Bone Marrow Suppression: For patients receiving Melphalan as part of a conditioning regimen, myeloablation occurs in all patients. Do not begin the conditioning regimen if a stem cell product is not available for rescue. Monitor complete blood counts, provide supportive care for infections, anemia and thrombocytopenia until there is adequate hematopoietic recovery.Gastrointestinal Toxicity: For patients receiving Melphalan as part of a conditioning regimen, nausea, vomiting, mucositis, and diarrhea may occur in over 50% of patients. Use prophylactic antiemetic medication. Provide supportive care for nausea, vomiting, diarrhea, and mucositis. The frequency of grade 3/4 mucositis in clinical studies was 13%. Provide nutritional support and analgesics for patients with severe mucositis.Hepatotoxicity: Hepatic disorders ranging from abnormal liver function tests to clinical manifestations such as hepatitis and jaundice have been reported after treatment with melphalan. Hepatic veno-occlusive disease has also been reported. Monitor liver chemistries.Hypersensitivity: Acute hypersensitivity reactions, including anaphylaxis, have occurred in approximately 2% of patients who received an intravenous formulation of melphalan. Symptoms may include urticaria, pruritus, edema, and skin rashes and, in some patients, tachycardia, bronchospasm, dyspnea, and hypotension. Discontinue treatment with Melphalan for serious hypersensitivity reactions.Secondary Malignancies: Melphalan has been shown to cause chromatid or chromosome damage in humans. Secondary malignancies such as myeloproliferative syndrome or acute leukemia have been reported in multiple myeloma patients treated with melphalan-containing chemotherapy regimens. The potential benefit of Melphalan therapy must be considered against the possible risk of the induction of a secondary malignancy.Embryo-Fetal Toxicity: Based on its mechanism of action, Melphalan can cause fetal harm when administered to a pregnant woman. Melphalan is genotoxic, targets actively dividing cells, and was embryolethal and teratogenic in rats. Advise pregnant women of the potential risk to a fetus. Advise females of reproductive potential to use effective contraception during treatment with Melphalan and for 6 months after the last dose. Advise males with female partners of reproductive potential to use effective contraception during treatment with Melphalan and for 3 months after the last dose.Infertility: Melphalan-based chemotherapy regimens have been reported to cause suppression of ovarian function in premenopausal women, resulting in persistent amenorrhea in approximately 9% of patients. Reversible or irreversible testicular suppression has also been reported.