Multiple drug ingestion by ecstasy abusers in the United States.

The abuse of ecstasy-type drugs such as 3,4-methylenedioxymethamphetamine (MDMA) and 3,4-methylenedioxyamphetamine (MDA) is generally associated with young adults attending "Rave" parties. Little toxicological information has been reported regarding ecstasy usage by individuals undergoing monitoring in other settings in the United States. The goal of this study was to determine the prevalence and patterns of licit and illicit drugs in urine specimens of ecstasy users. A survey of laboratory data over the years 2005-2007 revealed that 198 urine specimens were confirmed positive (cutoff concentration 100 ng/mL) for MDMA and/or MDA from the following types of donors ( positive specimens): Correctional (159); Sports (19); Workplace (9); Pain Patients (8); and Special Test Requests (3). Of these, 122 (61.6%) were positive for MDMA and MDA, 70 (35.4%) were positive for MDMA, and 6 (3.0%) were positive for MDA. A majority (84.3%) of the specimens contained multiple drugs and/or metabolites in addition to MDMA and MDA. The median number of drugs/metabolites reported for these ecstasy users was 5 (range, 1-9). In addition to MDMA/MDA, the most commonly identified drug groups (%) were cannabis (THCCOOH) (61.6%); amphetamine/ methamphetamine (38.4%); benzoylecgonine (30.8%); diazepam-related (9.6%); opiates (7.1%); alprazolam (5.6%); and others (5.6%). Although multidrug ingestion appears to be common amongst ecstasy users, caution is recommended in interpretation. Illicit ecstasy in the United States and Canada frequently contains methamphetamine and other active substances, and multidrug use may not have been intentional.

Normalization of urinary drug concentrations with specific gravity and creatinine.

Excessive fluid intake can substantially dilute urinary drug concentrations and result in false-negative reports for drug users. Methods for correction ("normalization") of drug/metabolite concentrations in urine have been utilized by anti-doping laboratories, pain monitoring programs, and in environmental monitoring programs to compensate for excessive hydration, but such procedures have not been used routinely in workplace, legal, and treatment settings. We evaluated two drug normalization procedures based on specific gravity and creatinine. These corrections were applied to urine specimens collected from three distinct groups (pain patients, heroin users, and marijuana/ cocaine users). Each group was unique in characteristics, study design, and dosing conditions. The results of the two normalization procedures were highly correlated (r=0.94; range, 0.78-0.99). Increases in percent positives by specific gravity and creatinine normalization were small (0.3% and -1.0%, respectively) for heroin users (normally hydrated subjects), modest (4.2-9.8%) for pain patients (unknown hydration state), and substantial (2- to 38-fold increases) for marijuana/cocaine users (excessively hydrated subjects). Despite some limitations, these normalization procedures provide alternative means of dealing with highly dilute, dilute, and concentrated urine specimens. Drug/metabolite concentration normalization by these procedures is recommended for urine testing programs, especially as a means of coping with dilute specimens.

Evidence that morphine is metabolized to hydromorphone but not to oxymorphone.

A minor pathway for the biotransformation of morphine to hydromorphone has been identified in humans. Recently, an unsubstantiated claim that morphine is metabolized to hydromorphone and then to oxymorphone was published. The goal of this study was to determine if credible evidence that oxymorphone is a metabolite of either morphine or hydromorphone exists. Urine specimens from pain patients who were treated exclusively with high daily doses of morphine (N = 34) or hydromorphone (N = 26) were analyzed by liquid chromatography-tandem mass spectrometry for oxymorphone, hydromorphone, and morphine (LOD = 25 ng/mL). Specimens were also tested for a variety of other medications. Criteria for inclusion of patients' specimens were as follows: 1. patients were undergoing exclusive dosing with either morphine or hydromorphone; 2. non-prescribed medications were not detected; and 3. urine concentrations of morphine were > 100,000 ng/mL for the high-dose morphine group and > 1,000 ng/mL of hydromorphone for the high-dose hydromorphone group. Consistent with earlier reports, hydromorphone was detected in patients treated with high-dose morphine. The ratio of hydromorphone to morphine ranged from 0.2 to 2.2%. Oxymorphone was not detected in any specimen from high-dose morphine or high-dose hydromorphone patients. The authors conclude, based on these data, that oxymorphone is not a metabolite of morphine or hydromorphone.

Drug-Drug Interaction Assessment and Identification in the Primary Care Setting.

BACKGROUND: Drug-drug interactions (DDIs) are ubiquitous, harmful and a leading cause of morbidity and mortality. With an aging population, growth in polypharmacy, widespread use of supplements, and the rising opioid abuse epidemic, primary care physicians (PCPs) are increasingly challenged with identifying and preventing DDIs. We set out to evaluate current clinical practices related to identifying and treating DDIs and to determine if opportunities to increase prevention of DDIs and their adverse events could be identified. METHODS: In a nationally representative sample of 330 board-certified family and internal medicine practitioners, we evaluated whether PCPs assessed DDIs in the care they provided for three simulated patients. The patients were taking common prescription medications (e.g. opioids and psychiatric medications) along with other common ingestants (e.g. supplements and food) and presented with symptoms of DDIs. Physicians were scored on their ability to inquire about the patient's medications, investigate possible DDIs, evaluate the patient, and provide treatment recommendations. We scored the physicians' care recommendations against evidence-based criteria, including overall care quality and treatment for DDIs. RESULTS: Average overall quality of care score was 50.5% ± 12.0%. Despite >99% self-reported use of medication reconciliation practices and tools, physicians identified DDIs in only 15.3% of patients, with 15.5% ± 20.3% of DDI-specific treatment by the physicians. CONCLUSIONS: PCPs in this study did not recognize or adequately treat DDIs. Better methods are needed to screen for DDIs in the primary care setting.

Oral fluid drug testing of chronic pain patients. II. Comparison of paired oral fluid and urine specimens.

A clinical study was conducted to compare the use of oral fluid to urine for compliance monitoring of pain patients. Patients (n = 133) undergoing treatment for chronic pain at four clinics participated in the study and provided paired oral fluid and urine specimens. Oral fluid specimens were collected with Quantisal(TM) saliva collection devices immediately following urine collection. Oral fluid specimens were analyzed for 42 drugs and/or metabolites by validated liquid chromatography-tandem mass spectrometry procedures. Accompanying urine specimens were initially screened by immunoassay and non-negative results were confirmed. Of the 1544 paired tests, 329 (21.3%) drug analytes were positive, and 984 (63.7%) were negative for both specimens resulting in an overall agreement of 85%. There were 83 (5.4%) analyte results that were positive in oral fluid and negative in urine, and 148 (9.6%) were negative in oral fluid and positive in urine for an overall disagreement of 15%. Cohen's Kappa value was 0.64, indicating "substantial" agreement. The primary exceptions to agreement were the lower detection rates for hydromorphone, oxymorphone, and benzodiazepines in oral fluid compared to urine. The authors conclude that, overall, oral fluid tests produced comparable results to urine tests with some minor differences in detection rates for different drug classes.

Oral fluid drug testing of chronic pain patients. I. Positive prevalence rates of licit and illicit drugs.

Oral fluid compliance monitoring of chronic pain patients is an analytical challenge because of the limited specimen volume and the number of drugs that require detection. This study evaluated oral fluid for monitoring pain patients and compared results to urine studies of similar populations. Oral fluid specimens were analyzed from 6441 pain patients from 231 pain clinics in 20 states. Specimens were screened with 14 ELISA assays and non-negative specimens were confirmed by LC-MS-MS for 40 licit and illicit drugs and metabolites. There was an 83.9% positive screening rate (n=5401) of which 98.7% (n=5329) were confirmed at ≥ LOQ concentrations for at least one analyte. The prevalence of confirmed positive drug groups was as follows: opiates > oxycodone > benzodiazepines > methadone ≈ carisoprodol > fentanyl > cannabinoids ≈ tramadol > cocaine > amphetamines ≈ propoxyphene ≈ buprenorphine > barbiturates > methamphetamine. Approximately 11.5% of the study population of pain patients apparently used one or more illicit drugs (cannabis, cocaine, methamphetamine and/or MDMA). Overall, the pattern of licit and illicit drugs and metabolites observed in oral fluid paralleled results reported earlier for urine, indicating that oral fluid is a viable option for use in compliance monitoring programs of chronic pain patients.

Urine drug testing of chronic pain patients. IV. prevalence of gabapentin and pregabalin.

Gabapentin and pregabalin are well established for the treatment of seizures and neuropathic pain. Both drugs are eliminated primarily unchanged by renal excretion. As part of an ongoing research program to improve and expand drug testing methods for compliance monitoring of pain patients, the prevalence and concentrations of gabapentin and pregabalin in urine specimens from chronic pain patients were determined by a validated liquid chromatography-tandem mass spectrometry assay. The study was approved by an Institutional Review Board. A total of 57,542 urine specimens from 231 pain clinics located in 19 states were analyzed over the period of November 24, 2009, through May 2010. The limit of quantitation (LOQ) and upper LOQ of the assays for both drugs were 2.5 and 1000 µg/mL, respectively. Gabapentin was identified in 7013 specimens (12.2% prevalence), and pregabalin was identified in 4799 patients (8.3% prevalence). Generally, gabapentin concentrations were more than twofold higher than pregabalin, consistent with their relative potencies. Interestingly, both drugs were found in specimens from 249 patients, likely representing switching of prescriptions by the prescriber.

Urine testing for norcodeine, norhydrocodone, and noroxycodone facilitates interpretation and reduces false negatives.

Urine drug testing of pain patients provides objective information to health specialists regarding patient compliance, diversion, and concurrent illicit drug use. Interpretation of urine test results for semi-synthetic opiates can be difficult because of complex biotransformations of parent drug to metabolites that are also available commercially and may be abused. Normetabolites such as norcodeine, norhydrocodone and noroxycodone are unique metabolites that are not available commercially. Consequently, detection of normetabolite in specimens not containing parent drug, provides conclusive evidence that the parent drug was consumed. The goal of this study was to evaluate the prevalence and patterns of the three normetabolites, norcodeine, norhydrocodone and noroxycodone, in urine specimens of pain patients treated with opiates. Urine specimens were hydrolyzed with beta-glucuronidase and analyzed by a validated liquid chromatography tandem mass spectrometry (LC/MS/MS) assay for the presence of codeine, norcodeine, morphine, hydrocodone, norhydrocodone, hydromorphone, dihydrocodeine, oxycodone, noroxycodone, and oxymorphone. The limit of quantitation (LOQ) for these analytes was 50ng/mL. The study was approved by an Institutional Review Board. Of the total specimens (N=2654) tested, 71.4% (N=1895) were positive (>or=LOQ) for one or more of the analytes. The prevalence (%) of positive results for codeine, hydrocodone and oxycodone was 1.2%, 26.1%, and 36.2%, respectively, and the prevalence of norcodeine, norhydrocodone and noroxycodone was 0.5%, 22.1%, and 31.3%, respectively. For specimens containing normetabolite, the prevalence of norcodeine, norhydrocodone and noroxycodone in the absence of parent drug was 8.6%, 7.8% and 9.4%, respectively. From one-third to two-thirds of these specimens also did not contain other metabolites that could have originated from the parent drug. Consequently, the authors conclude that inclusion of norcodeine, norhydrocodone and noroxycodone is useful in interpretation of opiate drug source and reduces potential false negatives that would occur without tests for these unique metabolites.

Urine drug testing of chronic pain patients. II. Prevalence patterns of prescription opiates and metabolites.

This study of 20,089 urine specimens from chronic pain patients provided a unique opportunity to evaluate the prevalence of prescription opiates and metabolites, assess the usefulness of inclusion of normetabolites in the test panel, and compare opiate and oxycodone screening results to liquid chromatography with tandem mass spectrometry (LC-MS-MS) results. All specimens were screened by an opiate [enzyme-linked immunosorbent assay (ELISA), 100 ng/mL] and oxycodone assay [ELISA, 100 ng/mL or enzyme immunoassay (EIA), 50 ng/mL] and simultaneously tested by LC-MS-MS [limit of quantitation (LOQ) = 50 ng/mL] for 10 opiate analytes (codeine, norcodeine, morphine, hydrocodone, dihydrocodeine, norhydrocodone, hydromorphone, oxycodone, noroxycodone, and oxymorphone). Approximately two-thirds of the specimens were positive for one or more opiate analytes. The number of analytes detected in each specimen varied from 1 to 8 with 3 (34.8%) being most prevalent. Hydrocodone and oxycodone (in combination with metabolites) were most prevalent followed by morphine. Norcodeine was only infrequently detected whereas the prevalence of norhydrocodone and noroxycodone was approximately equal to the prevalence of the parent drug. A substantial number of specimens were identified that contained norhydrocodone (n = 943) or noroxycodone (n = 702) but not the parent drug, thereby establishing their interpretative value as biomarkers of parent drug use. Comparison of the two oxycodone screening assays revealed that the oxycodone ELISA had broader cross-reactivity with opiate analytes, and the oxycodone EIA was more specific for oxycodone. Specimens containing only norhydrocodone were best detected with the opiate ELISA whereas noroxycodone (only) specimens were best detected by the oxycodone EIA.

Urine drug testing of chronic pain patients. III. Normetabolites as biomarkers of synthetic opioid use.

Opioids are important therapeutic agents available to patients with moderate to severe pain. The synthetic opioids, buprenorphine, fentanyl, meperidine, methadone, and propoxyphene have been utilized for decades as analgesics. One of the major biotransformation pathways of these drugs occurs through N-demethylation leading to the formation and excretion of normetabolites. Normetabolites generally exhibit longer half-lives than the parent drug leading to accumulation with prolonged use. As part of continuing research efforts to improve monitoring programs of chronic pain patients undergoing opioid treatment, we evaluated the prevalence and relative abundance of normetabolites of buprenorphine, fentanyl, meperidine, methadone, and propoxyphene in patients? urine specimens. Selected sets of specimens were analyzed without prior immunoassay screening by liquid chromatography-tandem mass spectrometry for buprenorphine, fentanyl, meperidine, methadone, propoxyphene, and their respective normetabolites. Limits of quantitation (LOQ) were as follows: buprenorphine, 1 ng/mL; fentanyl, 0.5 ng/mL; meperidine, 50 ng/mL; methadone, 50 ng/mL; and propoxyphene, 50 ng/mL. LOQs for normetabolites were equal to the parent drug with the exception of norbuprenorphine (2.5 ng/mL). The percentage of positive specimens that contained normetabolite (only) ranged from 8.0% for EDDP (2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine) to 53.1% for norpropoxyphene. Inclusion of the five normetabolites in the test panel produced an increase in detection rates for parent drug use as follows: buprenorphine, 10.0%; fentanyl, 42.1%; meperidine, 98.7%; methadone, 8.7%; and propoxyphene, 113.2%. The authors conclude that testing for synthetic opioid normetabolites enhances the effectiveness of monitoring programs for pain patients.