A Case of Trimethoprim‐Sulfamethoxazole Associated Aseptic Meningitis

Most cases of aseptic meningitis, or nonsuppurative meningitis, are caused by viruses or systemic diseases. Nonetheless, drug-induced aseptic meningitis should be considered in the differential diagnosis, particularly with the recent use of antibiotics and nonsteroidal anti-inflammatory drugs. We describe a case of meningitis associated with the use of Trimethoprim-Sulfamethoxazole (TMP-SMX) in a 72-year-old male with comorbidities. A 72-year-old male with a history of diabetes, hypertension, Parkinson's disease, benign prostatic hyperplasia, and a recent use of TMP-SMX for a urinary tract infection (UTI) presented with altered mental status, neck rigidity, tachycardia, and a fever of 102.8°F. CT scan of the head and abdomen and chest x-ray revealed no significant findings. Empiric treatment with ampicillin, vancomycin, acyclovir, and ceftriaxone was initiated after two failed attempts at lumbar puncture, resulting in the improvement of all symptoms except for altered mental status within 24 h. Analysis of CSF, obtained via a successful subsequent lumbar puncture, was negative for microorganisms. The patient was labeled as a case of TMP-SMX-induced aseptic meningitis (TSIAM) due to the recent use of the drug for UTI. All the antibiotics and antivirals were discontinued, and all his symptoms resolved within 5 days of presentation. TSIAM is a diagnosis of exclusion, and a low threshold of suspicion should be maintained when CSF microscopy and culture show no microorganisms. This case illustrates the significance of prompt recognition of TSIAM and highlights the importance of thorough history-taking in preventing complications associated with drug-induced aseptic meningitis, thereby improving patient outcomes.