Journal of Psychosocial Nursing and Mental Health Services

CNE Article 

Little Helpers No More: A Framework for Collaborative Deprescribing of Benzodiazepines in Older Adults

Travis Suss, PharmD, BCGP; Michael Oldani, PhD, MS

Abstract

Benzodiazepines are a class of medications that tend to fly “under the radar” within the general population but nonetheless post a significant risk to older adults when not used appropriately. The current article aims to shine a spotlight on this medication class along with a framework for a team-based approach to successfully de-escalate use when clinically appropriate. [Journal of Psychosocial Nursing and Mental Health Services, 58(1), 23–28.]

Abstract

Benzodiazepines are a class of medications that tend to fly “under the radar” within the general population but nonetheless post a significant risk to older adults when not used appropriately. The current article aims to shine a spotlight on this medication class along with a framework for a team-based approach to successfully de-escalate use when clinically appropriate. [Journal of Psychosocial Nursing and Mental Health Services, 58(1), 23–28.]

What a drag it is getting old…
"Mother's Little Helper," Rolling Stones (1966)

Xans don't make you
Xans gon' take you
Xans gon' fake you
Xans gon' betray you
"Betrayed," Lil Xan (2017)

Leave it to rock-n-rollers and rappers to understand the complex and ever-evolving history of benzodiazepine (BZD) prescribing in the United States. “Benzos” infiltrated popular culture in the 1960s as “mother's little helpers,” an idea popularized by the Rolling Stones (1969), who ironically, became astute observers of cultural life in America. They chronicled how middle-class American women were using “a little yellow pill”—Valium® (diazepam)—to medicate their mundane lives as well as to modulate relationships with husbands and children (Oldani, 2012).

Originally, these anxiolytics enjoyed widespread use in men and women. “Executive Excedrin” was slang for all manner of tranquilizers, including meprobamate, which was heavily prescribed for “tension” in white collar men (Tone, 2009, p. 107). However, according to Tone (2009), BZD prescribing expanded greatly after the 1960s among female patients.

The rapper, Diego Leanos, aka Lil Xan, embodies the newest unfortunate “helper” role for BZDs in the 2010s. During the opioid epidemic, alprazolam (Xanax®) became part of a drug cocktail that includes narcotics, both illegal (heroin) and prescription (Oxycontin®). BZDs are often taken by narcotic users as a way to amplify the effect of intoxication (Jones, Mogali, & Corner, 2012). During an interview with Zisook (2017), Leanos said the following about his addiction: “I was painfully addicted to Xan [Xanax] for like two years of my life…I definitely learned a lesson after ending up in the hospital after withdrawing. I was withdrawing from opioids and benzos” (para. 3).

Leanos is one of the few performers who talks frankly about tapering off these drug combinations and the consequences of remaining on a dangerous polypharmaceutical cocktail. Today, it seems younger patients have become more aware of psychotropic polypharmacy and more empowered to reduce the amount of medications they are prescribed (Aviv, 2019). This may not be the case, however, in the older adult population. The current article presents a framework for collaborative deprescribing among care teams to reduce BZD use in this patient population.

Getting Old on Drugs

Unfortunately, the epidemic of narcotic use over the past 2 decades has called attention to a longer, more invisible epidemic of BZD mis/use in the United States. In particular, the current authors are concerned with BZD use in an increasingly at-risk group of patients—older adults—in whom issues, such as amplification, are more complex.

Maust, Lin, and Blow (2019) recently published a cross-sectional analysis of National Survey on Drug Use and Health Data (10,290 BZD users) in the United States and found that the rate of BZD use in adults age >65 is currently 8.6%. Their results underscored the fact that the misuse (i.e., using without a prescription or not according to prescriptive instructions) accounted for 20% of all use. They highlighted the extreme risks of mis/use with opioids, but also stressed that BZDs pose risks of their own. For instance, they cite Coben et al. (2010), who note that between 1999 and 2006 the largest absolute growth in emergency department visits for poisoning was related to BZDs. Surveys of geriatric experts (e.g., pharmacists, physicians, nurse practitioners) demonstrate that BZDs are consistently ranked the number one priority for deprescribing in older adults (Farrell et al., 2015).

Maust et al. (2019, p. 103) implore clinicians to be “mindful of their role as a potential source of misused medications” and to play a role “in understanding the reason for their patients' misuse to determine the appropriate intervention.” In the current authors' experience, this is a difficult role for clinicians to play without leveraging other specialties (e.g., nursing, pharmacy, social work).

The current authors, through their collaborative work visiting older adults in their homes as well as the pharmacist's role in a geriatric clinic, have found that the misuse of BZDs with and without opioids is common. A team-based framework for deprescribing BZDs to older patients is outlined. Case examples are provided to highlight the complexity of BZD use in older adults and outline a collaborative approach for deprescribing that care teams can initiate with patients and their families. Moreover, through geriatric clinical work and in-home visits it has been learned that the appropriate use (e.g., dosing, clinical indication) of BZDs can be hard to understand for patients, their families, and providers and that deprescribing also demands an equally understandable approach with all stakeholders involved.

Case Examples

Case 1

The current authors (a pharmacist [T.S.] and clinical ethnographer [M.O.]) and a nurse visited Harry, a 73-year-old White man, in his apartment in eastern Wisconsin. He was traveling almost every day by bus to visit his wife, who resides in a nursing home due to chronic pain, obesity, memory issues, and lack of mobility. Harry completed a medication history with the pharmacist, easily discussing his prescriptions for alprazolam and citalopram (selective serotonin reuptake inhibitor antidepressant) for his mood. He understood his medication dosages only in terms of “color and morning or nighttime.” He openly discussed a “break down” he had requiring hospitalization years ago.

When the nurse administered a geriatric depression assessment, Harry began to cry. The extreme sadness of his situation and loneliness had come to the surface. On a return visit, he cried again talking with the nurse and mentioned wanting to “sometimes take his gun…and….” He quickly reassured the care team he was only joking about either using it on himself or his wife. Fortunately, Harry was connected to a social service network to ensure his safety and arrange a mental health referral.

The pharmacist on the team made recommendations to Harry about using his psychiatric medication more appropriately. He was taking the alprazolam (i.e., BZD) as scheduled, 0.5 mg twice per day, and the pharmacist suggested talking to his provider about switching to an as-needed prescription (i.e., a modified deprescribing scenario). From a geriatric point of view, the BZD can cloud thinking and judgment, increase fall risk, and has overdose potential. In addition, the pharmacist recommended staying on citalopram, at the appropriate dose of 20 mg per day, to avoid potentially dangerous cardiovascular side effects. Harry promised to pass the care team's recommendations on to his physician. However, they were not confident that their recommendations would be followed by his provider, or that Harry would see a counselor to address his mood, because he was not being managed by an interprofessional clinic team.

Harry had agreed to participate in a home-visit program designed to help older adults live independently and safely in their homes. (The care team continued long-term follow up with Harry and he remained stable after 1 year.)

Case 2

Following the call for collaborations that improve health outcomes (Cox, Cuff, Brandt, Reevers, & Zierler, 2016), the Concordia University Wisconsin School of Nursing/Office of Interprofessional Practice and Education formed a community-based partnership with a meal delivery service to improve older adult quality of life. Volunteers delivering meals had noticed excessive amounts of medication, signs of mental distress, and cluttered homes. A collaborative team, comprising a nurse, pharmacist, occupational therapist, physical therapist, medical anthropologist, and case manager from the meal program, made a series of home visits starting in summer 2018. Immediately, the team began to encounter other older adults with similar issues to Harry, such as taking BZDs with or without opioids.

The team met 65-year-old Mary Jo, who became an exemplar for problematic drug use in older adults (Oldani et al., 2019). Mary Jo's prescriptions included those affecting the central nervous system, such as nortripty-line, baclofen, fluoxetine, pregabalin, oxycodone/acetaminophen, fentanyl, and clonazepam. She was working toward lowering the doses of her opioids and was able to provide a fairly detailed history: “I used to take 10 doses a day!”

Mary Jo had awareness of the risks of opioids and described how she was actively working with her physician to taper the dose of oxycodone/acetaminophen. She then told the pharmacist that she was taking double the prescribed dose of clonazepam for chronic insomnia. It became clear that the risk of chronic BZD use was never explained to Mary Jo, allowing her to self-titrate. She seemed genuinely surprised when the pharmacist questioned her BZD use. She said that her clonazepam use had not been addressed in years, adding “I [also] like to have a cocktail on weekends; could all this impact my driving?”

The team was concerned about her use of alcohol, BZDs, and opioids for fall risk, impaired driving, and overdose potential. A 3-week follow-up visit was scheduled to provide recommendations. Mary Jo was open to tapering her opioid and clonazepam use. By 3-month follow up, she had talked to her provider, which ultimately led to small dose reductions in fentanyl and clonazepam.

This case represents a soft intervention related to BZD deprescribing, where education and written recommendations for Mary Jo's provider led to tapering a dangerous drug combination. Mary Jo had myriad health problems, especially pain-related issues, requiring serious time and effort from her clinical team. It is not surprising that her clonazepam use had been overlooked or minimized. This scenario is often seen by the current author (T.S.) in his collaborative, ambulatory geriatric practice.

Collaborative Deprescribing: An Interventional Framework

Motivated by these clinical problems, a snapshot report was generated of a local general internal medicine (GIM) clinic on all active prescriptions of potentially inappropriate medications (PIMs), as defined by the Beers Criteria®, currently prescribed for patients age ≥65 (American Geriatrics Society [AGS] Beers Criteria® Update Expert Panel, 2019). This guideline is used by health professionals to aid in the selection and reduction of medications in older adults. Of the identified prescriptions for PIMs, 362 of the total 5,167 were BZDs (Figure 1).

Snapshot report of potentially inappropriate medications within a local general internal medicine clinic as defined by the Beers Criteria® (American Geriatrics Society Beers Criteria® Update Expert Panel, 2019).Note. N = 5,167; CNS = central nervous system; GI = gastrointestinal; NSAIDs = nonsteroidal anti-inflammatory drugs; PPI = proton pump inhibitor.

Figure 1.

Snapshot report of potentially inappropriate medications within a local general internal medicine clinic as defined by the Beers Criteria® (American Geriatrics Society Beers Criteria® Update Expert Panel, 2019).

Note. N = 5,167; CNS = central nervous system; GI = gastrointestinal; NSAIDs = nonsteroidal anti-inflammatory drugs; PPI = proton pump inhibitor.

A chart review of these cases revealed stories similar to that of Mary Jo. BZD use always seemed to be “on the list” of clinical concerns, but often overshadowed by other issues (and drugs) that were prioritized in complicated geriatric patients with chronic issues.

PIMs prompted a collaborative deprescribing initiative (CDI) at the GIM clinic. BZDs became a primary focus and challenge for two reasons. First, providers believed traditional models of care did not provide the time or incentives to address the appropriate use of anxiolytics. Second, BZD use was rarely addressed if the GIM clinic visit was due to a non-mental health issue. Providers believed there was not enough time to “go it alone” when deprescribing.

An agreement emerged in which PIMs would be proactively reviewed by co-located interprofessional teams (i.e., intentional shared clinical workspace) of pharmacists and medical/pharmacy students (Suss & Oldani, 2017). During the pre-visit evaluation of patients, teams flag cases, make specific recommendations for possible deprescribing opportunities, and provide supporting rationale(s). Providers are spared the time-intensive task of studying the electronic medical record to determine appropriateness of PIMs that may be un/related to the patient's chief complaint.

Combating Inertia Through Intentional Collaboration

One problem the GIM clinic team discovered, as reported by Anderson, Stowasser, Freeman, and Scott (2014), was that deprescribing is difficult. Multiple barriers exist that promote prescriber and patient/family resistance. There is cultural inertia in health care to maintain status quo for providers, patients, and their caregivers. In particular, for psychiatric medications, patients may have been taking a drug set for years without any perceived side effects. In addition, clinical barriers exist, such as fear of withdrawal symptoms, aversion to changing prescription(s) or dose initiated by another provider, and an overall lack of understanding of BZD risks in older patients.

The successful implementation of a deprescribing plan requires team-based information gathering during the pre-visit work and review. Key questions include:

  • When was the medication prescribed?
  • How many times has the dose been changed?
  • Has deprescribing/tapering occurred previously? Results of previous attempts?
  • What are the patient's/family's view regarding deprescribing?

The GIM clinic team concluded intentional medication changes are effective when enacted collaboratively and that deprescribing requires a patient-centered approach. The following GIM clinic collaborative framework is based on the protocol of Scott et al. (2015).

  • Embark on the medical record “scavenger hunt.” The medical record must be searched prior to clinic visits for answers to the key questions noted above, then packaged into a concise narrative for prescriber review. Depre-scribing can proceed from this starting point.
  • Advocate for deprescribing when clinically appropriate, despite any past failed attempts.
  • Initiate the specific deprescribing plan: What is the exact strategy for dose reduction? How long should the taper be? When/how will follow up occur? When/how will this be documented? Who will answer specific drug-related questions?
  • Follow up on the new “deprescription.” Similar to a clinical team who provides close follow up whenever a new prescription is written, especially for BZDs, the same effort must be put forth when attempting to deprescribe.

Providers interested in initiating a deprescribing plan may be able to out-source the details to a pharmacist on the team who has extensive training in the pharmacokinetics and pharmacodynamics of medications. Based on medication and patient characteristics, pharmacists can recommend a specific tapering plan that will provide probability of success. Online resources exist to aid in prioritizing deprescribing in patients with complex medication regimens (access https://deprescribing.org; http://medstopper.com; https://tapermd.com).

Past failures should not preclude future deprescribing when patient safety is paramount and when patients would benefit from BZD de-escalation. Taper plans should be flexible and adjustable, with routine follow up (i.e., in person, by phone, e-mail, letters) and patient/family education. All team members must advocate for safe deprescribing through encouragement, persistence, shared decision making, and patient-centered medical management.

For BZDs, which carry the risk of withdrawal effects when de-escalated quickly, team follow up is essential for two reasons. First, to determine if modifications in the deprescribing plan are needed (often this includes lengthening the taper to mitigate potential withdrawal effects). Second, to provide encouragement and reassurance to patients that they are significantly reducing risks for falls and cognitive impairment by de-escalating BZD use.

Results

After implementing the CDI framework pilot over a 2-month period within the pharmacist's practice setting, 50 PIMs were reviewed from 35 older adults within the GIM clinic. Of the 50 PIMs reviewed, 30 were BZDs and targeted for deprescribing. Using the CDI framework, successful deprescribing (defined as intentional dose reduction or discontinuation without adverse effects) was achieved in 72% of the BZD prescriptions targeted within 3 months of the initial recommendation to deprescribe. Through informal discussions with providers, a common theme emerged describing the CDI as “the final push” they needed to commit to a BZD deprescribing plan. Clearly, the “why” and “when” to deprescribe BZD is well established and known by providers. Nevertheless, the CDI framework offered a guide on how to leverage members of the health care team to achieve more successful outcomes (Thompson & Farrell, 2013). This framework could be tailored to meet the needs of different clinical sites and the populations they serve.

Discussion

Deprescribing of BZDs can be a slow process because of the biopsychosocial nature of dependence (Guina & Merrill, 2018). Treatment of any chronic disease through medication management demands close follow up and team-based care to improve patient compliance and outcomes. Successful deprescribing of BZDs requires a similar mindset. According to Oldani (2014), clinicians have learned that long-term mis/use of BZDs (or any psychotropic medication) requires a person-centered approach that recognizes processes of pharmaceutical detox (i.e., deprescribing) and undiagnosing (i.e., the loss of illness-identity) can be disruptive for patients and caregivers. Providers must use and leverage the expertise of other health professionals on the team (e.g., nurses, pharmacists, social workers) for routine follow up, accessibility, and encouragement to patients and families as they begin to live a life no longer dependent on BZDs.

Collaborative deprescribing will look different depending on the setting and resources available. In a perfect clinical world, collaborative teams could make home visits to target at-risk older adults taking multiple medications, access their health records, and work directly with their providers to elicit change. Conversely, a practice site, such as a comprehensive team-based geriatric clinic, can do the work of deprescribing (with providers present) using shared medical records. However, care teams must acknowledge that medication changes will be enacted outside the clinic (i.e., in homes or long-term care facilities) and may be enacted imperfectly.

Conclusion

A cultural mindset is needed that makes deprescribing a priority and acknowledges that the burden should be shared by the clinical team, the patient, and the family/caregiver. The ethnographer coauthor (M.O.) has worked with numerous psychiatrists and pharmacists who now prioritize deprescribing in their daily practices (DeJongh & Oldani, 2018; Oldani, 2014). These practitioners work to create meaningful collaborations with all stakeholders. They are careful to recognize that attachment to drugs, especially BZDs, is multi-dimensional and requires time, patient education, and interprofessional communication.

Between 2004 and 2015, the percentage of generic BZD prescriptions written in the United States doubled in the liminal clinical space of mis/use, especially in primary care outpatient settings (Agarwal & Landon, 2019). In terms of actual numbers, this translated to 94 million legal prescriptions in 2012 (Miller, 2012). BZDs are used medically for a range of maladies from panic disorder to palliation at the end of life. However, their efficacy, side effects, debilitating withdrawal symptoms, and life-threatening interactions with opioids and alcohol require a constant vigilance and awareness. The cases and framework presented herein are an attempt to contribute to the growing practice and discourse of collaborative deprescribing (Fineberg, Gupta, & Leavitt, 2019) in highly vulnerable groups of patients.

References

  • Agarwal, S. D. & Landon, B. E. (2019). Patterns of outpatient benzodiazepine prescribing in the United States. JAMA Network Open, 2(1), e187399. https://doi.org/10.1001/jamanetworkopen.2018.7399 PMID: doi:10.1001/jamanetworkopen.2018.7399 [CrossRef]
  • American Geriatrics Society Beers Criteria® Update Expert Panel. (2019). Updated AGS Beers Criteria® for potentially inappropriate medication use in older adults. Journal of the American Geriatrics Society, 67(4), 674–694. https://doi.org/10.1111/jgs.15767 PMID: doi:10.1111/jgs.15767 [CrossRef]
  • Anderson, K., Stowasser, D., Freeman, C. & Scott, I. (2014). Prescriber barriers and enablers to minimising potentially inappropriate medications in adults: A systematic review and thematic synthesis. BMJ Open, 4(12), e006544. https://doi.org/10.1136/bmjopen-2014-006544 PMID: doi:10.1136/bmjopen-2014-006544 [CrossRef]25488097
  • Aviv, R. (2019, April8). The challenge of going off psychiatric drugs. Retrieved from https://www.newyorker.com/magazine/2019/04/08/the-challenge-of-going-off-psychiatric-drugs
  • Coben, J. H., Davis, S. M., Furbee, P. M., Sikora, R. D., Tillotson, R. D. & Bossarte, R. M. (2010). Hospitalizations for poisoning by prescription opioids, sedatives, and tranquilizers. American Journal of Preventive Medicine, 38(5), 517–524. https://doi.org/10.1016/j.amepre.2010.01.022 PMID: doi:10.1016/j.amepre.2010.01.022 [CrossRef]20409500
  • Cox, M., Cuff, P., Brandt, B., Reeves, S. & Zierler, B. (2016). Measuring the impact of interprofessional education on collaborative practice and patient outcomes. Journal of Interprofessional Care, 30(1), 1–3. https://doi.org/10.3109/13561820.2015.1111052 PMID: doi:10.3109/13561820.2015.1111052 [CrossRef]26833103
  • DeJongh, B. & Oldani, M. (2018). Case reports of interprofessional care for clients enrolled in a mental health court. Mental Health Clinician, 8(6), 317–321. https://doi.org/10.9740/mhc.2018.11.317 PMID: doi:10.9740/mhc.2018.11.317 [CrossRef]30397575
  • Farrell, B., Tsang, C., Raman-Wilms, L., Irving, H., Conklin, J. & Pottie, K. (2015). What are priorities for deprescribing for elderly patients? Capturing the voice of practitioners: A modified delphi process. PLoS One, 10(4), e0122246. https://doi.org/10.1371/journal.pone.0122246 PMID: doi:10.1371/journal.pone.0122246 [CrossRef]25849568
  • Fineberg, S. K., Gupta, S. & Leavitt, J. (2019). Collaborative deprescribing in borderline personality disorder: A narrative review. Harvard Review of Psychiatry, 27(2), 75–86. https://doi.org/10.1097/HRP.0000000000000200 PMID: doi:10.1097/HRP.0000000000000200 [CrossRef]30676404
  • Guina, J. & Merrill, B. (2018). Benzodiazepines I: Upping the care on downers: The evidence of risks, benefits and alternatives. Journal of Clinical Medicine, 7(2), 17. https://doi.org/10.3390/jcm7020017 PMID: doi:10.3390/jcm7020017 [CrossRef]
  • Jones, J. D., Mogali, S. & Comer, S. D. (2012). Polydrug abuse: A review of opioid and benzodiazepine combination use. Drug and Alcohol Dependence, 125(1–2), 8–18. doi:10.1016/j.drugalcdep.2012.07.004 [CrossRef]22857878
  • Lil, Xan. (2017). Betrayed. On Xanarchy [album]. New York, NY: Columbia/Sony.
  • Maust, D. T., Lin, L. A. & Blow, F. C. (2019). Benzodiazepine use and misuse among adults in the United States. Psychiatric Services (Washington, D.C.), 70(2), 97–106. doi:10.1176/appi.ps.201800321 [CrossRef]
  • Miller, L. (2012, March6). Listening to Xanax. Retrieved from http://nymag.com/news/features/xanax-2012-3/
  • Oldani, M. (2012). The pharmaceuticalized “good mother.”. Retrieved from https://www.academia.edu/2209305/The_Pharmaceuticalization_of_the_Good_Mother
  • Oldani, M. (2014). Deep pharma: Psychiatry, anthropology, and pharmaceutical detox. Culture, Medicine, and Psychiatry, 38(2), 255–278. doi:10.1007/s11013-014-9369-8 [CrossRef]
  • Oldani, M., Chappy, S., Harrison, L., Kukor, S., Suss, T. & Stoehr, N. (2019). Advancing senior care and aging in place through collaborative, in-home visits: A novel community-university partnership. Collaborative Healthcare: Interprofessional Practice, Education and Evaluation, 10(1), 2.
  • The Rolling Stones. (1966). Mother's little helper. On Aftermath [album]. Hollywood, CA: RCA.
  • Scott, I. A., Hilmer, S. N., Reeve, E., Potter, K., Le Couteur, D., Rigby, D. & Martin, J. H. (2015). Reducing inappropriate polypharmacy: The process of deprescribing. JAMA Internal Medicine, 175(5), 827–834. https://doi.org/10.1001/jamainternmed.2015.0324 PMID: doi:10.1001/jamainternmed.2015.0324 [CrossRef]25798731
  • Suss, T. & Oldani, M. (2017). It matters where you sit: Co-location, interprofessional rapport and a geriatric nexus site. Paper presented at Collaborating Across Borders Conference. , Banff, Alberta, Canada. .
  • Thompson, W. & Farrell, B. (2013). Deprescribing: What is it and what does the evidence tell us?Canadian Journal of Hospital Pharmacy, 66(3), 201–202. https://doi.org/10.4212/cjhp.v66i3.1261 PMID: doi:10.4212/cjhp.v66i3.1261 [CrossRef]23814291
  • Tone, A. (2009).The age of anxiety: A history of America's turbulent affair with tranquilizers. New York, NY: Basic Books.
  • Zisook, B. (2017, October19). A rapper named Lil Xan talks about his painful Xanax addiction & recovery. Retrieved from https://djbooth.net/features/2017-10-19-lil-xan-xanax-addiction
Authors

Dr. Suss is Board Certified Geriatric Pharmacist and Assistant Professor of Pharmacy Practice, and Dr. Oldani is Director of Interprofessional Practice and Education and Associate Professor of Pharmaceutical Sciences and Administration, Concordia University Wisconsin, Mequon, Wisconsin.

The authors have disclosed no potential conflicts of interest, financial or otherwise. The Fresh Meals on Wheels (FMOW)-Concordia University Wisconsin in-home project has been funded through the Council of Independent Colleges and the Retirement Research Foundation grants. Human subjects research was approved, including permissions for using the Mini Cog/Geriatric Depression Scale, through Concordia's Human Subjects Review Board (ref. # 50620T-70714-313).

The authors thank Sharon Chappy, Lois Harrison, and Stacy Kukor from Concordia University Wisconsin for their clinical contributions to cases mentioned above; community research partner, FMOW of Sheboygan County, Wisconsin; and Kelly Heyn and Maureen Fatla.

Address correspondence to Michael Oldani, PhD, MS, Office of Interprofessional Practice and Education, Concordia University Wisconsin, SOP #299, 12800 North Lake Shore Drive, Mequon, WI 53097; e-mail: ipe@cuw.edu.

Received: June 13, 2019
Accepted: September 23, 2019

10.3928/02793695-20191218-05

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