Drug desensitization carries higher risks than immunotherapy. The therapy is usually recommended only when a patient's health requires the use of a specific drug for which there are no adequate substitutes. The main risks of desensitization include:

• Therapy failure. Drug desensitization therapy is not effective with all medication or for all patients. If the therapy does not work, alternative (if less effective) therapies may be needed to control the medical condition.
  
  
• Severe reaction. Whenever allergic individuals come into contact with the allergen to which they are sensitive, a severe allergic reaction is possible. The risk is higher with drug allergies, which is a common trigger of anaphylactic shock. Desensitization should always take place in a clinical or hospital setting under the supervision of an allergy specialist (allergist/immunologist).
  

  

Other considerations are the state of the patient’s health. Exposure to the allergen during desensitization may cause an allergic reaction. If a patient is in poor health, then even minor reactions could pose significant health risks. The risk of causing an allergic reaction may outweigh the potential benefits for patients with heart problems or life-threatening conditions.