Read the Medication Guide and, if available, the Patient Information Leaflet provided by your pharmacist before you start using mechlorethamine and each time you get a refill. If you have any questions, ask your doctor or pharmacist.

Use this medication as directed by your doctor, usually once a day. After taking this medication out of the refrigerator, apply it within 30 minutes, and be sure to return it to the refrigerator right after each use. Apply a small amount of medication to completely dry skin at least 4 hours before or 30 minutes after showering or washing. Let the treated area(s) dry for 5 to 10 minutes before covering with clothing. You may apply moisturizers to the treated area(s) 2 hours before or 2 hours after applying mechlorethamine.

If someone helps you apply this medication, they must wear disposable gloves. If you are applying it to yourself, you can wear disposable gloves but you do not have to. After applying, wash your hands right away, even if you have worn gloves (see also Side Effects section). Safely throw away any used gloves in the trash.

Do not cover the treated area with tight dressings or plastic bandages. Ask your doctor whether you may cover the treated area loosely with gauze.

Avoid getting this medication in or around the eyes or eyelids. It can cause pain, burns, blurred vision, and even blindness. Also, do not apply this medication inside the nose or mouth. If you accidentally get this medication in the eyes, rinse for at least 15 minutes with plenty of water, normal saline, or an eye wash solution and get medical help right away (including exam by an eye doctor). If you get this medication in the nose or mouth, rinse for at least 15 minutes with plenty of water and tell the doctor right away.

Use this medication exactly as prescribed. Do not increase your dose or use this drug more often than directed. Your condition will not improve any faster, and your risk of side effects will increase.

This medication is flammable until dry. Let the medication dry before smoking or going near an open flame.

Tell your doctor if your condition does not get better or if it gets worse.