Pregabalin- and azithromycin-induced rhabdomyolysis with purpura: An unrecognized interaction: A case report

INTRODUCTION: Rhabdomyolysis associated with the use of pregabalin or azithromycin has been demonstrated to be a rare but potentially life-threatening adverse event. Here, we report an extremely rare case of rhabdomyolysis with purpura in a patient who had used pregabalin and azithromycin. PRESENTATION OF CASE: We present the case of a 75-year-old woman with a history of fibromyalgia who was admitted with mild limb weakness and lower abdominal purpura. She was prescribed pregabalin (75 mg, twice daily) for almost 3 months to treat chronic back pain. Her medical history revealed that 3 days before admission, she began experiencing acute bronchitis and was treated with a single dose of azithromycin (500 mg). She had developed rapid onset severe myalgia, mild whole body edema, muscle weakness leading to gait instability, abdominal purpura and tender purpura on the lower extremities. Laboratory values included a white blood cell count of 25,400/mL and a creatinine phosphokinase (CPK) concentration of 1250 IU/L. Based on these findings and the patient’s clinical history, a diagnosis of pregabalin- and azithromycin-induced rhabdomyolysis was made. DISCUSSION: The long-term use of pregabalin and the initiation azithromycin therapy followed by a rapid onset of rhabdomyolysis is indicative of a drug interaction between pregabalin and azithromycin. CONCLUSION: We report an extremely rare case of rhabdomyolysis with purpura caused by a drug interaction between pregabalin and azithromycin. However, the mechanisms of the interactions between azithromycin on the pregabalin are still unknown.