Clinical utility of an LC-MS/MS seizure panel for common drugs involved in drug-induced seizures.
BACKGROUND
Approximately 6% of new-onset seizures are drug-related, but there is currently no reliable way to determine if a seizure is drug-induced. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is a powerful tool that allows simultaneous detection of numerous analytes of diverse chemical nature in patient samples. This allows a single analysis to incorporate many compounds relevant to a particular clinical presentation, such as suspected drug-induced seizures. We investigated whether results from a seizure panel using LC-MS/MS could affect patient care.


METHODS
We developed a semiquantitative LC-MS/MS assay to detect 12 chemically diverse drugs implicated in drug-related seizures. We collected leftover serum and plasma samples from patients who had seized, performed solid-phase extraction, and analyzed the samples using a hybrid triple quadrupole/linear ion trap mass spectrometer. After assembling a team of medical and toxicology experts, we developed and used a scoring system to determine whether the results of the seizure panel would have affected patient treatment in each case where a drug was detected.


RESULTS
In an analysis of 157 samples from patients who seized, 17 (11%) were found to be positive for a drug on the seizure panel. The team of experts determined that the test results probably or definitely would have affected treatment in 7 (41%) of these cases.


CONCLUSIONS
A test that detects the presence of drugs implicated in drug-induced seizures can help physicians determine if an unexplained seizure is drug-related and thus potentially better direct patient care. Additionally, LC-MS/MS is an effective tool for answering clinically driven questions.
Drees
Julia C
JC
Department of Laboratory Medicine, University of California-San Francisco, San Francisco, CA, USA.
Stone
Judy A
JA
Olson
Kent R
KR
Meier
Kathryn H
KH
Gelb
Alan M
AM
Wu
Alan H B
AH
D000328:Adult; D000368:Aged; D002853:Chromatography, Liquid; D016903:Drug Monitoring; D064420:Drug-Related Side Effects and Adverse Reactions; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D004364:Pharmaceutical Preparations / Q000097:blood*; D012640:Seizures / Q000097:blood* / Q000139:chemically induced*; D012680:Sensitivity and Specificity; D052616:Solid Phase Extraction; D053719:Tandem Mass Spectrometry
D004364:Pharmaceutical Preparations