Rhabdomyolysis After Correction of Hyponatremia in Psychogenic Polydipsia Possibly Complicated by Ziprasidone

Rhabdomyolysis is a potentially lethal syndrome result-ing from the lysis of muscle fibers with leakage of po-tentially toxic cellular contents into the systemic circula-tion. It was first described in the victims of crush injury during the 1940–1941 bombing raids of World War II in London, England. Common etiological risk factors are di-verse including alcohol abuse, recent soft tissue compres-sion or trauma, seizure activity, drug abuse, hypothermia, sepsis, metabolic derangements, gangrene, connective tis-sue disorders, inherited myopathies, and burns. Rhabdomy-olysis was first associated with hyponatremia secondary to psychogenic polydipsia (PP) in 1979.1 Since then, only 27 such cases have been described.2-17 The final common path-way of rhabdomyolysis has been described as a distur-bance in the calcium homeostasis of the myocyte leading to cell breakdown and enzyme leakage to occur.12,13 PP has a prevalence varying between 6.2 % and 20 % in the severely psychiatrically disabled population, with se-vere hyponatremia developing in almost one-fourth of these patients. Patients with PP may present with increas-ing water seeking and water drinking, incidental hypona-tremia or hyposthenuria on laboratory testing, or requiring medical intervention for symptoms of water intoxication. With rapid correction of hyponatremia, serious neurologic complications like central pontine myelinosis, coma, or death can occur. Reports of non-neurologic complications from the correction of hyponatremia are scarce. Rhabdomyolysis with correction of hyponatremia sec-ondary to PP has been reported in only 2 previous cas