeeding | Rezzayo (rezafungin) is likely excreted in human milk due to its molecular weight; however, no data exist. Use caution and consider the developmental benefits of breastfeeding versus potential infant exposure. |
■ FDA Black Box Warning
None.
| Serious Effects |
Hypersensitivity to rezafungin or any component of the formulation
| Precautions | Hypersensitivity reactions (including anaphylaxis), hepatic transaminase elevations, infusion-related reactions, and risk of photosensitivity. Monitor liver function and for signs of hypersensitivity. |
| Food/Dietary | No significant food interactions known. Grapefruit does not affect rezafungin metabolism. Avoid alcohol consumption if liver function is impaired. |
| Clinical Pearls |
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| Lactation Rating |
| L3 (Moderately Safe) |
| Teratogenic Risk | Insufficient human data in pregnant women. Animal studies show no evidence of teratogenicity at clinically relevant exposures. Risk cannot be ruled out; use only if potential benefit justifies potential risk to fetus. |
| Fetal Monitoring | Monitor for hepatotoxicity (elevated liver enzymes, bilirubin) and hypersensitivity reactions. No specific fetal monitoring required beyond routine prenatal care. |
| Fertility Effects | No studies on fertility in humans. Animal studies show no impairment of fertility at doses up to 5 times the human exposure. |
| REZZAYO (rezafungin) is a next-generation echinocandin with a long half-life (~130 hours) allowing once-weekly dosing. It demonstrates potent in vitro activity against Candida spp., including fluconazole-resistant strains, and Aspergillus spp. No dose adjustment is needed for mild to moderate hepatic impairment; avoid in severe hepatic impairment. Monitor for infusion-related reactions; pre-medication not routine. Rezafungin has minimal drug interactions via CYP inhibition/induction and is not a substrate of P-gp. Can be used in patients with renal impairment without adjustment. |
| Patient Advice | This medication is given as a once-weekly intravenous infusion; it is important to keep all appointments for your doses. · Common side effects may include nausea, diarrhea, vomiting, and headache. Contact your healthcare provider if you experience severe or persistent symptoms. · Inform your doctor immediately if you develop signs of liver problems such as yellowing of skin or eyes, dark urine, or abdominal pain. · Tell your doctor about all medications you are taking, including over-the-counter drugs and supplements, as interactions are rare but possible. · This drug is used to treat fungal infections; do not miss doses as it may worsen the infection. If you miss a scheduled dose, contact your healthcare provider as soon as possible. |