Addressing discordant quantitative urine buprenorphine and norbuprenorphine levels: Case examples in opioid use disorder

Association of Patients' Direct Addition of Buprenorphine to Urine Drug Test Specimens With Clinical Factors in Opioid Use Disorder

Importance

The direct addition of buprenorphine to urine drug test specimens to mimic results suggestive of adherence is a clinically significant result, yet little is known about the phenomenon.

Objective

To characterize factors associated with the direct addition of buprenorphine to urine specimens among patients prescribed buprenorphine for opioid use disorder.

Design, Setting, and Participants

This cross-sectional study of urine drug test specimens was conducted from January 1, 2017, to April 30, 2022, using a national database of urine drug test specimens ordered by clinicians from primary care, behavioral health, and substance use disorder treatment clinics. Urine specimens with quantitative norbuprenorphine and buprenorphine concentrations from patients with opioid use disorder currently prescribed buprenorphine were analyzed.

Exposures

Nonprescribed opioid or stimulant co-positive, clinical setting, collection year, census division, patient age, patient sex, and payor.

Main Outcomes and Measures

Norbuprenorphine to buprenorphine ratio less than 0.02 identified direct addition of buprenorphine. Unadjusted trends in co-positivity for stimulants and opioids were compared between specimens consistent with the direct addition of buprenorphine. Factors associated with the direct addition of buprenorphine were examined with generalized estimating equations.

Results

This study included 507 735 urine specimens from 58 476 patients. Of all specimens, 261 210 (51.4%) were obtained from male individuals, and 137 254 (37.7%) were from patients aged 25 to 34 years. Overall, 9546 (1.9%) specimens from 4550 (7.6%) patients were suggestive of the direct addition of buprenorphine. The annual prevalence decreased from 2.4% in 2017 to 1.2% in 2020. Opioid-positive with (adjusted odds ratio [aOR], 2.01; 95% CI, 1.85-2.18) and without (aOR, 2.02; 95% CI, 1.81-2.26) stimulant-positive specimens were associated with the direct addition of buprenorphine to specimens, while opioid-negative/stimulant-positive specimens were negatively associated (aOR, 0.78; 95% CI, 0.71-0.85). Specimens from patients aged 35 to 44 years (aOR, 1.59; 95% CI, 1.34-1.90) and primary care (aOR, 1.60; 95% CI, 1.44-1.79) were associated with the direct addition of buprenorphine. Differences by treatment setting decreased over time. Specimens from the South Atlantic census region had the highest association (aOR, 1.4; 95% CI, 1.25-1.56) and New England had the lowest association (aOR, 0.54; 95% CI, 0.46-0.65) with the direct addition of buprenorphine.

Conclusions and Relevance

In this cross-sectional study, the direct addition of buprenorphine to urine specimens was associated with other opioid positivity and being collected in primary care settings. The direct addition of buprenorphine to urine specimens is a clinically significant finding, and best practices specific for this phenomenon are needed.

Do buprenorphine doses and ratios matter in medication assisted treatment adherence?

Introduction

Buprenorphine (BUP), generally prescribed as buprenorphine/naloxone, is a key component of medication-assisted treatment (MAT) to manage opioid use disorder. Studies suggest higher doses of BUP increase treatment adherence. Routine urine drug screens (UDS) assist in monitoring MAT adherence via measurement of excreted BUP and its metabolite, norbuprenorphine (NBP). The clinical significance between BUP/NBP concentrations and their ratios for assessing adherence and substance use is not well-described.

Methods

We conducted a single-center, retrospective chart review of 195 clients age ≥18 years enrolled in a local MAT program from August 2017 to February 2021. Demographics, BUP doses, prescription history, and UDS results were collected. Participants were divided based on MAT adherence (<80% vs ≥80%) and median total daily dose (TDD) of BUP (≥16 mg vs <16 mg) in addition to pre- and post-COVID-19 cohorts.

Results

Median BUP/NBP urinary concentrations were significantly correlated with MAT adherence (P < .0001 for each) and a reduced percentage of positive UDS for opioids (P = .0004 and P < .0001, respectively) but not their ratios. Median TDD of BUP ≥16 mg (n = 126) vs <16 mg (n = 68) was not correlated with MAT adherence (P = .107) or incidence of nonprescription use (P = .117). A significantly higher incidence of UDS positive for opiates (P = .049) and alcohol (P = .035) was observed post-COVID-19.

Discussion

Clients appearing adherent to MAT who had higher concentrations of urinary BUP/NBP demonstrated a reduced incidence of opioid-positive UDS independent of the BUP dose prescribed. An increase in opioid- and alcohol-positive UDSs were observed during the COVID-19 pandemic.

Urinary Buprenorphine, Norbuprenorphine and Naloxone Concentrations and Ratios: Review and Potential Clinical Implications

OBJECTIVES

Treatment with medications for opioid use disorder such as buprenorphine improves patient morbidity and mortality as well as treatment adherence, an important component of patient care. Buprenorphine is combined with naloxone to reduce misuse; and, when taken sublingually, naloxone is poorly absorbed. Urine testing for buprenorphine is a common way to monitor adherence. Some patients who want to appear adherent may directly tamper with their urine by adding buprenorphine to their urine to allow for the detection without ingestion. Practitioners may rely upon the concentration of buprenorphine and the metabolite, norbuprenorphine, and utilize the ratio of metabolite to parent compound (norbuprenorphine:buprenorphine - N:B ratio) to discern possible evidence of tampering; however, there remains debate as to what specific ratio may signify this practice. Testing for naloxone may also help determine if urine tampering occurred as only low naloxone concentrations are found in the urine when taken by a sublingual route.

METHODS

To determine a reliable N:B ratio that may be used to identify possible urine tampering by adding parent drug directly to urine, we examined 136,605 urine samples for quantitative concentrations of buprenorphine and norbuprenorphine by LC-MS/MS performed at a commercial laboratory. After identifying abnormal ratios (<0.02), we then compared them with naloxone concentrations and specimen validity testing, other markers that may coincide with specimen tampering of this type.

RESULTS

Correlating urinary buprenorphine and norbuprenorphine concentrations, we found 2 distinct patient populations, which could be distinguished by N:B ratios ranging from 0.01 to 0.2. In addition, while the distribution of urine naloxone concentrations itself did not demonstrate distinct populations, naloxone was able to further flag potential tampered specimens when combined with N:B ratios. Abnormal specimen validity testing was additionally found more commonly in cases with N:B ratios <0.02.

CONCLUSIONS

This comprehensive study compared N:B ratios with naloxone concentrations and specimen validity testing. This study suggests that a N:B ratio of <0.02 in concert with high naloxone concentrations (>1000 ng/ml) can help to identify potential cases of tampered urine samples.

Identification and Management of Opioid Use Disorder in Primary Care: an Update

PURPOSE OF REVIEW

The rising prevalence of opioid use disorder (OUD) and related complications in North America coupled with limited numbers of specialists in addiction medicine has led to large gaps in treatment. Primary care providers (PCPs) are ideally suited to diagnose and care for people with OUD and are increasingly being called upon to improve access to care. This review will highlight the recent literature pertaining to the care of patients with OUD by PCPs.

RECENT FINDINGS

The prevalence of patients with OUD in primary care practice is increasing, and models of office-based opioid treatment (OBOT) are evolving to meet local needs of both ambulatory practices and patients. OBOT has been shown to increase access to care and demonstrates comparable outcomes when compared to more specialty-driven care. OBOT is an effective means of increasing access to care for patients with OUD. The ideal structure of OBOT depends on local factors. Future research must explore ways to increase the identification and diagnosis of patients with OUD, improve treatment retention rates, reduce stigma, and promote interdisciplinary approaches to care.