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Mechlorethamine (Topical application)

Generic name: mechlorethamine [ me-klor-ETH-a-meen ]
Drug class: Topical antineoplastics

Medically reviewed by Last updated on Mar 18, 2023.

Uses for mechlorethamine

Mechlorethamine topical is used to treat a type of skin cancer called mycosis fungoides-type T-cell lymphoma in patients who have received previous skin treatment. It belongs to the group of cancer medicines called alkylating agents. Mechlorethamine interferes with the growth of cancer cells, which are eventually destroyed.

This medicine is available only with your doctor's prescription.

Before using mechlorethamine

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:


Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.


Appropriate studies have not been performed on the relationship of age to the effects of mechlorethamine topical in the pediatric population. Safety and efficacy have not been established.


Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of mechlorethamine topical in the elderly. However, elderly patients are more likely to have unwanted skin reactions, which may require caution in patients using this medicine.

Breast Feeding

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Interactions with Medicines

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. Tell your healthcare professional if you are taking any other prescription or nonprescription (over-the-counter [OTC]) medicine.

Interactions with Food/Tobacco/Alcohol

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Proper use of mechlorethamine

It is very important that you use this medicine only as directed by your doctor. Do not use more of it, do not use it more often, and do not use it for a longer time than your doctor ordered.

This medicine is only for use on the skin. Do not get it in your eyes, nose, or mouth. Do not use it on skin areas that have cuts, scrapes, or burns. If it does get on these areas, rinse it off right away using soap and water for at least 15 minutes. Remove contaminated clothing. Check with your doctor if any irritation continues after washing the area with soap and water.

To use:

  • Take the tube out of the refrigerator. Apply the medicine right away or within 30 minutes.
  • Apply a thin layer of this medicine to completely dry skin at least 4 hours before or 30 minutes after showering or washing.
  • Place the medicine in the original box and return it to the refrigerator.
  • Allow the treated areas to dry for 5 to 10 minutes before covering with clothing.
  • Do not bandage or wrap the treated skin.
  • Avoid fire, flames, and smoking until the medicine has dried.
  • Wash your hands with soap and water after touching and applying the medicine.
  • Caregivers must wear disposable nitrile gloves when applying this medicine. Wash your hands with soap and water after removing the gloves.
  • Moisturizers are permitted on the treated areas 2 hours before or 2 hours after applying the medicine.

This medicine comes with a Medication Guide. Read and follow the instructions carefully. Ask your doctor if you have any questions.


The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

  • For topical dosage form (gel):
    • For T-cell lymphoma skin cancer:
      • Adults—Apply once a day to the affected skin area.
      • Children—Use and dose must be determined by your doctor.

Missed Dose

If you miss a dose of this medicine, apply it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule.


Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Ask your healthcare professional how you should dispose of any medicine you do not use.

Store in the refrigerator. Do not freeze.

Keep this medicine away from food in the refrigerator.

Throw empty tube and used disposable gloves in the trash can. Make sure children and pets do not have contact with the tube and gloves. Discard any unused medicine after 60 days.

Precautions while using mechlorethamine

It is very important that your doctor check your progress at regular visits for any unwanted effects that may be caused by this medicine.

Using this medicine while you are pregnant can harm your unborn baby. Use an effective form of birth control to keep from getting pregnant. If you think you have become pregnant while using the medicine, tell your doctor right away.

This medicine may cause serious allergic reactions, including anaphylaxis. Anaphylaxis can be life-threatening and requires immediate medical attention. Call your doctor right away if you have a rash, itching, trouble breathing, trouble swallowing, or any swelling of your hands, face, or mouth while you are using this medicine.

Do not get this medicine in your eyes. If eye contact occurs, you may have pain, burning, swelling, redness, sensitivity to light, or blurred vision. The medicine can cause permanent eye injury. If you get this medicine in your eye, rinse the eye right away for at least 15 minutes with water or an eye wash solution and call your doctor.

Avoid getting this medicine in your nose or mouth. It may cause pain, redness, or ulcers. If this occurs, rinse your nose or mouth right away for at least 15 minutes with water and call your doctor.

This medicine may cause unwanted skin reactions, including non-melanoma skin cancer. Contact your doctor right away if you have redness, swelling, itching, ulcers, or blisters on the skin.

Side Effects of mechlorethamine

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

More common

  • Blistering, crusting, irritation, itching, or reddening of the skin
  • cracked, dry, scaly skin
  • pain, swelling, tenderness, or warmth on the skin

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Less common

  • Darkening of the skin

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

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

Further information

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