Case Presentation: A 33-year-old male with a history of HIV, bipolar disorder and polysubstance abuse presented to the ED with one day of severe pain in his lower back and bilateral thighs. He described the pain as sharp and fiery, with radiation from the lower back to his knees bilaterally. Further history revealed that the patient smoked a significant amount of methamphetamine around four days prior to the onset of symptoms. This was followed by ‘partying’ for two days, involving sleep deprivation and sexual intercourse repeatedly for several hours at a time. He denied any other form of physical exertion within this time frame. On admission, vital signs included heart rate 106 beats/min, blood pressure 108/70 mmHg, respiratory rate 12, and temp of 97.8F. Pertinent physical exam findings included tenderness to palpation of the lower back and thighs, with reproducible pain on bending forward and on lifting the legs against gravity. Serum chemistry studies revealed an elevated creatine kinase at 34,496 U/L (reference range 30-200) with normal BUN and creatinine levels. Urine studies showed toxicology positive for amphetamines, along with small blood in urine. The patient’s clinical picture was consistent with rhabdomyolysis, likely secondary to severe exertional activity after stimulant use. The patient was treated with aggressive intravenous hydration with lactated ringer’s solution. Pain was managed with oral acetaminophen as needed. He was discharged on day three of hospital stay with a creatine kinase of 3712 U/L and complete resolution of symptoms.

Discussion: Rhabdomyolysis is a clinical condition characterized by acute skeletal muscle breakdown leading to muscle enzymatic components being released into bloodstream causing systemic complications, most commonly elevated creatine kinase, acute kidney injury and pain. There are many potential causes of rhabdomyolysis, including intense muscle activity, prolonged immobilization, drugs/toxins and inherited myopathies. Additionally, hyperkinetic states such as seizures, delirium tremens and amphetamine overdose have been known to result in rhabdomyolysis. Our case demonstrates a unique combination of factors leading up to rhadomyolysis, namely methamphetamine use followed by intense sexual activity.

Conclusions: Rhabdomyolysis after amphetamine use is usually tied to the users participating in rave parties, which involve continuous dancing in a warm and crowded environment, often ignoring thirst and fatigue. This precipitates exertional hyperthermia, dehydration and muscle injury, resulting in rhabdomyolysis. This case highlights sexual intercourse as an alternate mode of exertional activity resulting in a similar presentation.