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Mustargen Side Effects

Generic name: mechlorethamine

Medically reviewed by Last updated on Sep 6, 2022.

Note: This document contains side effect information about mechlorethamine. Some dosage forms listed on this page may not apply to the brand name Mustargen.

Applies to mechlorethamine: injection solution reconstituted.


  • This drug may cause tissue damage if the drug leaks from the vein. Tell your nurse if you have any redness, burning, pain, swelling, blisters, skin sores, or leaking of fluid where the drug is going into your body.

Serious side effects of Mustargen

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

  • Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
  • Signs of infection like fever, chills, very bad sore throat, ear or sinus pain, cough, more sputum or change in color of sputum, pain with passing urine, mouth sores, or wound that will not heal.
  • Signs of bleeding like throwing up or coughing up blood; vomit that looks like coffee grounds; blood in the urine; black, red, or tarry stools; bleeding from the gums; abnormal vaginal bleeding; bruises without a cause or that get bigger; or bleeding you cannot stop.
  • Feeling very tired or weak.

Other side effects of Mustargen

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.

You may report side effects to the FDA at 1-800-332-1088. You may also report side effects at

For Healthcare Professionals

Applies to mechlorethamine: injectable powder for injection.


The most commonly reported side effect was hematopoietic system depression.[Ref]


Rare (less than 0.1%): Hemolytic anemia

Frequency not reported: Lymphocytopenia, granulocytopenia, agranulocytosis, thrombocytopenia, pancytopenia, hyperheparenemia, hematopoietic system depression[Ref]


Frequency not reported: Hypersensitivity reactions, including anaphylaxis[Ref]


Frequency not reported: Nausea, vomiting, diarrhea, gum bleeding, gastrointestinal tract bleeding[Ref]


Frequency not reported: Alopecia, maculopapular skin eruption, erythema multiforme, petechiae, small subcutaneous hemorrhages[Ref]


Frequency not reported: Thrombosis, thrombophlebitis[Ref]


Frequency not reported: Vertigo, tinnitus, diminished hearing, chromosomal abnormalities, weakness, pain[Ref]


Frequency not reported: Jaundice[Ref]


Frequency not reported: Catamenia, oligomenorrhea, temporary or permanent amenorrhea, spermatogenesis, azoospermia, total germinal aplasia[Ref]


Frequency not reported: Herpes zoster[Ref]


Frequency not reported: Anorexia, hyperuricemia[Ref]

More about Mustargen (mechlorethamine)

Patient resources

Professional resources

Related treatment guides


1. "Product Information. Mustargen (mechlorethamine)." Merck & Company Inc (2001):

2. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.