Optimizing the Diagnostic Approach to Cephalosporin Allergy Testing
Massachusetts General Hospital
300 participants
May 5, 2025
INTERVENTIONAL
Conditions
Summary
Cephalosporin antibiotics are commonly used but can result in allergic reactions and anaphylaxis. There is no clear diagnostic approach for cephalosporin-allergic patients, and guidance for the use of other antibiotics in allergic patients is based on side chain chemical similarity and limited skin testing evidence. This project includes a clinical trial and mechanistic studies to optimize the approach to cephalosporin allergy and advance future diagnostics.
Eligibility
Plain Language Summary
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This summary was AI-generated to explain the trial in plain language. It is not medical advice. Always discuss eligibility with your doctor before enrolling in a clinical trial.
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Interventions
Percutaneous and intradermal skin testing will be performed in all participants. Concentrations for percutaneous testing; cefazolin (330 mg/ml), cefuroxime (90 mg/ml), ceftazidime (100 mg/ml), ceftriaxone (100 mg/ml), cefepime (200 mg/ml), pre-pen (undiluted), penicillin G (10,000 U/ml), ampicillin (20 mg/ml) and histamine (6 mg/ml). Concentrations for the first intradermal testing; cefazolin (3.3mg/ml), cefuroxime (1 mg/ml), ceftazidime (1 mg/ml), ceftriaxone (1 mg/ml), cefepime (2 mg/ml), Pre-PEN (undiluted), penicillin G (1000 U/ml), ampicillin (20 mg/ml), and histamine (0.1 mg/ml). Concentrations for the second intradermal testing; cefazolin (33mg/ml), cefuroxime (10 mg/ml), ceftazidime (10 mg/ml), ceftriaxone (10 mg/ml), cefepime (20 mg/ml), Pre-PEN (undiluted), penicillin G (10,000 U/ml), ampicillin (20 mg/ml) and histamine (0.1 mg/ml). Histamine and saline will be used as positive and negative controls.
After double-blind skin testing, participants will undergo a 3-step double-blind placebo-controlled drug challenge to their culprit cephalosporin (the cephalosporin they are suspected to be allergic to, either cefazolin, ceftazidime, ceftriaxone, cefepime, cephalexin, cefaclor, cefadroxil, cefuroxime, cefpodoxime, cefdinir, or cefixime). The challenges are 1:1 randomized to the order of active drug versus placebo. In Step 1, participants will receive 1:1000 of a full dose of either the culprit drug or placebo, followed by a 30-minute observation period. In Step 2, participants will receive 1:50 of a full dose of either, followed by another 30-minute observation period. In Step 3, participants are administered the full dose of either agent, followed by a 60-minute observation period. The same testing process is repeated for the second challenge.
Participants will undergo a 3-step double-blind placebo-controlled drug challenge to a cephalosporin antibiotic that shares a similar side chain with their culprit. This will be cefepime for those allergic to ceftriaxone, cefaclor for those allergic to cephalexin, cefixime for those allergic to cefdinir, cefdinir for those allergic to cefixime, cephalexin for those allergic to cefaclor or cephadroxil, and ceftriaxone for those allergic to cefepime, cefuroxime, or cefpodoxime. The challenges are 1:1 randomized to the order of active drug versus placebo. In Step 1, participants will receive 1:1000 of a full dose of either the culprit drug or placebo, followed by a 30-minute observation period. In Step 2, participants will receive 1:50 of a full dose of either, followed by another 30-minute observation period. In Step 3, participants are administered the full dose of either agent, followed by a 60-minute observation period. The same testing process is repeated for the second challenge.
Participants will undergo a 3-step double-blind placebo-controlled drug challenge to a cephalosporin antibiotic that has a dissimilar side chain to their culprit. This will be ceftriaxone for those allergic to cefazolin, and cefazolin for those allergic to any other cephalosporin. The challenges are 1:1 randomized to the order of active drug versus placebo. In Step 1, participants will receive 1:1000 of a full dose of either the culprit drug or placebo, followed by a 30-minute observation period. In Step 2, participants will receive 1:50 of a full dose of either, followed by another 30-minute observation period. In Step 3, participants are administered the full dose of either agent, followed by a 60-minute observation period. The same testing process is repeated for the second challenge.
Participants will optionally undergo a 3-step double-blind placebo-controlled drug challenge to Amoxicillin. The challenges are 1:1 randomized to the order of active drug versus placebo. In Step 1, participants will receive 1:1000 of a full dose of either the culprit drug or placebo, followed by a 30-minute observation period. In Step 2, participants will receive 1:50 of a full dose of either, followed by another 30-minute observation period. In Step 3, participants are administered the full dose of either agent, followed by a 60-minute observation period. The same testing process is repeated for the second challenge. The order of challenge to similar vs. dissimilar cephalosporin will be randomized as well.
Locations(6)
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NCT06406114