Drug desensitization

Why does a patient need desensitization?

When someone is allergic to a drug, their body reacts to it in an unsafe way. Sometimes a patient needs this treatment. If there are no other medicines that can be taken, a desensitization may be tried.

What is desensitization?

Desensitization is a process.  Tiny doses of the medicine are given very slowly so the body does not react to the medicine. This effect is only short-term. If  the medicine is stopped, a desensitization would be needed again. 

Common medicine allergies treated with desensitization include:

• Aspirin.
• Antibiotics.
• Chemotherapy medicines.

What do I need to do before the procedure?

• You will need to sign a consent form for the desensitization procedure. The consent also gives  permission to treat any reactions
• You will be given special instructions about any medicines that need to be stopped or started before the procedure.

What happens during the procedure?

• The medicine is given in very small amounts by mouth or through an IV. The amount will slowly increase over time. This means it will take many hours to get the full dose.
• Most often, you will need to stay overnight in the intensive care unit (ICU) to be watched and to get your next dose.
• If you have a reaction, it will be treated with other medicines. The procedure will keep going if it is safe. Any life-threatening reaction will stop the procedure.

Are there any risks?

You will be getting a medicine that you are allergic to. Because of this, there is a risk for reactions.  Some of the reactions may result in the need for life saving medicines, like  epinephrine. In rare cases, desensitization can cause a severe reaction that leads to death. For these reasons, all patients are closely watched in the Intensive Care Unit (ICU). 

The risks are higher when:

• Medicine is given through an IV.
• You are very young
• You are elderly.
• You have a history of heart disease.

What are the possible reactions?

Serious Reactions: These can be very serious and can lead to death if they are not treated. Tell the nurse right away if you have any of the following:

• Hives. Rash, swelling or itching of more than one part of your body
• Swelling. Any part of your body, inside or out. This includes the mouth, tongue and throat. It can be one or many parts of your body.
• Breathing problems. Shortness of breath, coughing, wheezing or chest tightness.
• Other. Repeated sneezing, dizziness, sick stomach or just not “feeling right”
• Anaphylactic shock. This is the most serious allergic reaction and the above symptoms can lead to this. It can happen any time after the medicine is taken.

If there is a serious or anaphylactic reaction, emergency medicine will be given right away.

What happens after the procedure?

It is important that you do not do not miss even one dose of this medicine. Take it as prescribed. If you miss a dose of your medicine, the reaction will come back and it could be severe.

If you need this medicine again, or if you miss any doses, you will have to do the desensitization procedure again.