A Sudden Fluctuation in Creatinine Kinase: Water Intoxication and Rhabdomyolysis

Water intoxication often causes hyponatremia. Acute hyponatremia and its rapid correction have been reported to cause rhabdomyolysis. However, little is known about the clinical course of water-intoxication-related rhabdomyolysis. We report a case of self-induced water intoxication resulting in rhabdomyolysis, in which serum creatinine kinase surged rapidly. The appropriate selection of fluid therapy was difficult because of the differences in the standard treatments for each complication. Water restriction is used to treat water intoxication, while the opposite, fluid resuscitation, is used to treat rhabdomyolysis. Close monitoring of serum creatinine kinase was useful in determining fluid management in such a situation.