BLENOXANE
Clinical safety rating: caution
Comprehensive clinical and safety monograph for BLENOXANE (BLENOXANE).
Bleomycin acts by binding to DNA and inducing single- and double-strand breaks via free radical formation, requiring metal ions (Fe2+, Cu+) and oxygen. It inhibits DNA, RNA, and protein synthesis, with cell cycle phase specificity (G2 and M phases).
| Metabolism | Renal excretion (mostly unchanged by glomerular filtration). No significant hepatic metabolism; enzymatic inactivation by bleomycin hydrolase (deaminase) present in tissues (low in lung and skin, contributing to toxicity). |
| Excretion | Renal (60-70% as active drug); remainder primarily hepatic metabolism with biliary excretion of metabolites |
| Half-life | Terminal elimination half-life approximately 2 hours (biphasic: initial 0.5-1 hr, terminal 2-3 hr); prolonged to ~10-20 hours in severe renal impairment (CrCl <30 mL/min) |
| Protein binding | Approximately 50-60% (primarily to albumin; no specific binding proteins identified) |
| Volume of Distribution | 0.3-0.5 L/kg (not extensively tissue-bound; distributes to pleural and peritoneal cavities with slow elimination) |
| Bioavailability | IM: ~70-80%; subcutaneous: ~60-70%; oral: negligible (<5%) |
| Onset of Action | IV: 15-30 minutes (antitumor effect); IM: 1-2 hours; subcutaneous: 2-4 hours |
| Duration of Action | Variable; antitumor effect persists 2-4 weeks; DNA synthesis inhibition lasts 24-48 hours (clinical effect may require multiple doses) |
Blenoxane is administered as 0.25–0.5 units/kg (10–20 units/m²) intravenously, intramuscularly, or subcutaneously once weekly or twice weekly. Typical adult dose: 15–30 units weekly.
| Dosage form | INJECTABLE |
| Renal impairment | For CrCl 10–50 mL/min: reduce dose by 25%; for CrCl <10 mL/min: reduce dose by 50%. No adjustment for CrCl >50 mL/min. Monitor for pulmonary toxicity. |
| Liver impairment | For Child-Pugh class B or C: reduce dose by 50% due to risk of toxicity. No specific data for Child-Pugh A; use with caution. |
| Pediatric use | Children: 0.25–0.5 units/kg (10–20 units/m²) intravenously, intramuscularly, or subcutaneously once weekly. Maximum: 30 units per dose. Adjust for renal function. |
| Geriatric use | In patients >70 years: reduce dose by 50% due to increased risk of pulmonary toxicity. Monitor renal function and adjust accordingly. Start at lower end of dosing range. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for BLENOXANE (BLENOXANE).
| Breastfeeding | Blenoxane is excreted in human milk; M/P ratio not established. Potential for serious adverse reactions in nursing infants (e.g., myelosuppression, pulmonary fibrosis). Breastfeeding is contraindicated during treatment and for at least 4 weeks after last dose. |
| Teratogenic Risk | Blenoxane (bleomycin) is a pregnancy category D drug. First trimester exposure is associated with increased risk of fetal malformations including skeletal anomalies, growth retardation, and craniofacial defects. Second and third trimester exposure may cause fetal myelosuppression, increased risk of infection, and possible low birth weight. Use only if potential benefit justifies risk to fetus. |
■ FDA Black Box Warning
Pulmonary fibrosis occurs in up to 10% of patients, with risk related to age (>70 years), total dose (>400 units), smoking, renal impairment, and prior thoracic radiation. Fatal pulmonary toxicity can occur at recommended doses. Monitor pulmonary function tests, chest X-ray, and symptoms (dyspnea, cough). Risk increases with cumulative doses above 400 units.
| Serious Effects |
["Hypersensitivity to bleomycin or any component","Severe pre-existing pulmonary disease (e.g., severe COPD, pulmonary fibrosis)","Patients with significant renal impairment (CrCl <35 mL/min) without dose adjustment"]
| Precautions | ["Pulmonary toxicity: Interstitial pneumonitis and fibrosis, monitor with pulmonary function tests (DLCO) and imaging","Cutaneous toxicity: Hyperpigmentation, erythema, vesiculation, alopecia, nail changes","Hypersensitivity reactions: Anaphylaxis, especially in lymphoma patients (test dose of 1-2 units recommended)","Renal impairment: Increased risk of toxicity; dose adjustment required if CrCl <35 mL/min","Veno-occlusive disease: Rare but reported","Extravasation: Can cause tissue necrosis, administer intravenously with care"] |
| Food/Dietary |
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| Fetal Monitoring | Monitor complete blood count with differential, renal function, liver function tests, pulmonary function tests (DLCO, spirometry), and chest X-ray baseline and periodically. In pregnancy, fetal ultrasound for growth and anatomy, consider fetal echocardiography if exposure in first trimester. Monitor for signs of pulmonary toxicity (dyspnea, crackles, infiltrates). |
| Fertility Effects | Blenoxane can cause azoospermia in males and amenorrhea in females, potentially leading to infertility. Effects may be reversible in some patients but dose-dependent; cumulative doses >400 units increase risk of permanent gonadal dysfunction. Advise fertility preservation options before treatment. |
| No specific food interactions are documented. Avoid grapefruit and grapefruit juice as they may theoretically affect metabolism via CYP3A4, but clinical significance is unknown. |
| Clinical Pearls | Blenoxane (bleomycin) is associated with pulmonary toxicity, especially in patients over 70, those with prior lung radiation, or cumulative doses >400 units. Monitor for dyspnea, crackles, and decreased DLCO. Administer test dose (1-2 units) in lymphoma patients due to risk of anaphylactoid reactions. Premedicate with acetaminophen and diphenhydramine to reduce febrile reactions. |
| Patient Advice | Report any new or worsening shortness of breath, cough, or fever immediately. · Avoid exposure to high concentrations of oxygen, including hyperbaric therapy, as it may increase lung damage risk. · You may experience flu-like symptoms including fever and chills; these can be managed with acetaminophen. · Do not receive live vaccines during treatment and avoid close contact with recently vaccinated individuals. · Use effective contraception during treatment and for at least 6 months after completion. |