Withdrawal syndromes following administration of sedative and analgesic infusions represent a significant morbidity that is described increasingly in the pediatric critical care literature. However, there are few descriptions of pentobarbital withdrawal symptoms and their treatment in the pediatric population. We describe an infant receiving multiple sedative and analgesic medications, including pentobarbital, who was resistant to our institution's standard weaning protocol, but whose severe withdrawal symptoms responded dramatically to phenobarbital loading and maintenance. [ABSTRACT FROM AUTHOR]