Urine and oral fluid drug testing in support of pain management.

In recent years, the abuse of opioid drugs has resulted in greater prevalence of addiction, overdose, and deaths attributable to opioid abuse. The epidemic of opioid abuse has prompted professional and government agencies to issue practice guidelines for prescribing opioids to manage chronic pain. An important tool available to providers is the drug test for use in the initial assessment of patients for possible opioid therapy, subsequent monitoring of compliance, and documentation of suspected aberrant drug behaviors. This review discusses the issues that most affect the clinical utility of drug testing in chronic pain management with opioid therapy. It focuses on the two most commonly used specimen matrices in drug testing: urine and oral fluid. The advantages and disadvantages of urine and oral fluid in the entire testing process, from specimen collection and analytical methodologies to result interpretation are reviewed. The analytical sensitivity and specificity limitations of immunoassays used for testing are examined in detail to draw attention to how these shortcomings can affect result interpretation and influence clinical decision-making in pain management. The need for specific identification and quantitative measurement of the drugs and metabolites present to investigate suspected aberrant drug behavior or unexpected positive results is analyzed. Also presented are recent developments in optimization of test menus and testing strategies, such as the modification of the standard screen and reflexed-confirmation testing model by eliminating some of the initial immunoassay-based tests and proceeding directly to definitive testing by mass spectrometry assays.

Ethanol Biomarker Testing and Challenges.

CONTEXT.­: Clinical and forensic testing for ethanol biomarkers, including ethyl glucuronide (EtG) and ethyl sulfate (EtS), is used to discern alcohol use from abstinence. These markers can be key in major decisions, including transplant eligibility or retaining licensure after alcohol misuse. Accuracy, precision, and recognition of the implications of reporting cutoffs are all essential for correct interpretation. OBJECTIVE.­: To evaluate trends in testing for EtG and EtS, including how laboratories perform testing and how comparable participant results are. DESIGN.­: The study examined the College of American Pathologists ethanol biomarker proficiency testing survey from 2013 to 2019. Trends in methodology, reporting cutoffs, and participant performance were evaluated for qualitative and quantitative EtG testing and for quantitative EtS testing. RESULTS.­: There was little consensus in reporting cutoffs, which ranged from 10 to 1000 ng/mL for EtG and 10 to 1500 ng/mL for EtS. Although median EtG and EtS compared well with target concentrations, individual participants' results varied widely. For quantitative enzyme immunoassay, accuracy and precision were best in EtG challenges less than 1500 ng/mL. For EtG or EtS by mass spectrometry, overall accuracy was good over a wide concentration range, but variability between participants was high. Approximately 10% (409 of 4059) of results were unacceptable, which for mass spectrometry corresponded to more than 35% above or below the group mean. CONCLUSIONS.­: Although many participants performed well, there was insufficient consensus in reporting cutoffs, and a consistent fraction of laboratories failed to achieve survey standards. Guidelines for assay performance and reporting could greatly benefit laboratories and end users.

Therapeutic Drug Monitoring of Second- and Third-Generation Antiepileptic Drugs.

CONTEXT.­: Therapeutic drug monitoring has traditionally been widely used for first-generation antiepileptic drugs (AEDs) such as carbamazepine and phenytoin. The last 2 decades have seen the introduction of second- and third-generation AEDs (eg, lamotrigine, levetiracetam, and topiramate) into clinical practice. OBJECTIVE.­: To use data from the College of American Pathologists Therapeutic Drug Monitoring, Extended Proficiency Testing Survey to determine the performance of assays used for therapeutic drug monitoring of newer AEDs, including comparison of enzyme immunoassay and chromatographic techniques. DESIGN.­: Six years of proficiency testing surveys were reviewed (2013-2018). RESULTS.­: Steady growth was seen in participant volumes for newer AEDs. The analytical performance of automated enzyme immunoassays for lamotrigine, levetiracetam, and topiramate was similar to that of chromatographic methods, consistent with published literature using patient samples for comparisons. The majority of participating laboratories now use enzyme immunoassays to measure levetiracetam. CONCLUSIONS.­: Survey results reflect steadily growing interest in therapeutic drug monitoring of newer AEDs. The increasing availability of robust immunoassays for new AEDs should facilitate their clinical utility, especially for clinical laboratories that do not perform chromatographic assays for therapeutic drug monitoring.

Interpretation and Utility of Drug of Abuse Screening Immunoassays: Insights From Laboratory Drug Testing Proficiency Surveys.

CONTEXT.­: Urine drug testing is frequently ordered by health care providers. Immunoassays are widely used for drug testing, yet have potential limitations, including variable cross-reactivity. The last decade has seen worsening of a prescription drug abuse epidemic. OBJECTIVE.­: To use data from a College of American Pathologists proficiency testing survey, Urine Drug Testing, Screening, to determine and summarize the characteristics, performance, and limitations of immunoassays. DESIGN.­: Seven years of proficiency surveys were reviewed (2011-2017). RESULTS.­: Rapid growth was seen in participant volumes for specific immunoassays for synthetic opioids (eg, buprenorphine, fentanyl, oxycodone) and 3,4-methylenedioxymethamphetamine ("ecstasy"). Participant volumes remained high for immunoassays targeting less commonly abused drugs such as barbiturates and phencyclidine. For opiate immunoassays, the number of laboratories using a 2000 ng/mL positive cutoff remained stable, and an increasing number adopted a 100 ng/mL cutoff. Opiate and amphetamine immunoassays showed high variability in cross-reactivity for drugs other than the assay calibrator. Assays targeting a single drug or metabolite generally performed well on drug challenges. CONCLUSIONS.­: Survey results indicate strong clinical interest in urine drug testing and some adoption of new assays. However, urine drug testing availability does not parallel prevailing patterns of drug prescribing and abuse patterns. In particular, specific immunoassays for synthetic opioids and a lower positive cutoff for opiate immunoassays may be underused, whereas immunoassays for barbiturates, methadone, propoxyphene, and phencyclidine may be overused. Laboratories are encouraged to review their test menu, cutoffs, and assay performance and adjust their test offerings based on clinical needs and technical capabilities.

The effect of famotidine, esomeprazole, and ezetimibe on levothyroxine absorption.

BACKGROUND: Recent literature describing the effect of gastric acid suppression on levothyroxine absorption has been inconsistent. Also, ezetimibe, a lipid-lowering compound that inhibits intestinal absorption of cholesterol, may interfere with levothyroxine absorption. The objective of this study was to measure changes in levothyroxine absorption before and after famotidine, esomeprazole or single-dose ezetimibe." METHODS: We conducted levothyroxine absorption testing on 30 healthy volunteers, excluding those with thyroid disease. Subjects were randomized to receive one of three regimens: 1 week of either famotidine or esomeprazole, or a single dose of ezetimibe administered simultaneously with levothyroxine (n = 10 in each group). Baseline levothyroxine absorption testing was performed on all subjects using 600 mcg of Synthroid with thyroid hormone levels checked at 0, 2, 4, 6, and 8 hours after administration, and then repeated 6 weeks later, after administration of one of the three study drug regimens. The area under the curve (AUC) over 8 hours for serum thyroxine (T4), triiodothyronine (T3), and free T4 index, and the mean peak hormone levels achieved during levothyroxine absorption testing at baseline and following administration of one of the three study medications were compared using paired t-tests. RESULTS: Peak mean hormone levels and AUCs of T4, T3, and free T4 index during absorption testing before and after each of three study medications did not differ. Results for differences before and after study medication did not reach significance even when using the subtractive correction method of AUC calculation. CONCLUSIONS: No differences were noted in levothyroxine absorption after gastric acid suppression with 1 week of famotidine or esomeprazole. A simultaneously administered dose of ezetimibe did not significantly change levothyroxine absorption.

123I thyroid uptake and thyroid size at 24, 48, and 72 hours after the administration of recombinant human thyroid-stimulating hormone to normal volunteers.

CONTEXT: Recombinant human TSH (rhTSH) is used to evaluate thyroid carcinoma patients and off-label for (131)I thyroid ablation and nontoxic goiter therapy. OBJECTIVE: Our objective was to determine the optimal time for (131)I administration after rhTSH. PARTICIPANTS: Twenty-five euthyroid nongoitrous volunteers participated in the study. DESIGN: Baseline 24-h thyroid (123)I uptake (RAIU) was measured, and then 0.1 mg rhTSH was administered. (123)I was administered 24, 48, or 72 h after rhTSH, and a repeat 24-h RAIU was obtained. SETTING: The study was conducted at an academic research center. MAIN OUTCOME MEASURES: Thyroid function tests, thyroid ultrasounds, and electrocardiograms were measured before rhTSH, then daily for 4 d, and finally 7 d after rhTSH. RESULTS: Serum TSH concentrations 24 h after rhTSH increased from 1.7 +/- 0.5 muU/ml (mean +/- sd) to 13.3 +/- 4. The 24-h RAIUs rose from 25 +/- 5 to 47 +/- 8% (88% increase) when the (123)I was given at 24 h after rhTSH and from 29.8 +/- 7 to 40.5 +/- 13% (36% increase) when the (123)I was given at 48 h and were unchanged when the (123)I was given at 72 h. The post-rhTSH RAIU increase was greater at 24 than at 72 h (P < 0.005) and marginally greater than at 48 h (P = 0.057). Thyroid volumes significantly increased 48 h after rhTSH (10 +/- 3.8 vs. 11.1 +/- 3.7 ml; P < 0.009). Electrocardiograms were normal. CONCLUSIONS: Marked increases in RAIU occurred when (123)I was given 24 h after rhTSH administration to euthyroid volunteers. Smaller increases were observed at 48 h and none at 72 h.

Effects of six months of daily low-dose perchlorate exposure on thyroid function in healthy volunteers.

CONTEXT: Perchlorate has been detected in U.S. drinking water supplies at levels ranging from 4 to 200 microg/liter as well as in agricultural products. Perchlorate is known to be a competitive inhibitor of iodine uptake by the thyroid through the sodium-iodide symporter. OBJECTIVE: The objective of the study was to determine whether prolonged exposure (6 months) to low levels of perchlorate would perturb thyroid function. DESIGN: This was a prospective, double-blinded, randomized trial. PARTICIPANTS: The study population consisted of 13 healthy volunteers. INTERVENTION: INTERVENTIONs included placebo vs. 0.5 mg or 3.0 mg potassium perchlorate daily. MAIN OUTCOME MEASURES: Serum thyroid function tests, 24-h radioactive iodine uptake, serum thyroglobulin (Tg), urinary iodine and perchlorate, and serum perchlorate were measured. RESULTS: Mean urinary perchlorate value during ingestion of 0.5 mg perchlorate daily was 332.7 +/- 66.1 microg per 24 h or 248.5 +/- 64.5 microg/g creatinine and mean values for the four subjects who received 3 mg perchlorate daily were 2079.5 +/- 430.0 microg per 24 h or 1941.7 +/- 138.5 microg/g creatinine. There was no significant change in the thyroid (123)I uptakes during perchlorate administration. There were no significant changes in serum T(3), free T(4) index, TSH, or Tg concentrations during the exposure period, compared to baseline or postexposure values. Urine iodine values for the 3-mg perchlorate group were higher, but not significantly so, at baseline than during perchlorate exposure. CONCLUSIONS: We observed that a 6-month exposure to perchlorate at doses up to 3 mg/d had no effect on thyroid function, including inhibition of thyroid iodide uptake as well as serum levels of thyroid hormones, TSH, and Tg.

See, Test & Treat: A 5-Year Experience of Pathologists Driving Cervical and Breast Cancer Screening to Underserved and Underinsured Populations.

CONTEXT: - See, Test & Treat is a pathologist-driven program to provide cervical and breast cancer screening to underserved and underinsured patient populations. This program is largely funded by the CAP Foundation (College of American Pathologists, Northfield, Illinois) and is a collaborative effort among several medical specialties united to address gaps in the current health care system. OBJECTIVE: - To provide an outline for administering a See, Test & Treat program, using an academic medical center as a model for providing care and collating the results of 5 years of data on the See, Test & Treat program's findings. DESIGN: - Sources include data from patients seen at Tufts Medical Center (Boston, Massachusetts) who presented to the See, Test & Treat program and institutional data between 2010 and 2014 detailing the outline of how to organize and operationalize a volunteer cancer-screening program. RESULTS: - During the 5-year course of the program, 203 women were provided free cervical and breast cancer screening. Of the 169 patients who obtained Papanicolaou screening, 36 (21.3%) had abnormal Papanicolaou tests. In addition, 16 of 130 patients (12.3%) who underwent mammography had abnormal findings. CONCLUSIONS: - In general, women from ethnic populations have barriers that prevent them from participating in cancer screening. However, the CAP Foundation's See, Test & Treat program is designed to reduce those barriers for these women by providing care that addresses cultural, financial, and practical issues. Although screening programs are helpful in identifying those who need further treatment, obtaining further treatment for these patients continues to be a challenge.

The effect of perchlorate, thiocyanate, and nitrate on thyroid function in workers exposed to perchlorate long-term.

Perchlorate (ClO(4)(-)) and thiocyanate (SCN(-)) are potent and nitrate (NO(3)(-)) a weak competitive inhibitor of the thyroid sodium-iodide symporter. To determine the effects of long-term, high ClO(4)(-) exposure on thyroid function, we conducted a study of 29 workers employed for at least 1.7 yr (50% over 5.9 yr) in an ammonium ClO(4)(-) production plant in Utah. Serum ClO(4)(-), SCN(-), and NO(3)(-); serum T(4), free T(4) index, total T(3), thyroglobulin (Tg), and TSH; 14-h thyroid radioactive iodine uptake (RAIU); and urine iodine (I) and ClO(4)(-) were assessed after 3 d off (Pre) and during the last of three 12-h night shifts in the plant (During) and in 12 volunteers (C) not working in the plant. Serum and urine ClO(4)(-) were not detected in C; urine ClO(4)(-) was not detected in 12 of 29 and was 272 microg/liter in 17 Pre workers; serum ClO(4)(-) was not detected in 27 of 29 Pre; and serum and urine ClO(4)(-) were markedly elevated during ClO(4)(-) exposure to 868 microg/liter and 43 mg/g creatinine, respectively. Serum SCN(-) and NO(3)(-) concentrations were similar in all groups. Thyroid RAIUs were markedly decreased in During compared with Pre (13.5 vs. 21.5%; P < 0.01, paired t) and were associated with an increase in urine I excretion (230 vs. 148 microg I/g Cr; P = 0.02, paired t) but were similar to those in the C group (14.4%). Serum TSH and Tg concentrations were normal and similar in the three groups. Serum T(4) (8.3 vs. 7.7 microg/dl), free T(4) index (2.4 vs. 2.2), and total T(3) (147 vs. 134 ng/dl) were slightly but significantly increased in the During vs. Pre workers (P < 0.01, paired t). Thyroid volumes and patterns by ultrasound were similar in the 29 workers and 12 community volunteers. In conclusion, high ClO(4)(-) absorption during three nights work exposure decreased the 14-h thyroid RAIU by 38% in ClO(4)(-) production workers compared with the RAIU after 3 d off. However, serum TSH and Tg concentrations and thyroid volume by ultrasound were not affected by ClO(4)(-), suggesting that long-term, intermittent, high exposure to ClO(4)(-) does not induce hypothyroidism or goiter in adults.

Is elevated plasma B-natriuretic peptide in amyloidosis simply a function of the presence of heart failure?

This study sought to determine plasma levels of B-natriuretic peptide (BNP) in patients with light-chain-associated amyloidosis and correlate them with the presence or absence of heart failure (HF) and the presence or absence of echocardiographic abnormalities. Patients with normal echocardiographic results had significantly lower BNP levels than those with echocardiographic features of cardiac amyloidosis, whereas BNP levels in the group with HF did not differ from those in patients with asymptomatic cardiac amyloidosis. This observation supports previous observations, suggesting that the elevation of BNP in cardiac amyloidosis may be due not only to elevated ventricular filling pressure but also to direct myocyte damage due to extracellular deposits of amyloid.

Quantitative serum free light chain assay in the diagnostic evaluation of AL amyloidosis.

We compared a new serum immunoassay for quantitation of serum free light chains (FLC) with the conventional tests for clonal immunoglobulin production: bone marrow immunohistochemistry, serum immunofixation electrophoresis, and urine immunofixation electrophoresis. Serum samples from 169 patients with AL amyloidosis and 20 controls were examined. Elevated levels of kappa-FLC and lambda-FLC were found in 94% and 93% of patients with the respective clonal disease. However, false positive elevations of kappa-FLC and lambda-FLC were found in 30% and 44% of patients with clonal disease of the other light chain subtype. We found that the FLC level was a reliable test for the diagnosis of clonal disease when the FLC kappa:lambda ratio was abnormal and was comparable to the conventional tests in patients with AL amyloidosis. After a histologic tissue diagnosis of amyloidosis, determining the type as AL amyloidosis relies on a panel of hematologic tests to determine light chain clonality and the exclusion other forms of amyloidosis.

The Pathologist Workforce in the United States: II. An Interactive Modeling Tool for Analyzing Future Qualitative and Quantitative Staffing Demands for Services.

CONTEXT: Pathologists are physicians who make diagnoses based on interpretation of tissue and cellular specimens (surgical/cytopathology, molecular/genomic pathology, autopsy), provide medical leadership and consultation for laboratory medicine, and are integral members of their institutions' interdisciplinary patient care teams. OBJECTIVE: To develop a dynamic modeling tool to examine how individual factors and practice variables can forecast demand for pathologist services. DESIGN: Build and test a computer-based software model populated with data from surveys and best estimates about current and new pathologist efforts. RESULTS: Most pathologists' efforts focus on anatomic (52%), laboratory (14%), and other direct services (8%) for individual patients. Population-focused services (12%) (eg, laboratory medical direction) and other professional responsibilities (14%) (eg, teaching, research, and hospital committees) consume the rest of their time. Modeling scenarios were used to assess the need to increase or decrease efforts related globally to the Affordable Care Act, and specifically, to genomic medicine, laboratory consolidation, laboratory medical direction, and new areas where pathologists' expertise can add value. CONCLUSIONS: Our modeling tool allows pathologists, educators, and policy experts to assess how various factors may affect demand for pathologists' services. These factors include an aging population, advances in biomedical technology, and changing roles in capitated, value-based, and team-based medical care systems. In the future, pathologists will likely have to assume new roles, develop new expertise, and become more efficient in practicing medicine to accommodate new value-based delivery models.

Modifiers of patient-controlled analgesia efficacy. II. Chronic pain.

Fifty-eight gynecologic surgical patients using patient-controlled analgesia (PCA) were given several psychological questionnaires and their pain was monitored postoperatively. Pain scores were recorded hourly on postoperative day 1. In addition, patients were asked to score retrospectively their overall pain experience while using PCA (Patient Overall Evaluation). Patients having had a history of pain for at least 6 months were considered to have 'chronic pain,' while those who had no history of chronic pain were grouped as 'acute pain' patients. Chronic pain patients spent more time in 'moderate' pain than did acute pain patients. While patients with a history of chronic pain had higher scores on the hourly pain scale compared to acute pain patients, there were no differences between the two groups on the Patient Overall Evaluation. In addition, chronic pain patients reported the same pain levels after completion of PCA as they did during its use, in contrast to acute pain patients whose retrospective pain levels were higher than during PCA use. Compared to acute pain patients, chronic pain patients had higher scores on both the Hypochondriasis and the Hysteria scales of the MMPI. A history of chronic pain may affect the use of patient-controlled analgesia since chronic pain patients may accommodate to a 'moderate' pain level which approximates their preoperative perception of pain. By contrast, acute pain patients who have no 'chronic pain experience' may self-administer pain medication so as to attain a predominately 'mild' level of pain.

Modifiers of patient-controlled analgesia efficacy. I. Locus of control.

The effectiveness of patient-controlled analgesia (PCA) depends upon the patient's appropriate response to a strong aversive stimulus (i.e., pain) with subsequent reinforcement (i.e., opiate injection). Each patient may have psychological characteristics that modify this response to aversive stimuli. To test for such characteristics, 76 female patients undergoing abdominal gynecologic procedures were given psychological tests (i.e., the Chance External, Powerful Others External, and Internal subscales of the Multidimensional Health Locus of Control; the Activities of Daily Living scale; and the Hypochondriasis, Depression, and Hysteria scales of the Minnesota Multiphasic Personality Inventory). Patients utilized PCA for postoperative analgesia. At the completion of PCA, patients were given a questionnaire assessing both the level of pain and degree of satisfaction with pain relief. Correlational analysis compared the level of pain and degree of satisfaction with results of psychological testing. Results showed that female patients with an external locus of control had higher levels of pain and greater dissatisfaction with PCA. An internal locus of control was predictive of lower pain scores and increased satisfaction. PCA effectiveness, as measured by the level of pain and degree of patient satisfaction, correlated with results of psychological testing. The delineation of these and other possible modifiers of PCA efficacy may define populations that are optimally responsive to PCA.