Generic drug: mechlorethamine

Brand name: Valchlor

What is Valchlor (mechlorethamine), and how does it work?

Valchlor is a prescription medicine used on the skin (topical) to treat people with Stage 1A and 1B mycosis fungoides-type cutaneous T-cell lymphoma, a type of blood cancer, who have received previous skin treatment. It is not known if Valchlor is safe and effective in children.

Do not use Valchlor if you are severely allergic to mechlorethamine. Tell your healthcare provider if you have had an allergic reaction to mechlorethamine.

What are the side effects of Valchlor?

Valchlor can cause serious side effects, including:

Get medical help right away if Valchlor gets in your eyes, mouth, or nose.

  • Risk of Secondary Exposure to Valchlor. You may have a risk of inflammation of your skin (dermatitis), injury to your eyes, mouth, or nose, and certain types of cancers. Caregivers who accidentally come into contact with Valchlor must wash the affected area with soap and water right away for at least 15 minutes and remove any contaminated clothing.
  • Inflammation of your skin (dermatitis) is common with Valchlor and may sometimes be severe. Your risk for dermatitis is increased if Valchlor is applied to your face, genital area, anus, or skin folds. Tell your healthcare provider if you develop skin reactions such as redness, swelling, itching, blisters, ulcers, and skin infections.
  • Increased risk of certain types of skin cancers. Certain types of skin cancer can develop on areas of your skin that are treated with Valchlor and areas of your skin that are not treated with Valchlor. Your healthcare provider will check your skin for skin cancers during and after your treatment with Valchlor. Tell your healthcare provider if you get any new skin lesions.

The most common side effects of Valchlor include: redness, swelling, itching, skin ulcers or blisters, skin infection, and darkening of areas of your skin. Valchlor may cause fertility problems in females and males. This could affect the ability to become pregnant. Talk to your healthcare provider if this is a concern for you.

These are not all the possible side effects of Valchlor.

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What is the dosage for Valchlor?

Dosing And Dose Modification

For Topical Dermatological Use Only
  • Apply a thin film of Valchlor gel once daily to affected areas of the skin.
  • Stop treatment with Valchlor for any grade of skin ulceration, blistering, or moderately-severe or severe dermatitis (i.e., marked skin redness with edema).
  • Upon improvement, treatment with Valchlor can be restarted at a reduced frequency of once every 3 days.
  • If reintroduction of treatment is tolerated for at least one week, the frequency of application can be increased to every other day for at least one week and then to once daily application if tolerated.

Application Instructions

Valchlor is a cytotoxic drug. Follow applicable special handling and disposal procedures.

Patients must wash hands thoroughly with soap and water after handling or applying Valchlor.

Caregivers must wear disposable nitrile gloves when applying Valchlor to patients and wash hands thoroughly with soap and water after removal of gloves. If there is accidental skin exposure to Valchlor, caregivers must immediately wash exposed areas thoroughly with soap and water for at least 15 minutes and remove contaminated clothing.

Patients or caregivers should follow these instructions when applying Valchlor:

  • Apply immediately or within 30 minutes after removal from the refrigerator. Return Valchlor to the refrigerator immediately after each use.
  • Apply to completely dry skin at least 4 hours before or 30 minutes after showering or washing. Allow treated areas to dry for 5 to 10 minutes after application before covering with clothing.
  • Emollients (moisturizers) may be applied to the treated areas 2 hours before or 2 hours after application.
  • Do not use occlusive dressings on areas of the skin where Valchlor was applied.
  • Avoid fire, flame, and smoking until Valchlor has dried.


Skin Cancer Symptoms, Types, Images See Slideshow

What drugs interact with Valchlor?

No drug interaction studies have been performed with Valchlor. Systemic exposure has not been observed with topical administration of Valchlor; therefore, systemic drug interactions are not likely.

Is Valchlor safe to use while pregnant or breastfeeding?

  • Based on case reports in humans, findings in animal reproduction studies, its mechanism of action, and genotoxicity findings, mechlorethamine may cause fetal harm.
  • Available published case reports in pregnant women receiving intravenous mechlorethamine demonstrate that mechlorethamine can cause major birth defects when a pregnant woman is systemically exposed.
  • There are no data on the presence of mechlorethamine or its metabolites in human milk, the effects of the drug on the breastfed child, or the effects of the drug on milk production.
  • Because of the potential for topical or systemic exposure to Valchlor through exposure to the mother's skin and the potential for serious adverse reactions in the breastfed child from mechlorethamine, advise patients not to breastfeed during treatment with Valchlor.

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Report Problems to the Food and Drug Administration

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

Medically Reviewed on 3/29/2021
All sections courtesy of the U.S. Food and Drug Administration