Penicillin Allergy and Hypersensitivity Reactions

Penicillin Allergy and Hypersensitivity Reactions

• The prevalence of documented penicillin allergy in the general population is approximately 10%.
• Beta-lactam antibiotics can cause IgE-mediated and non-IgE mediated hypersensitivity reactions.
• Skin tests, including penicillin skin testing, are a useful diagnostic tool for immediate and delayed hypersensitivity reactions to penicillin and penicillin derivatives.

Drug-Drug Interactions and Excretion

• Beta-lactam antibiotics demonstrate extensive drug-drug interactions, including interactions that induce metabolism and interactions that inhibit metabolism.
• Co-administration with probenecid can prolong the half-life of certain beta-lactam antibiotics, indicating that they are mainly excreted by the kidneys.

Clinical Considerations

• Special attention is required when using beta-lactam antibiotics with other drugs, such as thrombolytic agents or glucocorticoids, in severe bacterial meningitis.
• Co-administering linezolid with beta-lactam antibiotics can potentially improve the treatment of invasive bacterial infections in severe B-lactamase producing pathogens.

Clinical Relevance and Adverse Effects

• Beta-lactam antibiotics are an essential component of the current therapeutic armamentarium, despite the increasing problem of multi-drug resistant Gram-positive and Gram-negative bacterial pathogens.
• The clinical utility of beta-lactam antibiotics has been reduced due to increasing beta-lactamase production.
• Adverse effects of beta-lactam antibiotics are relatively rare but can include genitourinary effects like interstitial nephritis, bleeding issues like hemolytic anemia, and gastrointestinal side effects.