Rhabdomyolysis associated with olanzapine treatment in a child with Autism.

Children with autism often display difficult behaviors including tantrums, extreme irritability, and physical aggression. There is emerging evidence that olanzapine is useful in decreasing these disruptive behaviors. The most common adverse effects are weight gain and short-term sedation. On the other hand, olanzapine rarely causes rhabdomyolysis. We report a case with rhabdomyolysis in an autistic child just after 2 doses of olanzapine treatment. Initial creatine kinase value was 30,690 IU/L (range, 5-130 U/L), and rhabdomyolysis resolved with hydration and alkalinization over 7 days. Monitoring serum creatine kinase levels may be useful in pediatric cases after initiation of olanzapine treatment.