Drug Guide
Melphalan
Classification
Therapeutic: Antineoplastic agent
Pharmacological: Alkylating agent
FDA Approved Indications
- Multiple myeloma
- Ovarian carcinoma
Mechanism of Action
Melphalan is an alkylating agent that causes cross-linking of DNA strands, leading to defective DNA synthesis and cell death, particularly in rapidly dividing cancer cells.
Dosage and Administration
Adult: Dose varies based on indication; typically 0.2-0.25 mg/kg/day for multiple myeloma, administered orally or intravenously, often in cycles.
Pediatric: Not commonly used; dosage and safety are not well established.
Geriatric: Adjustments may be necessary based on renal function and overall health.
Renal Impairment: Use with caution; dose adjustments may be required depending on renal function.
Hepatic Impairment: No specific guidelines; use cautiously and monitor hepatic function.
Pharmacokinetics
Absorption: Well absorbed orally.
Distribution: Widely distributed throughout body tissues; crosses the blood-brain barrier minimally.
Metabolism: Extensively hepatic via hydrolysis and conjugation.
Excretion: Primarily renal.
Half Life: Approximately 2-3 hours.
Contraindications
- Hypersensitivity to melphalan
- Myelosuppression (active or severe)
Precautions
- Bone marrow suppression risk
- Infection risk
- Pregnancy and lactation (category C): use only if the potential benefit justifies the risk
- Monitoring liver and kidney function during therapy
Adverse Reactions - Common
- Myelosuppression (Very common)
- Nausea (Common)
- Mucositis (Common)
Adverse Reactions - Serious
- Severe myelosuppression leading to infection, bleeding (Serious/Common)
- Secondary malignancies (leukemia, other cancers) (Rare)
- Alopecia (Common)
Drug-Drug Interactions
- Other myelosuppressive agents
- Cytotoxic chemotherapies
- Radiation therapy
Drug-Food Interactions
N/ADrug-Herb Interactions
N/ANursing Implications
Assessment: Monitor CBC, renal and hepatic function, observe for signs of infection or bleeding.
Diagnoses:
- Risk for infection
- Risk for bleeding
- Imbalanced nutrition: less than body requirements
Implementation: Administer as prescribed; monitor blood counts regularly; provide infection control measures.
Evaluation: Assess for adverse effects, effectiveness of therapy, and patient's tolerance.
Patient/Family Teaching
- Report signs of infection, bleeding, or unusual bruising immediately.
- Use effective contraception during and for some months after therapy.
- Avoid pregnancy; discuss fertility concerns with healthcare provider.
- Expect side effects like nausea and hair loss; manage symptoms as advised.
- Maintain good nutrition and hydration.
Special Considerations
Black Box Warnings:
- Myelosuppression can be severe and life-threatening
- Secondary malignancies
Genetic Factors: No specific genetic markers influence melphalan response.
Lab Test Interference: May cause false-positive urinary catecholamine tests.
Overdose Management
Signs/Symptoms: Severe myelosuppression, bleeding, infection, nausea, vomiting.
Treatment: Supportive care; no specific antidote. Hematopoietic growth factors or stem cell support may be considered in severe cases.
Storage and Handling
Storage: Store at controlled room temperature, protected from light.
Stability: Stable when stored properly; discard unused portions according to protocols.