Contributed by Shaymaa Hegazy, MD, MSc, Andrew Freeman, MD and Kenichi Tamama, MD, PhD DIAGNOSIS
LSD Overdose
DISCUSSION
This patient presented with agitation and altered mental status requiring multiple taser shots by the police. He continued to be combative and required intubation. His initial lab results were notable for elevated CPK and high-normal creatinine. The patient's elevated CPK may be the result of the electrical taser shocks the patient received. An association has been reported between taser shocks and the development of rhabdomyolysis and AKI, even though the thermal and electrical power produced by the taser does not trigger the release of intracellular myoglobin and CPK (1).
The patient's initial clinical diagnosis was a stimulant overdose, most likely due to either amphetamines or novel psychoactive substances (NPS) such as synthetic cathinones or cannabinoids. The initial immunoassay urine drug screen demonstrated unconfirmed positive results of Benzodiazepine but was negative for amphetamine.
Based on these results, the clinical team suspected a synthetic cathinone or cannabinoid overdose not covered by urine drug screening immunoassay. This result fits with the patient-reported history and initial treatment.
The patient's urine was further analyzed by LC-qTof/MS, which revealed a possible LSD metabolite (2-oxo-hydroxy metabolite) in a low concentration. His psychotic behavior with an altered mental status could be explained by LSD usage.
Interestingly, LSD can be ingested safely under controlled measures. Some research groups reported that ingestion of moderate dosages (50-200 µg) of LSD can be tolerated but can still cause mild alterations in vital signs (2,3,4). Other studies reported that LSD dosage of (75-150 µg) would alter the level of consciousness with psychotic effects (5).
Nevertheless, fatalities have also been reported after LSD intoxication due to dangerous and bizarre behaviors such as walking in the middle of a busy highway, attempting to climb rocks, swimming, or other activities that easily endanger patient lives (3).
FDA-approved LSD immunoassay kits (e.g., Siemens EMIT-II Plus LSD kit) are commercially available. These kits would allow for a rapid detection of LSD abuse by the clinical laboratories; however, most of the clinical toxicology laboratories including ours in the US do not use them because of the low prevalence of LSD abuse (6).
Detection of LSD in body fluids, including urine, is very challenging because of the low concentrations of LSD and its metabolites in the body fluids. Bocxlaer et al. reported that a few hours after the ingestion of a moderate dose (150 µg) of LSD, the plasma and urine concentrations of LSD would be at the sub ng/mL level (7). And that is why the LSD cutoff level is set to be 0.5 ng/mL in the EMIT-II kit.
In this case, an LSD metabolite (2-oxo-hydroxy metabolite) was tentatively identified by the non-targeted comprehensive drug screening with LC-qTof/MS, hybrid high-resolution mass spectrometry that can provide the molecular mass information of both precursor and product ions with an accuracy of 0.001 atomic mass units. LC-qTof/MS can make a presumptive compound identification based on the retention time and exact molecular formula even when the reference materials of these compounds and metabolites are not accessible (8,9,10).
One caveat of 2-oxo-hydroxy metabolite identification was its small peak with only one out of three ion fragments match, lowering our confidence level of the compound identification. In such a case, it is very important to correlate the results with the patient's clinical history.
Acknowledgments
The authors would like to thank Dr. Abesamis for his valuable suggestions on the manuscript.
REFERENCES
Contributed by Shaymaa Hegazy, MD, MSc, Andrew Freeman, MD and Kenichi Tamama, MD, PhD
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