Rapid Desensitization after a Type I Hypersensitivity Reaction to Ceftazidime/Avibactam

Discussion

This is the first reported case in the literature to describe a type I hypersensitivity reaction with rapid IV induction of tolerance to ceftazidime/avibactam. We describe his reaction as type I hypersensitivity because the patient developed immediate generalized urticaria and flushing. Use of a safe desensitization protocol, demonstrated in this case report, is paramount to optimal management of infections in patient populations with severely decreased lung function, such as CP.^5-7 It provides a safe and effective technique to maintain patients on first line, preferred therapy, despite their increased risk of potentially life-threatening allergic reactions.

Interestingly, this patient previously tolerated penicillins and cephalosporins without adverse reactions, suggesting the possibility of a non–IgE-mediated vs an IgE-mediated mechanism to the hypersensitivity reaction. The patient also was receiving oxycodone at the time of his reaction, and oxycodone can cause nonspecific mast cell degranulation. Additional information from skin testing to ceftazidime/avibactam could help determine whether the patient had an IgE-mediated hypersensitivity reaction. This information could help clarify the culprit agent and guide further avoidance recommendations.

Unfortunately, because the patient was critically ill, skin testing was not performed, and he underwent an urgent antibiotic desensitization with success. It was recommended that the patient follow up in the allergy and immunology clinic for further evaluation with skin testing to ceftazidime/avibactam as well as other β-lactams to determine his future risk of reaction. Unfortunately, he was lost to follow-up.

Frequent IV antibiotic use is a risk factor for the development of antibiotic allergies.^8,9 This patient had received many prior courses of IV antibiotics, and this factor most likely contributed to his immediate hypersensitivity reaction to ceftazidime/avibactam. Fortunately, he tolerated a rapid induction of tolerance.

As life expectancies for patients with chronic medical conditions that involve recurrent infections increase, the associated emergence of multidrug-resistant pathogens and necessity for use of novel combination antibiotics should prompt further investigation of nonirritating doses of these drugs for skin testing in the case of drug hypersensitivities. This information would be essential for skin prick testing and determination of whether patients have a true IgE-mediated reaction to these antibiotics.

Conclusions

This is the first case report demonstrating a successful rapid induction of tolerance for the antibiotic ceftazidime/avibactam. Fortunately, the patient tolerated the desensitization procedure without further adverse reactions, and he had a resolution of his infection.