The United States is experiencing an epidemic of bath salts and synthetic cannaboid abuse, but determining exactly the causative agent when patients turn up overdosed in emergency settings remains a daunting challenge. For example, despite being structurally similar to amphetamines, bath salts generally are not detectable by amphetamine immunoassays.

In a detailed webinar, “Investigating Negative Drug Test Results in the Suspected Overdose Patient,” toxicology expert Amitava Dasgupta, PhD, DABCC, professor of pathology and laboratory medicine at the University of Texas-Houston Medical School, will provide participants with practical problem-solving tips when initial toxicology results are negative but a patient obviously has ingested some type ofdrug or substance.

Dasgupta will describe at least seven case studies involving false-negative results that, upon further investigation, confirmed patients’ overdoses. “It’s important to recognize that a negative toxicology report does not necessarily mean that there are no drugs-of-abuse present in the patient’s urine,” according to a preview of the webinar. “Many drugs, including opioids like oxycodone, can escape detection by opiate immunoassays because the antibody targets—morphine and oxycodone—have poor cross-reactivity.” Dasgupta will discuss both specialized immunoassays and chromatographic techniques that can improve drug detection.

As director of clinical chemistry, toxicology, and point of care services at Memorial Hermann-Texas Medical Center in Houston, Dasgupta has written at least 198 papers for peer-reviewed journals, as well as three consumer health books and two reference books on toxicology, including Accurate Results in the Clinical Laboratory: A Guide to Error Detection and Correction. In 2009, he received the Irvine Sunshine Award from the International Association of Therapeutic Drug Monitoring and Clinical Toxicology for his outstanding contributions in clinical toxicology research.