Can Imipenem (a carbapenem antibiotic) cause allergic reactions?

From the Guidelines

Imipenem can cause allergic reactions, and patients with a history of penicillin or cephalosporin allergies have a higher risk of cross-reactivity due to similarities in their beta-lactam ring structures. This carbapenem antibiotic has been associated with hypersensitivity reactions ranging from mild rashes to severe anaphylaxis, with cross-reactivity rates estimated at 1-3% 1. Common allergic manifestations include skin rashes, urticaria (hives), pruritus (itching), and fever. More severe reactions may include angioedema, bronchospasm, and anaphylactic shock.

Key Considerations

• Healthcare providers should obtain a detailed allergy history before prescribing Imipenem, especially regarding previous beta-lactam reactions 1.
• If a patient experiences symptoms of an allergic reaction while on Imipenem, the drug should be discontinued immediately and appropriate treatment initiated.
• For patients with known severe beta-lactam allergies, alternative non-beta-lactam antibiotics should be considered.
• The allergic potential of Imipenem relates to its ability to bind to proteins and form hapten-protein complexes that can trigger immune responses in susceptible individuals.

Clinical Guidance

• The time elapsed since the index reaction should be factored into the probability of an allergic reaction occurring upon re-exposure to the culprit drug 1.
• A systematic clinical approach to estimating the risk of recurrence is essential, including recording a formal allergy history in each patient reporting an antibiotic allergy 1.
• The chemical stability of Imipenem over time should be considered, with a stability of 2-3 hours at 25°C in 0.9% NaCl, requiring administration of the daily dose in several divided doses prepared just before their infusion 1.

From the FDA Drug Label

Hypersensitivity Reactions: Serious and occasionally fatal hypersensitivity (anaphylactic) reactions have been reported in patients receiving therapy with beta-lactams. If an allergic reaction to Imipenem and Cilastatin for Injection (I.V.) occurs, discontinue the drug immediately ( 5. 1). Known hypersensitivity to any component of Imipenem and Cilastatin for Injection (I.V.) ( 4) Advise patients that allergic reactions, including serious allergic reactions, could occur and that serious reactions require immediate treatment. They should report any previous hypersensitivity reactions to Imipenem and Cilastatin for Injection (I.V.), other carbapenems, beta-lactams or other allergens.

Imipenem is known to cause allergic reactions, including serious and occasionally fatal hypersensitivity (anaphylactic) reactions. Patients should be advised to report any previous hypersensitivity reactions to Imipenem and Cilastatin for Injection (I.V.), other carbapenems, beta-lactams, or other allergens. If an allergic reaction occurs, the drug should be discontinued immediately 2, 2.

• Key points:
  • Imipenem can cause allergic reactions
  • Serious and occasionally fatal hypersensitivity reactions have been reported
  • Patients should report any previous hypersensitivity reactions
  • The drug should be discontinued immediately if an allergic reaction occurs

From the Research

Imipenem Details

• Imipenem is a carbapenem antibiotic with broad-spectrum activity against various bacteria, including streptococci, methicillin-sensitive staphylococci, Neisseria, Haemophilus, anaerobes, and aerobic gram-negative nosocomial pathogens including Pseudomonas 3, 4.
• It is active against enterococci, but resistance may emerge during treatment of P. aeruginosa infections 3, 4.

Allergic Reactions

• Imipenem can cause allergic reactions, including immediate hypersensitivity reactions, which depend on the presence of preformed allergic (IgE) antibodies to several penicillin determinants 5.
• The rate of cross-reactivity of imipenem with penicillins is reported to be lower than 1% in recent studies, contrary to earlier reports of a 47.4% rate of cross-reactivity 6.
• Patients with an established IgE-mediated β-lactam allergy may tolerate ertapenem, another carbapenem antibiotic, after undergoing skin tests and graded challenges to assess tolerability 6.

Side Effects and Usage

• The principal toxic effects of imipenem include nausea and vomiting, which occur during intravenous infusion, and seizures, which develop in 1 to 3% of treated patients, particularly in those with renal insufficiency and underlying disease of the central nervous system 4.
• Imipenem should be considered for treatment of mixed bacterial infections and treatment of resistant aerobic gram-negative bacteria that are not susceptible to other beta-lactam agents, but its use should be judicious to prevent promoting resistance 3, 4.