Description and Brand Names

Drug information provided by: Micromedex

US Brand Name

  1. Ontak


Denileukin diftitox is used to treat persistent or recurrent cutaneous T-cell lymphoma. This is a rare type of cancer that affects certain white blood cells and causes lesions to develop on the skin.

Denileukin diftitox interferes with the growth of cancer cells, which are eventually destroyed. Since the growth of normal cells may also be affected by the medicine, other effects may also occur. Some of these may be serious and must be reported to your doctor. Some effects may occur after treatment with denileukin diftitox.

Denileukin diftitox is to be administered only by or under the supervision of your doctor or other health care professional.

This product is available in the following dosage forms:

  • Injectable
  • Solution

Before Using

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 denileukin diftitox in the pediatric population. Safety and efficacy have not been established.


Although appropriate studies on the relationship of age to the effects of denileukin diftitox have not been performed in the geriatric population, geriatric-specific problems are not expected to limit the usefulness of denileukin diftitox in the elderly.


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.

Drug Interactions

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.

Other Interactions

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.

Other Medical Problems

The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:

  • Heart disease—Use with caution. May increase risk for more serious side effects.

Proper Use

Medicines used to treat cancer are very strong and can have many side effects. Before receiving this medicine, make sure you understand all the risks and benefits. It is important for you to work closely with your doctor during your treatment.

A nurse or other trained health professional will give you this medicine in a hospital or cancer treatment center. This medicine is given through a needle placed in one of your veins. The medicine must be injected slowly, so your IV tube will need to stay in place for 30 to 60 minutes.

This medicine is usually given every day for 5 days. This 5-day treatment is given again every 21 days for several months, or until your body responds to the medicine.

Missed Dose

This medicine needs to be given on a fixed schedule. If you miss a dose, call your doctor, home health caregiver, or treatment clinic for instructions.


It is very important that your doctor check your progress at regular visits to make sure that this medicine is working properly. Blood tests may be needed to check for unwanted effects.

This medicine may cause a serious side effect called an infusion reaction. This can be life-threatening and requires immediate medical attention. Tell your doctor or nurse right away if you have fever, chills, breathing problems, chest pain, fast or pounding heartbeat, hives, or rash after you receive the injection.

Call your doctor right away if you have dizziness, faintness, or lightheadedness when getting up from a lying or sitting position; rapid weight gain; or swelling of hands, ankles, feet, or lower legs. These may be symptoms of a rare but serious condition called capillary leak syndrome.

Check with your doctor right away if you have any vision changes (e.g., decrease in vision, loss of color vision) while you are using this medicine. Your doctor may want you to have your eyes checked by an eye doctor.

Side Effects

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 or nurse immediately if any of the following side effects occur:

More common

  1. Back pain
  2. bloating or swelling of the face, arms, hands, lower legs, or feet
  3. blurred vision
  4. body aches or pain
  5. chest pain
  6. confusion
  7. cough
  8. difficulty with breathing
  9. difficulty with moving
  10. difficulty with swallowing
  11. dizziness, faintness, or lightheadedness when getting up from a lying or sitting position suddenly
  12. ear congestion
  13. fast or irregular heartbeat
  14. feeling unusually cold
  15. fever or chills
  16. headache
  17. loss of appetite
  18. loss of strength or energy
  19. loss of voice
  20. muscle aching or cramping
  21. muscle pains or stiffness
  22. nasal congestion
  23. nausea
  24. pain in the joints and muscles
  25. rapid weight gain
  26. rash
  27. runny nose
  28. shivering
  29. shortness of breath
  30. sneezing
  31. sore throat
  32. sweating
  33. swollen joints
  34. tightness in the chest
  35. tingling of the hands or feet
  36. unusual tiredness or weakness
  37. unusual weight gain or loss
  38. vomiting
  39. warmth and flushing of the skin
  40. wheezing

Less common

  1. Abdominal pain, severe
  2. black, tarry stools
  3. blood in the urine or stools
  4. cloudy urine
  5. cough or hoarseness accompanied by fever or chills
  6. headache, severe
  7. loss of coordination
  8. lower back or side pain accompanied by fever or chills
  9. pain in the groin or leg
  10. painful or difficult urination accompanied by fever or chills
  11. pinpoint red spots on the skin
  12. slurring of speech
  13. sudden vision changes
  14. swelling or pain at the injection site
  15. unusual bleeding or bruising
  16. weakness of the arm and leg


  1. Dry, puffy skin
  2. increased heart rate
  3. weight gain

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:

More common

  1. Change in taste
  2. diarrhea
  3. itching
  4. loss of taste

Less common

  1. Constipation
  2. indigestion
  3. numbness or tingling of the fingers, toes, or face
  4. runny nose
  5. trouble with sleeping

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.