Inadvertent Intrathecal Administration of Vincristine.

Background: Vincristine is a vesicant drug which is normally given intravenously. Intrathecal administration of vincristine is a therapeutic misadventure, causing chemical leptomeningitis and focal ventriculitis. While 55 cases of intrathecal vincristine administration have been reported worldwide, only 32 cases have been documented in the literature, 13 have been reported to the FDA Med Watch, and many more cases are believed to be unreported. Of the documented cases, 84.3% resulted in death and 15.6% of those who survived had serious neurological consequences such as quadriplegia and paraplegia.

Methods: The Research on Adverse Events and Reports (RADAR) project conducted a review of literature published between 1968 and June 2006. Sources included Med Watch reports, published abstracts and journal articles, online newsletters, and letters from pharmacists.

Findings: The reports reviewed showed that intrathecal administration of vincristine occurred most often because of inadequate communication between pharmacy and medical staff (22 of 32 cases; 68.7%). In these cases, the pharmacy mistakenly delivered vincristine syringes together with syringes containing intrathecal medications and physicians or nurses wrongly administered vincristine intrathecally. Pharmacy error alone, such as the mislabeling of syringes, accounted for 6 of 32 cases of intrathecal administration of vincristine (18.7%) while physician/nurse error alone (failure to read syringe labeling or check physician’s orders) accounted for 4 of 32 cases (12.5%).

Conclusions: Since vincristine is lethal when given intrathecally, its administration should be executed with the precautionary measures employed with other potentially lethal substances, such as blood products. Carefully reviewing physician orders before drug administration and dispensing vincristine in syringes incompatible with spinal needles can also curb fatal error. Other preventive measures include properly labeling vincristine syringes for intravenous use only and diluting vincristine in intravenous mini-infusion bags.