Home Drug Guide Busulfan

Drug Guide

Generic Name

Busulfan

Brand Names Myleran, Busulfex

Classification

Therapeutic: Antineoplastic agent

Pharmacological: Alkylating agent

FDA Approved Indications

  • Chronic myelogenous leukemia (CML) in chronic phase; used as part of bone marrow conditioning regimens before stem cell transplantation

Mechanism of Action

Busulfan works by alkylating DNA, leading to cross-linking of DNA strands, which prevents cell replication and causes cell death, primarily affecting rapidly dividing cells like cancer cells.

Dosage and Administration

Adult: The dosing varies based on regimen and condition; typically, an oral dose of 4-6 mg daily in divided doses for several days, or intravenous dosing as per protocol; close monitoring is required.

Pediatric: Dosing determined by body surface area or weight, with careful monitoring; consult oncology protocols.

Geriatric: Use with caution; consider decreased organ function and comorbidities affecting drug metabolism and clearance.

Renal Impairment: Adjust dose as needed; dose adjustment guidelines are limited, so close monitoring of toxicity is essential.

Hepatic Impairment: No specific adjustments established; use caution, considering hepatic function.

Pharmacokinetics

Absorption: Oral bioavailability varies; intravenous administration provides predictable plasma levels.

Distribution: Widely distributed across tissues, crosses the blood-brain barrier.

Metabolism: Metabolized hepatically; exact pathways are not fully understood.

Excretion: Primarily excreted in urine.

Half Life: Approximate elimination half-life is about 2-3 hours, but effective half-life during therapy depends on infusion duration and regimen.

Contraindications

  • Hypersensitivity to busulfan or other alkylating agents

Precautions

  • Use with caution in patients with existing bone marrow suppression, hepatic impairment, or renal impairment; risk of severe myelosuppression, pulmonary toxicity, and secondary malignancies; pregnancy category D—risk to fetus; effective contraception required for males and females during therapy.

Adverse Reactions - Common

  • Myelosuppression (Very common)
  • Nausea and vomiting (Common)
  • Stomatitis (Common)
  • Alopecia (Common)

Adverse Reactions - Serious

  • Seizures (Rare)
  • Pulmonary fibrosis or toxicity (Rare)
  • Secondary malignancies (e.g., leukemia) (Rare)

Drug-Drug Interactions

  • Other myelosuppressive agents
  • CYP450 enzyme inducers or inhibitors may alter metabolism

Drug-Food Interactions

  • Avoid alcohol and grapefruit juice, which can affect liver enzymes

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor complete blood counts, liver and renal function, signs of infection, pulmonary status.

Diagnoses:

  • Risk for infection
  • Impaired tissue integrity
  • Risk for bleeding

Implementation: Administer as prescribed, monitor for toxicity, educate patient on infection prevention, and promptly report adverse effects.

Evaluation: Regularly evaluate blood counts, organ functions, and patient symptoms to adjust therapy accordingly.

Patient/Family Teaching

  • Report signs of infection, bleeding, or unusual bleeding gums.
  • Follow precautions to prevent infections.
  • Use effective contraception during and for some months after therapy.
  • Avoid alcohol and hepatotoxic drugs.

Special Considerations

Black Box Warnings:

  • Severe myelosuppression leading to infection, hemorrhage, and potentially fatal implementing.
  • Secondary malignancies, especially leukemia.
  • Potential for pulmonary toxicity.

Genetic Factors: Genetic polymorphisms in glutathione S-transferases (GSTs) may influence drug metabolism and toxicity.

Lab Test Interference: May cause changes in liver function tests, blood counts.

Overdose Management

Signs/Symptoms: Severe myelosuppression, nausea, vomiting, seizures, pulmonary symptoms.

Treatment: Supportive care, including hematopoietic growth factors, anticonvulsants for seizures, and broad-spectrum antibiotics for infections; no specific antidote.

Storage and Handling

Storage: Store at room temperature, protected from moisture and light.

Stability: Stable under proper storage conditions for the duration specified in the package insert.

🛡️ 5 Critical Medication Safety Tips for Nurses

1

Triple-Check High-Risk Medications

Always have another nurse verify insulin, heparin, warfarin, and chemotherapy drugs. These "high-alert" medications cause the most serious errors. Check concentration, dose calculation, and pump settings twice.

2

Know Look-Alike, Sound-Alike Drugs

Common mix-ups: hydromorphone/morphine, Celebrex/Celexa, Zyprexa/Zyrtec. Always use BOTH generic and brand names, read labels twice, and use barcode scanning when available. One wrong letter can be fatal.

3

Assess Before AND After Giving Meds

Check vitals before cardiac meds, pain levels before analgesics, and blood glucose before insulin. Always reassess within 30 minutes to evaluate effectiveness and watch for adverse reactions.

4

Watch for Drug Interactions

Common dangerous combinations: warfarin + aspirin (bleeding), ACE inhibitors + potassium (hyperkalemia), digoxin + diuretics (toxicity). Always check drug interactions before administering new medications.

5

Educate Your Patients

Teach patients medication names, purposes, major side effects, and what to report. Informed patients catch errors and improve compliance. Always encourage questions - an educated patient is a safer patient.

⚡ Remember: When in doubt, don't give it out! It's always safer to double-check than regret later.

⚠️ Medical Disclaimer

This drug guide is for educational purposes only and is NOT intended for clinical use. Always consult current prescribing information, healthcare providers, and institutional protocols before administering any medication. Do not use this information for patient care decisions.