Melfalanhydrochloride Sun (Melphalan)

Melphalan is an alkylating chemotherapy agent used in several hematologic and solid‑tumor indications.

• Multiple myeloma: reduces malignant plasma‑cell proliferation, decreases paraprotein levels, and prolongs overall survival in adult patients.
• Ovarian cancer: enhances tumor shrinkage, improves progression‑free survival, and augments response when used with platinum‑based regimens.
• Malignant melanoma: delivers cytotoxic activity to metastatic melanoma cells, contributing to disease control in refractory cases.
• Chronic lymphocytic leukemia: induces apoptosis of proliferating lymphocytes, leading to remission and disease stabilization.

• Melphalan is a nitrogen‑mustard alkylating agent that enters cells and forms covalent bonds with DNA bases, creating intra‑ and interstrand cross‑links. These cross‑links distort the DNA helix, impede replication and transcription, and activate DNA‑damage response pathways, leading to cell‑cycle arrest and programmed apoptosis in rapidly dividing malignant cells, while relatively sparing quiescent normal tissues. The resultant myelosuppression reflects its effect on bone‑marrow progenitors.

Melphalan may cause a range of adverse reactions, varying from mild, self‑limiting symptoms to severe, potentially life‑threatening conditions that require medical intervention.

Common Side Effects

• Nausea and vomiting: transient gastrointestinal upset that may require antiemetic therapy.
• Fatigue: generalized tiredness affecting daily activities.
• Myelosuppression (neutropenia, anemia, thrombocytopenia): reduced blood cell counts leading to infection risk and bleeding.
• Alopecia (hair loss): reversible loss of scalp and body hair.
• Mucositis: painful inflammation of the mouth and gastrointestinal lining.

Serious or Rare Side Effects

• Secondary malignancies (e.g., acute leukemia): rare development of new cancers after treatment.
• Severe infections due to neutropenia: life‑threatening bacterial or fungal infections.
• Hemorrhagic cystitis: bladder inflammation with bleeding, often related to metabolite accumulation.

When using melphalan, careful monitoring and specific precautions are essential to minimize risks.

• Monitor blood counts: perform regular CBC tests to detect myelosuppression early.
• Assess renal function: evaluate creatinine clearance before each cycle to adjust dosing.
• Avoid use in pregnancy: melphalan is contraindicated; ensure effective contraception for women of childbearing potential.
• Use protective measures for bladder: maintain adequate hydration and consider mesna to reduce hemorrhagic cystitis risk.
• Limit concurrent radiation: avoid high‑dose radiotherapy during treatment to prevent additive toxicity.
• Store at 2-8°C: keep refrigerated, protect from light, do not freeze or shake.

Melphalan can interact with other medicines, affecting its efficacy or toxicity.

Major Interactions (Avoid)

• Concurrent use with other alkylating agents: markedly increases the risk of severe myelosuppression and cumulative DNA damage.
• High‑dose radiation therapy: additive bone‑marrow toxicity may lead to prolonged pancytopenia.
• Live vaccines: immunosuppression from melphalan can permit uncontrolled replication of vaccine organisms.

Moderate Interactions (Monitor Closely)

• Nephrotoxic drugs (e.g., cisplatin, aminoglycosides): concurrent administration may exacerbate renal impairment and affect melphalan clearance.
• Anticoagulants (warfarin, heparin): thrombocytopenia from melphalan can heighten bleeding risk, requiring closer INR monitoring.
• CYP450 inducers or inhibitors: alterations in enzyme activity may modify melphalan plasma concentrations, affecting efficacy and toxicity.