Rifampicin-Induced Circulatory Shock Following Re-Exposure During Latent Tuberculosis Therapy: A Case Report

Background: Rifampicin is a cornerstone agent in the management of active and latent tuberculosis infection and is generally well tolerated. Severe systemic reactions, including circulatory shock, are rare and most commonly reported following intermittent dosing or drug re-exposure. The clinical presentation may closely mimic septic shock, posing significant diagnostic challenges. Case Presentation: A 29-year-old male receiving rifampicin 600 mg daily for latent tuberculosis infection developed acute fever, gastrointestinal symptoms, and profound hypotension within two hours of drug re-exposure after a three-week interruption. On presentation, blood pressure was 78/46 mmHg with tachycardia (128 beats/min) and elevated serum lactate (4.8 mmol/L), necessitating vasopressor support. Inflammatory markers were modestly elevated (CRP 6.5 mg/L, procalcitonin 0.18 ng/mL), serum tryptase was normal, and microbiological cultures remained negative. Hemodynamic stabilization occurred within 24 hours following supportive care and permanent discontinuation of rifampicin. Causality assessment using the Naranjo Adverse Drug Reaction Probability Scale yielded a score of 9, consistent with a definite adverse drug reaction. Conclusion: Rifampicin-induced shock is an uncommon but potentially life-threatening complication that may occur following drug re-exposure and can clinically resemble septic shock. Recognition depends on careful attention to temporal relationships, exclusion of infection, and early withdrawal of the offending agent. Clinician awareness is essential, particularly in tuberculosis-endemic settings where rifampicin use is widespread