Wastewater surveillance of high risk substances in Southern Nevada: Sucralose normalization to translate data for potential public health action

The COVID-19 pandemic highlighted the value of wastewater surveillance in providing unbiased assessments of incidence/prevalence for infectious disease targets, ultimately leading to the development of local, state, and national programs across the United States. To address the growing epidemic of drug abuse, there have been calls to extend these programs to high risk substances (HRS) and metabolites, while leveraging the experience gained during the pandemic and from ongoing efforts in other countries. This study further advances the science of wastewater surveillance for HRS by (1) highlighting analytical and sewer transport considerations, (2) proposing sucralose normalization to adjust for varying human urine/fecal load and confounded population estimates (e.g., high tourism areas), and (3) characterizing temporal and geographic trends in HRS use. This one-year study across eight sewersheds in Southern Nevada (208 total samples) monitored concentrations of 17 pharmaceuticals and personal care products (PPCPs) and 22 HRS and metabolites, including natural, semi-synthetic, and synthetic opioids. The data indicated a ∼200 % increase in heroin and methamphetamine use since 2010, a stark increase in fentanyl consumption beginning in October 2022, and statistically significant differences in HRS consumption patterns between sewersheds and on certain dates. Notably, the latter outcome highlights the potential for wastewater surveillance data to be strategically translated into public health action to reduce and/or more rapidly respond to overdoses.

Association of Urine Fentanyl Concentration With Severity of Opioid Withdrawal Among Patients Presenting to the Emergency Department

BACKGROUND AND AIMS

Fentanyl is involved in most US drug overdose deaths and its use can complicate opioid withdrawal management. Clinical applications of quantitative urine fentanyl testing have not been demonstrated previously. The aim of this study was to determine whether urine fentanyl concentration is associated with severity of opioid withdrawal.

DESIGN

This is a retrospective cross-sectional study.

SETTING

This study was conducted in 3 emergency departments in an urban, academic health system from January 1, 2020, to December 31, 2021.

PARTICIPANTS

This study included patients with opioid use disorder, detectable urine fentanyl or norfentanyl, and Clinical Opiate Withdrawal Scale (COWS) recorded within 6 hours of urine drug testing.

MEASUREMENTS

The primary exposure was urine fentanyl concentration stratified as high (>400 ng/mL), medium (40-399 ng/mL), or low (<40 ng/mL). The primary outcome was opioid withdrawal severity measured with COWS within 6 hours before or after urine specimen collection. We used a generalized linear model with γ distribution and log-link function to estimate the adjusted association between COWS and the exposures.

FINDINGS

For the 1127 patients in our sample, the mean age (SD) was 40.0 (10.7), 384 (34.1%) identified as female, 332 (29.5%) reported their race/ethnicity as non-Hispanic Black, and 658 (58.4%) reported their race/ethnicity as non-Hispanic White. For patients with high urine fentanyl concentrations, the adjusted mean COWS (95% confidence interval) was 4.4 (3.9-4.8) compared with 5.5 (5.1-6.0) among those with medium and 7.7 (6.8-8.7) among those with low fentanyl concentrations.

CONCLUSIONS

Lower urine fentanyl concentration was associated with more severe opioid withdrawal, suggesting potential clinical applications for quantitative urine measurements in evolving approaches to fentanyl withdrawal management.

Ritalinic acid in urine: Impact of age and dose

Objectives

The objective of this work was to study the results of urine drug testing for ritalinic acid (RA), the major urinary metabolite of methylphenidate (MP) (e.g., Ritalin®). The impact of age from 4 to 65 years old and older on median levels of RA was investigated as well as potential variations in pH, specific gravity and creatinine content of the patient urine samples.

Design and Methods

Samples from patients who were 1) prescribed MP and found to be positive for RA, 2) prescribed MP but found to be negative for RA and 3) not prescribed MP but tested positive for RA were examined by liquid chromatography – mass spectrometry/mass spectrometry (LC-MS/MS) for RA concentration. The levels of RA were examined for median and average levels and further normalized and transformed to reveal a near gaussian distribution.

Results

Over 20,000 samples from patients who were prescribed MP were examined for this work. Analysis of these data for a subset of patients prescribed MP and testing positive for RA revealed statistically different median values of RA for school age patients of 6 years old through 17 years old from adult patients 18 through 64 years old. Another 6751 samples were positive for RA without a prescription but were not included in the overall assessment of these data.

Conclusions

While not clear as to the reason, these data indicate that school age children under the age of 18 have much higher levels of RA than adult patients. These results can be used to estimate “normal” levels of RA in these chronically dosed populations.

Performance of Two Fentanyl Immunoassays against a Liquid Chromatography-Tandem Mass Spectrometry Method

Rapid and automated fentanyl screening assays are in need due to the prevalence of fentanyl abuse. In the present study, we evaluated the clinical performance of two FDA-cleared automated fentanyl immunoassays, the Immunalysis SEFRIA fentanyl assay and the ARK fentanyl assay. Liquid chromatography-tandem mass spectrometry (LC-MS-MS) was used as a gold standard. Two groups of urine specimens were tested, including 225 specimens from patients presenting to the emergency department (ED) for whom urine drugs of abuse screens were ordered and 57 specimens from patients in chronic pain management programs. The SEFRIA assay generated higher assay imprecision than ARK assay (intraday CV%, 7.15 vs. 4.7%; interday CV%, 6.6 vs. 5.3%). Clinical sensitivity and specificity for detection of fentanyl exposure were 100 and 96% for the ARK assay and 95 and 80% for the SEFRIA assay. An 'auto-repeating' issue was observed for some validation specimens flagged with high absorbance values (OD > 3.0), generating false repeat results. The frequency of auto-repeating was lower in the ARK assay than SEFRIA (0.7 vs. 15.5%). Auto-repeating occurred for only previously frozen specimens in the ARK assay, but 9% of fresh specimens were also flagged and repeated in the SEFRIA assay. Positive predictive value (PPV) of the ARK assay was 73% in the ED population and 67% in the non-ED populations. The concentrations of fentanyl and norfentanyl were higher in specimens from ED patients than patients from pain management programs. High prevalence of morphine, methamphetamine, benzoylecgonine and 6-MAM was observed in specimens positive for fentanyl in both populations.

A Rapid LC-MS-MS Method for the Quantitation of Antiepileptic Drugs in Urine

Epilepsy is a common neurologic disease that requires treatment with one or more medications. Due to the polypharmaceutical treatments, potential side effects, and drug-drug interactions associated with these medications, therapeutic drug monitoring is important. Therapeutic drug monitoring is typically performed in blood due to established clinical ranges. While blood provides the benefit of determining clinical ranges, urine requires a less invasive collection method, which is attractive for medication monitoring. As urine does not typically have established clinical ranges, it has not become a preferred specimen for monitoring medication adherence. Thus, large urine clinical data sets are rarely published, making method development that addresses reasonable concentration ranges difficult. An initial method developed and validated in-house utilized a universal analytical range of 50-5,000 ng/mL for all antiepileptic drugs and metabolites of interest in this work, namely carbamazepine, carbamazepine-10,11-epoxide, eslicarbazepine, lamotrigine, levetiracetam, oxcarbazepine, phenytoin, 4-hydroxyphenytoin, and topiramate. This upper limit of the analytical range was too low leading to a repeat rate of 11.59% due to concentrations >5,000 ng/mL. Therefore, a new, fast liquid chromatography-tandem mass spectrometry (LC-MS-MS) method with a run time under 4 minutes was developed and validated for the simultaneous quantification of the previously mentioned nine antiepileptic drugs and their metabolites. Urine samples were prepared by solid-phase extraction and analyzed using a Phenomenex Phenyl-Hexyl column with an Agilent 6460 LC-MS-MS instrument system. During method development and validation, the analytical range was optimized for each drug to reduce repeat analysis due to concentrations above the linear range and for carryover. This reduced the average daily repeat rate for antiepileptic testing from 11.59% to 4.82%. After validation, this method was used to test and analyze patient specimens over the course of approximately one year. The resulting concentration data were curated to eliminate specimens that could indicate an individual was noncompliant with their therapy (i.e., positive for illicit drugs) and yielded between 20 and 1,700 concentration points from the patient specimens, depending on the analyte. The resulting raw quantitative urine data set is presented as preliminary reference ranges to assist with interpreting urine drug concentrations for the nine aforementioned antiepileptic medications and metabolites.

Development and Clinical Validation of a Sensitive Lateral Flow Assay for Rapid Urine Fentanyl Screening in the Emergency Department

BACKGROUND

Rapid identification of fentanyl at the point-of-care is critical. Urine fentanyl concentrations in overdose cases start at single-digit nanograms per milliliter. No fentanyl point-of-care assay with a cutoff at single-digit nanograms per milliliter is available.

METHODS

A competitive lateral flow assay (LFA) was developed using gold nanoparticles and optimized for rapid screening of fentanyl in 5 minutes. Urine samples from 2 cohorts of emergency department (ED) patients were tested using the LFA and LC-MS/MS. The 2 cohorts consisted of 218 consecutive ED patients with urine drug-of-abuse screen orders and 7 ED patients with clinically suspected fentanyl overdose, respectively.

RESULTS

The LFA detected fentanyl (≥1 ng/mL) and the major metabolite norfentanyl (≥10 ng/mL) with high precision. There was no cross-reactivity with amphetamine, cocaine, morphine, tetrahydrocannabinol, methadone, buprenorphine, naloxone, and acetaminophen at 1000 ng/mL and 0.03%, 0.4%, and 0.05% cross-reactivity with carfentanil, risperidone, and 9-hydroxyrisperidone, respectively. In 218 consecutive ED patients, the prevalence of cases with fentanyl ≥1 ng/mL or norfentanyl ≥10 ng/mL was 5.5%. The clinical sensitivity and specificity of the LFA were 100% (95% CI, 75.8-100%) and 99.5% (95% CI, 97.3-99.9%), respectively. The positive and negative predictive values were 92.3% (95% CI, 66.7-98.6%) and 100% (95% CI, 98.2-100%), respectively. The concordance between the LFA and LC-MS/MS was 100% in the 7 suspected fentanyl overdose cases (5 positive, 2 negative).

CONCLUSIONS

The LFA can detect fentanyl and norfentanyl with high clinical sensitivity and specificity in the ED population with rapid fentanyl screening needs.

Fatal Transdermal Fentanyl Patch Overdose in a Child

A previously healthy three-year-old girl was brought into the emergency department by ambulance after being found unresponsive with a family member’s fentanyl patch found adherent to her lower back. A head CT scan showed global cerebral edema and the patient progressed to brain death. An initial standard urine drug screen was negative for opiates, however, subsequent specific urine assay testing was found to be positive for fentanyl and norfentanyl. This case highlights the dangers of not properly disposing of used fentanyl patches as they may still contain enough fentanyl to cause respiratory failure and subsequent unintentional death in children. Prescribing physicians and pediatricians should advise care providers that fentanyl patches should be carefully stored, monitored, and disposed of properly in order to prevent accidental exposure to the pediatric population. Furthermore, synthetic opiates such as fentanyl will not read as positive on routine urine drug screens and will require specific urine assays.

Commentary. Fentanyl-related death and the underreporting risk

Novel synthetic opioid overdose deaths have been rising largely worldwide as a result of fentanyl adulteration in the illegal drug supply. Interpretation of post mortem analytical results concerning fentanyl can be challenging in particular due to redistribution phenomena. Lacking of resources, infrastructures and expertise to perform forensic toxicological investigation when an unknown drug or complex mixture of drugs is suspected can affect failure in exactly reporting cause in drug related death. Public safety and public health entities are called working together to enhance the timeliness and accuracy of the analytical characterization and toxicology testing of novel synthetic opioids.

Zolpidem and Zolpidem Carboxylic Acid Results from Medication Monitoring

Zolpidem (Ambien®) is one of the "Z" drugs often used to improve sleep in older patients and those suffering from insomnia. Schwope, D.M., DePriest, A., Black, D.L., Caplan, Y.H., Cone, E.J., Heltsley, R. (2014) Determing zolpidem compliance: urinary metabolite detection and prevalence in chronic pain patients . Journal of Analytical Toxicology, 38, 513-518 reported that zolpidem in urine is not very prevalent being present <23% of the time in patient urine while the major metabolite, zolpidem 4-phenyl carboxylic acid (ZCA), is much more prevalent in urine with positive rates as high as 50% of the patient samples reviewed. Results from patient testing over a year's time are in agreement with the reported zolpidem results. However, the data observed herein for ZCA are not consistent with the earlier report. These data suggest that monitoring ZCA may result in even higher levels of positivity. Further, while the Food and Drug Administration has pointed out that female dosing should be half that given to males, results of this population testing indicate that the majority of patients (83% male and 73% female) receive 10 mg/day or 12.5 mg/day for Ambien CR® with females demonstrating statistically significantly higher levels of ZCA albeit zolpidem levels are not statistically significantly different between men and women. Estimates of patient positivity are dependent upon the value of the limit of quantification (LOQ) as demonstrated by the zolpidem results herein (LOQ = 50 ng/mL vs. 4 ng/mL). However, even with a much higher LOQ of 50 ng/mL for ZCA in this work, the positivity from ZCA results is significantly higher (e.g., 64.8%) than reported earlier (50.3%). Nevertheless, these data support the addition of ZCA for monitoring zolpidem in urine.

Characteristics of opioid-maintained clients smoking fentanyl patches: The importance of confirmatory drug analysis illustrated by a case series and mini-review

The increase in opioid prescribing in many European countries over the last decade has raised concerns about associated diversion, overdose, and mortality. Fentanyl is one of these synthetic opioids that is typically prescribed as a transdermal patch for pain that requires continuous pain relief and has been the focus of investigation due to reports of overdose and death. We report a case series of 14 drug addiction treatment entrants, who entered treatment in a service located in the region of Southern Denmark from August 2015 to December 2015 for smoking fentanyl patches. Clients presented with difficulties breathing and pains in the lungs. The clients had a history of past opioid use, including heroin. Relapses resulted in treatment disengagement. Immunoassays for fentanyl were used in the service. In some cases, false negative results occurred. Clients' urine samples were subsequently analysed in a collaborating laboratory. Seven clients tested positive for fentanyl. One client was positive for both fentanyl and heroin. Analyses were also positive for other opioids and metabolites in 6 clients, predominantly codeine and oxycodone. Results from confirmatory analysis contributed to clearer insights into clients' drug histories, which facilitated personalised care plans consisting of opioid agonist therapy informed by confirmed drug use. In Denmark, prescription levels of fentanyl are high, which has been accompanied by observations of diversion and smoking in a smaller population. In addition to revision of inappropriate prescribing to reduce diversion, we recommend increased reliance upon confirmatory drug analysis in the addiction treatment sector in Denmark.

Analytical Considerations When Developing an LC-MS/MS Method for More than 30 Analytes

BACKGROUND

While validation of analytical (LC-MS/MS) methods has been documented in any number of articles and reference texts, the optimal design and subsequent validation of a method for over 30 analytes presents special challenges. Conventional approaches to calibration curves, controls, and run time are not tenable in such methods. This report details the practical aspects of designing and implementing such a method in accordance with College of American Pathologists validation criteria.

METHODS

Conventional criteria were followed in the design and validation of a method for 34 analytes and 15 internal standards by LC-MS/MS. These criteria are laid out in a standard operating procedure, which is followed without exception and is consistent with College of American Pathologists criteria.

RESULTS

The method presented herein provides quality results and accurate medication monitoring. The method was optimized to negate interferences (both from within the method and from potential concomitant compounds), increase throughput, and provide reproducible quality quantification over relevant analyte concentrations ranges.

CONCLUSIONS

The method was designed primarily with quality and accurate medication monitoring in mind. The method achieves these goals by use of novel approaches to calibration curves and controls that both improve performance and minimize risk (financial and operational). As automation and LC-MS/MS equipment continue to improve, it is expected that more methods like this one will be developed.