To evaluate trends and toxicity of methylphenidate abuse in pre-teens and adolescents reported to poison centers.

The 1993–1999 American Association of Poison Control Centers Toxic Exposure Surveillance System was queried for methylphenidate abuse cases in children aged 10 through 19 years that were followed to known outcome. Main outcome measures included number of cases annually, toxicity, management site, and coded medical outcome.

Of 759 cases, 42.7% involved 10-through 14-year-olds. For the 530 (70.0%) cases involving methylphenidate only, the frequency increased sevenfold from 1993 to 1999. Of 570 patients (75.1%) managed in a health care facility, 398 were discharged from the emergency department and 172 were admitted. Symptoms occurred more commonly in exposures involving coingestants (84.3%) than in methylphenidate-only exposures (71.1%). The most common symptoms in adolescents with methylphenidate only were tachycardia (31.7%), agitation/irritability (25.7%), and hypertension (11.5%). Outcomes were no effect in 189 cases (24.9%) and mild, moderate, and severe in 318 (41.9%), 245 (32.3%), and 7 (0.9%) patients, respectively.

Poison center data demonstrate increasing frequency of methylphenidate abuse. While the majority of adolescents experienced clinical effects and were managed in a health care facility, outcomes were good, especially in cases involving methylphenidate only.