Rhabdomyolysis Occurring After Use of Cocaine Contaminated With Fentanyl Causing Bilateral Brachial Plexopathy.

Background: Rhabdomyolysis is caused by muscle overuse, trauma, prolonged immobilization, drugs, or toxins. As rhabdomyolysis progresses, swelling and edema can compress surrounding structures. Few cases of the phenomenon occurring as a sequela of substance use have been described. Case Presentation: We present a 68-year-old male patient with rhabdomyolysis following use of crack cocaine contaminated with fentanyl. The patient had 0/5 strength bilaterally and bilateral absent reflexes in the upper extremities. Sensation was markedly decreased, as he was unable to feel temperature, pinprick sensation, or general touch. Creatine phosphokinase level was elevated at 21,292 IU/L. On magnetic resonance imaging, there was abnormal signal in the lower neck bilaterally. It is presumed that muscular edema resulted in partial narrowing of the thoracic outlet bilaterally with corresponding mass effect on the traversing brachial plexus. Conclusions: This is the seventh case of brachial plexopathy secondary to rhabdomyolysis precipitated by opioid use that has been reported in the literature. Prospective studies should examine treatment for this condition.