Mechlorethamine – Uses, Dosage, Side Effects, Interaction

Mechanism of Action

Alkylating agents work by three different mechanisms: 1) attachment of alkyl groups to DNA bases, resulting in the DNA being fragmented by repair enzymes in their attempts to replace the alkylated bases, preventing DNA synthesis and RNA transcription from the affected DNA, 2) DNA damage via the formation of cross-links (bonds between atoms in the DNA) which prevents DNA from being separated for synthesis or transcription, and 3) the induction of mispairing of the nucleotides leading to mutations. Mechlorethamine is cell cycle phase-nonspecific. Mechlorethamine, as an alkylating agent, interferes with DNA replication and transcription of RNA, and ultimately results in the disruption of nucleic acid function.

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The alkylating agent, nitrogen mustard (HN2), is thought to cause apoptosis through the production of free oxygen radicals. To explore the mechanism of HN2-induced apoptosis, we utilized ebselen, a selenoorganic compound with potent antioxidant activity. We examined whether ebselen would inhibit apoptosis in BALB/c mouse spleen lymphocytes and human MOLT-4 leukemia cells treated with HN2 (2.5 microM) in vitro. Non-toxic concentrations (<50 micron m) of ebselen were found to prevent HN2-induced apoptosis of murine lymphocytes in a dose-dependent manner, as measured by cell viability, hypodiploid DNA formation, and phosphatidylserine externalization. However, ebselen was ineffective at preventing spontaneous apoptosis in these cells, pointing to the selectivity of its action. Furthermore, pretreatment with ebselen at 1-10 microM for 72 hr protected MOLT-4 cells from HN2-induced apoptosis and maintained cell viability and proliferation as monitored by the above-mentioned parameters. This was accompanied by the preservation of mitochondrial transmembrane potential and elevated glutathione levels and by a blockage of caspase-3 and -9 activation. In vivo, ebselen also had a marked protective effect against spleen weight loss associated with lymphocyte apoptosis in mice treated by HN2. Therefore, ebselen provides efficient protection against HN2-induced cell death in normal and tumoral lymphocytes and might prove useful as an antidote against alkylating agents.

Mechlorethamine also known as mustine, nitrogen mustard, and HN2, is the prototype anticancer chemotherapeutic drug. Successful clinical use of mechlorethamine gave birth to the field of anticancer chemotherapy. The drug is an analog of mustard gas and was derived from toxic gas warfare research. Mechlorethamine is a nitrogen mustard alkylating agent. Alkylating agents work by three different mechanisms all of which achieve the same end result – disruption of DNA function and cell death.

Indications

  • For the palliative treatment of Hodgkin’s disease (Stages III and IV), lymphosarcoma, chronic myelocytic or chronic lymphocytic leukemia, polycythemia vera, mycosis fungicides, and bronchogenic carcinoma. Also for the palliative treatment of metastatic carcinoma resulting in effusion.
  • Ledaga is indicated for the topical treatment of mycosis fungoides-type cutaneous T-cell lymphoma (MF-type CTCL) in adult patients.
  • Mechlorethamine is a nitrogen mustard and antineoplastic agent that has been in clinical use for more than 60 years, given systemically in combination with other antineoplastic agents to treat Hodgkin disease, chronic leukemias, lung cancer, and polycythemia vera. Currently, however, it is used largely as a topical gel for the therapy of cutaneous T-cell lymphomas and mycosis fungoides.
  • Mechlorethamine is an antineoplastic agent used to treat Hodgkin’s disease, lymphosarcoma, and chronic myelocytic or lymphocytic leukemia.
  • For the palliative treatment of Hodgkin’s disease (Stages III and IV), lymphosarcoma, chronic myelocytic or chronic lymphocytic leukemia, polycythemia vera, mycosis fungoides, and bronchogenic carcinoma. Also for the palliative treatment of metastatic carcinoma resulting in effusion.
  • Carcinoma, Bronchogenic
  • Chronic Lymphocytic Leukemia
  • Hodgkins Disease (HD)
  • Lymphoma, Diffuse
  • Mycosis Fungoides (MF)
  • Polycythemia Vera (PV)
  • Stage I Mycosis Fungoides
  • Malignant effusion

Contraindications

  • a bad infection
  • accumulation of a amyloid protein in organs and tissues
  • decreased function of bone marrow
  • anemia
  • increased risk of bleeding due to clotting disorder
  • decreased blood platelets
  • low levels of white blood cells
  • low levels of granulocytes, a type of white blood cell
  • high amount of uric acid in the blood
  • pregnancy
  • a patient who is producing milk and breastfeeding
  • spread of malignant cancer to the bone marrow

Dosage

Strengths: 10 mg

Malignant Disease

  • IV: 0.4 mg/kg either as a single dose or in divided doses of 0.1 to 0.2 mg/kg per day
  • Intracavitary (intrapleurally, intraperitoneal): 0.4 mg/kg
  • Intrapericardial: 0.2 mg/kg
  • The presence of edema or ascites must be considered so dosage will be based on actual weight unaugmented by these conditions.
  • The dosage varies with the clinical situation, the therapeutic response and the magnitude of hematologic depression.
  • Intravenously: Palliative treatment of Hodgkin’s disease (Stages III and IV), lymphosarcoma, chronic myelocytic or chronic lymphocytic leukemia, polycythemia vera, mycosis fungoides, and bronchogenic carcinoma.
  • Intracavitary and Intrapericardial: Palliative treatment of metastatic carcinoma resulting in pleural, peritoneal, and/or pericardial effusion.
  • Should be administered only under the supervision of a physician who is experienced in the use of cancer chemotherapeutic agents.
  • This drug is highly toxic and both powder and solution must be handled and administered with care. Inhalation of dust or vapors and contact with skin or mucous membranes, especially those of the eyes, must be avoided. Avoid exposure during pregnancy. Due to the toxic properties of this drug (e.g., corrosivity, carcinogenicity, mutagenicity, teratogenicity), special handling procedures should be reviewed prior to handling and followed diligently.
  • Extravasation of the drug into subcutaneous tissues results in a painful inflammation. The area usually becomes indurated and sloughing may occur. If leakage of drug is obvious, prompt infiltration of the area with sterile isotonic sodium thiosulfate (1/6 molar) and application of an ice compress for 6 to 12 hours may minimize the local reaction. For a 1/6 molar solution of sodium thiosulfate, use 4.14 g of sodium thiosulfate per 100 mL of Sterile Water for Injection or 2.64 g of anhydrous sodium thiosulfate per 100 mL or dilute 4 mL of Sodium Thiosulfate Injection (10%) with 6 mL of Sterile Water for Injection.

Administration advice:

  • Since this drug is highly toxic, appropriate precautions including the use of appropriate safety equipment are recommended for the preparation of this drug for parenteral administration.
  • Not for oral administration
  • Reconstitution/preparation techniques: The manufacturer’s product information should be consulted.
  • Repeated examinations of blood are mandatory as a guide to subsequent therapy.
  • The margin of safety in therapy is narrow and considerable care must be exercised in the matter of dosage.
  • Solutions of the drug should be prepared immediately before use.
  • Protect from light and humidity.

Side Effects

The Most Common

  • nausea
  • vomiting
  • loss of appetite
  • diarrhea
  • unusual tiredness or weakness
  • dizziness
  • painful, swollen joints
  • ringing in ears and difficulty hearing
  • fever, chills, sore throat, ongoing cough and congestion, or other signs of an infection
  • unusual bleeding or bruising
  • bloody or black, tarry stools
  • bloody vomit
  • vomited material that looks like coffee grounds
  • bleeding gums
  • small, round, red or purple colored spots on the skin
  • hives
  • rash
  • itching
  • difficulty breathing or swallowing
  • numbness or tingling in your hands or feet
  • irregular heartbeat

More common

  • Black, tarry stools
  • blood in urine or stools
  • cough or hoarseness
  • fever or chills
  • lower back or side pain
  • pain or redness at place of injection
  • painful or difficult urination
  • pinpoint red spots on skin
  • unusual bleeding or bruising

Rare

  • Shortness of breath, itching, or wheezing
  • Missing menstrual periods
  • painful rash
  • Dizziness
  • joint pain
  • loss of hearing
  • ringing in ears
  • swelling of feet or lower legs
  • Numbness, tingling, or burning of fingers, toes, or face
  • sores in the mouth and on lips
  • yellow eyes or skin
  • Nausea and vomiting (usually lasts only 8 to 24 hours)
  • Confusion
  • diarrhea
  • drowsiness
  • headache
  • loss of appetite
  • metallic taste
  • weakness

Drug Interactions

Pregnancy and Lactation

FDA Pregnancy Category D

Pregnancy

Mechlorethamine can cause fetal harm when administered to a pregnant woman. There are case reports of children born with malformations in pregnant women systemically administered mechlorethamine. Mechlorethamine was teratogenic in animals after a single subcutaneous administration. If this drug is used during pregnancy or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential hazard to a fetus.

Lactation

It is not known if mechlorethamine is excreted in human milk. Due to the potential for topical or systemic exposure to VALCHLOR through exposure to the mother’s skin, a decision should be made whether to discontinue nursing or the drug, taking into account the importance of the drug to the mother. Safety and effectiveness in pediatric patients have not been established.

Why is this medication prescribed?

Mechlorethamine is used to treat Hodgkin’s lymphoma (Hodgkin’s disease) and certain types of non-Hodgkin‘s lymphoma (types of cancer that begin in a type of white blood cells that normally fights infection); mycosis fungoides (a type of cancer of the immune system that first appear as skin rashes); certain types of leukemia (cancer of the white blood cells), including chronic lymphocytic leukemia (CLL) and chronic myelogenous leukemia (CML); and lung cancer. Mechlorethamine is also used to treat polycythemia vera (a disease in which too many red blood cells are made in the bone marrow). It is also used to treat malignant effusions (a condition when fluid collects in the lungs or around the heart) that are caused by cancerous tumors. Mechlorethamine is in a class of medications called alkylating agents. It works by slowing or stopping the growth of cancer cells in your body.

How should this medicine be used?

Mechlorethamine comes as powder to be mixed with liquid to be injected intravenously (into a vein) by a doctor or nurse in a medical facility. It may also be injected intraperitoneally (into the abdominal cavity), intrapleurally (into the chest cavity), or intrapericardially (into the lining of the heart). The length of treatment depends on the types of drugs you are taking, how well your body responds to them, and the type of cancer or condition you have. Ask your pharmacist or doctor for a copy of the manufacturer’s information for the patient.

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

What special precautions should I follow?

Before receiving mechlorethamine,

  • tell your doctor and pharmacist if you are allergic to mechlorethamine, any other medications, or any of the ingredients in mechlorethamine injection. Ask your pharmacist for a list of the ingredients.
  • tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take.
  • tell your doctor if you have an infection. Your doctor may not want you to receive mechlorethamine.
  • tell your doctor if you have previously received or will be receiving radiation (x-ray) therapy or other chemotherapy and if you have or have ever had any medical conditions..
  • you should know that mechlorethamine may interfere with the normal menstrual cycle (period) in women, may stop sperm production in men, and may cause infertility (difficulty becoming pregnant). However, you should not assume that you or your partner cannot become pregnant. Tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. You should not become pregnant or breast-feed while you are receiving mechlorethamine injection. Mechlorethamine may harm the fetus.
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