Can You Be Allergic to Ketamine?

Yes, it is possible to have a ketamine treatment allergy; however, it is very uncommon. 

One example occurred in the 1970s when four articles reported rashes forming as a result of ketamine dosage. Three of these articles concluded with only a 1% correlation between transient rash and pediatric patients with ketamine-induced procedures. The studies determined that the morbilliform rash was a probable adverse drug reaction to ketamine. 

There have also been reported cases of clinical reactions to ketamine consistent with anaphylaxis. For example, one case reported a patient with no significant past medical history diagnosis sedated with intramuscular ketamine. While they did have seasonal allergies and occasionally triggered environmental asthma allergies, the patient did not have any known allergy to over-the-counter pain medication. However, after only two minutes of administration, the patient was afflicted with facial edema and a urticarial rash across the face and torso. She also seemed to have difficulty breathing with associated wheezing and oxygen desaturation while under sedation. Following emergency medical help and other drugs to diffuse the urticarial rash, the patient’s allergy symptoms resolved, and she recovered completely after 30 minutes. 

Sometimes, ketamine is used alongside other drugs that cause drowsiness or slowed breathing. Such substances include: 

• Opioid medications; 
• A sleeping pill; 
• A muscle relaxer; 
• Medicine for anxiety or seizures.

Other drugs may affect ketamine and increase the possibility of anaphylaxis when used simultaneously. According to certain studies, anaphylactic reactions only occur with ketamine when it is co-administered with other agents. Instead, adverse drug reactions are more commonly related to immune-mediated hypersensitivity or IgE type I allergic reactions.