Rhabdomyolysis Following Trimethoprim-Sulfamethoxazole Therapy: A Case Report and Review of the Literature.

Background: Trimethoprim-Sulfamethoxazole (TMP-SMX) is a commonly used antibiotic for the treatment of several infections, such as urinary tract infections, respiratory infections, and in certain cases, septic arthritis. Rhabdomyolysis (RM) is very rare and less than 20 cases have been reported, so far, in the literature, in particular in immunocompromised patients. Here, we report a case of TMP-SMX-induced RM in an immunocompetent patient, adding to the limited data on this association.

Case presentation: A 53-year-old male patient with no prior medical history presented with septic arthritis and was initiated on TMP-SMX therapy. Within days, he developed muscle pain and weakness with laboratory tests revealing markedly elevated Creatine Kinase (CK) levels, consistent with rhabdomyolysis. Following the discontinuation of TMP-SMX, the patient's CK levels gradually decreased, and his symptoms resolved without further intervention.

Conclusion: To our knowledge, this is the sixth reported case of TMP-SMX-associated rhabdomyolysis in an immunocompetent patient. This case highlights the need for clinicians to consider the potential for rhabdomyolysis in patients receiving TMP-SMX, regardless of their immune status, and to recognize that prompt withdrawal of the drug is critical for patient recovery.