Abstract
A case of suspected myoclonus in a 2-year-old male after multiple doses of meperidine given intramuscularly is reported. Meperidine, as well as many other drugs possess serotonin reuptake inhibitor activity and in this report the interaction between several drugs with similar activity may have contributed to the adverse effects seen. It is theorized that since the clinical presentation of myoclonus is included in case reports of serotonin syndrome in the literature this adverse reaction may in fact be part of this syndrome. It is proposed that the name serotonin syndrome may mislead investigators and it may be better thought of as a progression of increasingly serious sequelae that may occur more frequently than clinicians realize. It is important for physicians and caregivers to educate themselves on the cumulative effects that serotonin like drugs like normeperidine may exhibit, especially in combination. In an acute setting when renal and hepatic function may be compromised or in the elderly or young we find that these populations may be especially at risk. In light of recent evidence on the prevalence of drug-drug interactions involving the cytochrome metabolic system it may be important to further investigate the clinical presentation of meperidine induced myoclonus and emphasize further the discontinuation of the use of the drug.