A 30-year-old with meningococcal meningitis is started on IV penicillin G. Six hours later she develops sudden hypotension and worsening consciousness despite the organism being sensitive. The mechanism most responsible is:
- A Penicillin allergy causing anaphylaxis
- B Jarisch-Herxheimer reaction from rapid bacterial lysis releasing endotoxin ✓
- C Neurotoxicity of high-dose penicillin G
- D Development of penicillin resistance through beta-lactamase production
Correct answer: B. Jarisch-Herxheimer reaction from rapid bacterial lysis releasing endotoxin
Explanation
The Jarisch-Herxheimer reaction is a systemic inflammatory response occurring within hours of starting bactericidal antibiotics for infections with organisms that release large amounts of endotoxin or lipopolysaccharide on lysis. It presents with fever, rigors, hypotension, and clinical deterioration despite appropriate antibiotic selection. It occurs classically with spirochetes (syphilis, leptospirosis) but also with Neisseria meningitidis. Treatment is supportive; the antibiotic should not be stopped.
Reference: KD Tripathi, Essentials of Medical Pharmacology, 8th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.