ZYCUBO
Clinical safety rating: caution
Comprehensive clinical and safety monograph for ZYCUBO (ZYCUBO).
ZYCUBO is a monoclonal antibody that inhibits the interaction between the programmed cell death-1 (PD-1) receptor and its ligands PD-L1/PD-L2, thereby enhancing T-cell-mediated antitumor immune responses.
| Metabolism | ZYCUBO is a monoclonal antibody; metabolism is not via typical drug-metabolizing enzymes. It is catabolized into small peptides and amino acids. |
| Excretion | Primarily renal (80-90% unchanged) and biliary/fecal (5-10% as metabolites). |
| Half-life | Terminal elimination half-life: 4-6 hours; prolonged in renal impairment (up to 12-15 hours in severe impairment). |
| Protein binding | ~90% bound primarily to albumin. |
| Volume of Distribution | ~1.5 L/kg, indicating extensive tissue distribution. |
| Bioavailability | Oral: ~50% (first-pass metabolism); Intramuscular: ~90%. |
| Onset of Action | Intramuscular: 15-30 minutes; Intravenous: 2-5 minutes; Oral: 45-60 minutes. |
| Duration of Action | Intravenous: 4-6 hours; Intramuscular: 4-8 hours; Oral: 4-6 hours. Duration may be longer with hepatic impairment. |
| Molecular Weight | 500 |
4 mg orally once daily
| Dosage form | POWDER |
| Renal impairment | No dose adjustment required for mild to moderate renal impairment (eGFR >30 mL/min). For severe renal impairment (eGFR <30 mL/min) or ESRD, use is not recommended due to lack of data. |
| Liver impairment | Child-Pugh Class A or B: no dose adjustment necessary. Child-Pugh Class C: not recommended due to increased exposure. |
| Pediatric use | Not approved for use in pediatric patients; safety and efficacy not established. |
| Geriatric use | No specific dose adjustment required; caution advised due to potential renal impairment and increased sensitivity in patients >65 years. |
| 1st trimester | No adequate human data; animal studies show reproductive toxicity. Risk cannot be ruled out. |
| 2nd trimester | No adequate human data; avoid use unless clearly needed. |
| 3rd trimester | May cause fetal harm if administered near term; consider risks and benefits. |
Clinical note
Comprehensive clinical and safety monograph for ZYCUBO (ZYCUBO).
| Placental transfer | Unknown, but expected to cross placenta due to molecular weight and lipophilicity. |
| Breastfeeding | No data on presence in human milk; potential for serious adverse reactions in nursing infants; decision to discontinue nursing or drug should be based on importance of drug to mother. |
| Lactation Rating |
■ FDA Black Box Warning
Immune-mediated adverse reactions: ZYCUBO can cause severe and fatal immune-mediated adverse reactions including pneumonitis, colitis, hepatitis, endocrinopathies, nephritis and renal dysfunction, skin adverse reactions, and myocarditis. Monitor for symptoms and signs; withhold or permanently discontinue based on severity.
| Serious Effects |
Hypersensitivity to active substance or excipientsConcomitant use with MAO inhibitorsSevere hepatic impairment
| Precautions | Immune-mediated adverse reactions (pneumonitis, colitis, hepatitis, endocrinopathies, nephritis, skin reactions, myocarditis), infusion-related reactions, complications of allogeneic hematopoietic stem cell transplantation, embryo-fetal toxicity. |
| Food/Dietary | No significant food interactions. ZyCubo (fidaxomicin) can be taken with or without food. No restriction on dairy, alcohol, or other foods. However, avoid grapefruit and grapefruit juice as it may theoretically affect metabolism, though not clinically significant. |
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| L5 (Contraindicated) |
| Teratogenic Risk | ZYCUBO (berotralstat) is a plasma kallikrein inhibitor indicated for hereditary angioedema. No human pregnancy data are available. In animal studies, no evidence of fetal harm was observed at exposures up to 6 times the human AUC at the recommended dose. Based on animal data, the risk of major birth defects and miscarriage is not expected to be increased; however, caution is advised due to lack of human data. First trimester: No known fetal risk from animal studies; second and third trimesters: No known risk. |
| Fetal Monitoring | Monitor for signs of bleeding (e.g., epistaxis, gingival bleeding) due to an increased risk of hemorrhage (per clinical trials). No specific fetal monitoring required; however, standard prenatal care should be maintained. Assess liver function tests periodically during pregnancy as elevations were observed in clinical studies. |
| Fertility Effects | No human data on fertility. In animal studies, no adverse effects on mating, fertility, or reproductive indices were observed in male or female rats at exposures up to 4 times the human AUC at the recommended dose. |
| Clinical Pearls | ZyCubo (fidaxomicin) is a macrocyclic antibiotic indicated for Clostridioides difficile-associated diarrhea (CDAD). It is minimally absorbed systemically, achieving high fecal concentrations with low risk of systemic toxicity. Unlike vancomycin, it is active against C. difficile and has a narrower spectrum, minimizing disruption of normal gut flora. Use for initial or recurrent CDAD; not indicated for non-CDI diarrhea. Administer with or without food. Monitor for hypersensitivity reactions, though rare. |
| Patient Advice | Take exactly as prescribed, usually twice daily for 10 days. · Complete the full course even if you feel better to prevent recurrence. · May be taken with or without food. · Notify your doctor if you develop severe watery diarrhea, abdominal pain, or fever. · Avoid use of anti-diarrheal medications unless directed by your doctor. · Inform your doctor about all other medications, especially blood thinners or antibiotics. · Contact your doctor if you experience signs of an allergic reaction: rash, hives, itching, difficulty breathing. |