B-317 Detection of bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate (BTMPS) throughout the United States in healthcare patient urine samples

Background Bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate (BTMPS, Tinuvin 770) is a synthetically manufactured hindered amine light stabilizer used in plastics manufacturing with no approved application for human consumption. Since mid-2024, BTMPS has been identified as an adulterant in the illicit drug supply. It is often detected in conjunction with new psychoactive substances (NPS), illicitly-manufactured fentanyl and xylazine; however, it has also been reported in combination with other substances as well, including methamphetamine and cocaine. Although studies of BTMPS effects on humans are limited, animal studies show that it is an active L-type calcium channel blocker that may be associated with cardiotoxicity, reproductive defects and skin irritation, among other local and systemic effects. Interestingly, BTMPS has also shown activity on nicotinic receptors in rats; the impact in humans is still unknown. Health care providers and laboratories should be aware of the emergence of BTMPS as an adulterant in the drug supply and its potential risks. Methods Urine samples collected from outpatient healthcare clinics across the United States were received by the laboratory with a medically necessary request to perform definitive testing between 12/10/2024 and 2/15/2025. Individuals providing specimens for testing had diagnoses related to chronic pain, opioid and/or substance use disorder, or mental illness. An LC-MS/MS analysis was performed on specimens and included definitive testing for BTMPS, as well as all other substances requested by the reporting provider. Prior to analysis of results, data was aggregated with PHI removed in concordance with an IRB approved protocol (Pearl IRB #AG-08-01v2.0). Co-positivity and demographic information were evaluated and summarized. Results Between 12/10/2024 - 2/15/2025, 141,623 urine specimens were received from 47 states with a request to perform definitive testing inclusive of BTMPS. BTMPS was detected in 89 (0.063%) specimens at a cutoff of 20 ng/mL. Specimens with positive findings originated from 17 unique states. When BTMPS was detected, the primary (>25%) co-detected compounds and/or drug classes included: fentanyl/norfentanyl: (92%) (samples tested: 85, detected: 78); xylazine/4-hydroxyxylazine: 84% (samples tested: 89, detected: 75); methaone/EDDP 61% (samples tested: 84, detected: 51); fluorofentanyl/metabolites 57% (samples tested: 88, detected: 50); cocaine/benzoylecgonine 50% (samples tested: 84, detected: 42); medetomidine/3-OH-medetomidine 33% (samples tested: 89, detected: 29), 6-monoacetylmorphine 33% (samples tested: 84, detected: 28); bromazolam/a-OH-bromazolam 30% (samples tested: 83, detected: 25); and 8-aminoclonazolam 29% (samples tested: 83, detected: 24). Conclusion BTMPS is an emerging, high-risk substance in the drug supply that needs to be monitored. This compound is particularly concerning given its toxic properties and unknown pharmacological profile in humans. Recent identification within the drug supply can create increased risk for adverse events. Fentanyl and/or other illicit substances were identified in a vast majority of samples; research is ongoing to further elucidate concomitant use profiles. As the illicit drug supply continues to see introduction of novel and sometimes unexpected adulterants, ongoing NPS panel development provides critical insight into the presence of potentially toxic substances such as BTMPS that can help clinicians provide the best possible care for patients.