Correlation of Fentanyl Positive Drug Screens with Other Medications in Patients from Pain, Rehabilitation and Behavioral Programs

Fentanyl has been associated with many drug overdose deaths; its presence in many street drugs has been postulated to be increasing. We examined 1.3 million urine drug tests from April 2016 to April 2019 for fentanyl and other drugs. The highest relationship was observed with heroin. Approximately 30%-40% of the drug tests positive for the heroin metabolite 6-monacetylmorphine (6-MAM) were also positive for fentanyl. There was a large variance over time, but the percent positive in 2016 and 2019 were similar. In contrast, there was a definite increase in the presence of fentanyl with cocaine and methamphetamine. There was not a large increase over time associated with methadone, buprenorphine, and marijuana.

Naloxone Dosing After Opioid Overdose in the Era of Illicitly Manufactured Fentanyl

INTRODUCTION

Illicitly manufactured fentanyl (IMF) is responsible for a growing number of deaths. Some case series have suggested that IMF overdoses require significantly higher naloxone doses than heroin overdoses. Our objective was to determine if the naloxone dose required to treat an opioid overdose is associated with the finding of fentanyl, opiates, or both on urine drug screen (UDS).

METHODS

A retrospective chart review was conducted at a single emergency department and its affiliated emergency medical services (EMS) agency. The charts of all patients who received naloxone through this EMS from 1/1/2017 to 6/15/2018 were reviewed. The study included patients diagnosed with a non-suicidal opioid overdose whose UDS was positive for opiates, fentanyl, or both. Data collected included demographics, vital signs, initial GCS, EMS and ED naloxone administrations, response to treatment, laboratory findings, and ED disposition. The fentanyl-only and fentanyl + opiate groups were compared to the opiate-only group using the stratified (by ED provider) variant of the Mann-Whitney U test.

RESULTS

Eight hundred and thirty-seven charts were reviewed, and 121 subjects were included in the final analysis. The median age of included subjects was 38 years and 75% were male. In the naloxone dose analysis, neither the fentanyl-only (median 0.8 mg, IQR 0.4-1.6; p = 0.68) nor the fentanyl + opiate (median 0.8 mg, IQR 0.4-1.2; p = 0.56) groups differed from the opiate-only group (median 0.58 mg, IQR 0.4-1.6).

CONCLUSION

Our findings refute the notion that high potency synthetic opioids like illicitly manufactured fentanyl require increased doses of naloxone to successfully treat an overdose. There were no significant differences in the dose of naloxone required to treat opioid overdose patients with UDS evidence of exposure to fentanyl, opiates, or both. Further evaluation of naloxone stocking and dosing protocols is needed.

Use of rapid fentanyl test strips among young adults who use drugs

BACKGROUND

The overdose epidemic has been exacerbated by a dramatic increase in deaths involving illicitly manufactured fentanyl (IMF). Drug checking is a novel strategy to identify IMF in illicit drugs. We examined the uptake and acceptability of rapid fentanyl test strips among young adults.

METHODS

From May to September 2017, we recruited 93 young adults in Rhode Island who reported injecting drugs or using heroin, cocaine, or illicitly obtained prescription pills in the past 30 days. Participants were asked to test either their urine after drug use (post-consumption) or a drug sample prior to use (pre-consumption) using rapid fentanyl test strips. After a questionnaire and a brief training, participants received ten strips for their personal use and were asked to return for a one-month follow-up visit, which assessed the uptake and acceptability of the rapid strips tests and the behavioral outcomes associated with receipt of a positive test.

RESULTS

Of the 81 (87%) participants who returned for follow-up and who had complete data, the mean age was 27, 45 (56%) were male, and 37 (46%) were non-white. A total of 62 participants (77%) reported using at least one test strip. Of these, 31 (50%) received at least one positive result. A positive result was associated with older age, homelessness, heroin use, injection drug use, ever witnessing an overdose, and concern about overdose or drugs being laced with fentanyl (all p < 0.05). Receiving a positive result was significantly associated with reporting a positive change in overdose risk behavior between baseline and follow-up (p ≤  0.01). Among all participants, 79 (98%) reported confidence in their ability to use the test strips and 77 (95%) wanted to use them in the future.

CONCLUSIONS

Young adults reported high uptake and acceptability of fentanyl test strips to detect IMF in illicit drugs.

[Intoxication or false-positive acetaminophen result of toxicological determinations? Two case reports]

The aim of this study was to show the diagnostic procedure used in the two cases with false-positive serum acetaminophen results in suspected acetaminophen poisoning. The determination of serum acetaminophen were carried out using a UV/VIS spectrophotometer (Specord 40 Analytik Jena), coupled with an analytic computer station WinASPECT. The employed method of determination was based on the acetaminophen reaction with sodium nitrite, which yields yellow colour of solution in the presence of sodium hydrate. The intensity of the yellow colour depends on the concentration of acetaminophen in serum. The relationship between absorbance and concentration was linear at concentrations in the range 50-600 microg/mL, with relative standard deviation of +/- 2.1% and detection limit of 30 microg/mL. To confirm or reject the doubtful results of colorimetric assays, the serums of patients were measured with high performance liquid chromatography with mass spectrometry detection and gas chromatography with mass spectrometry detection. The analysis of presented cases leads to a conclusion that acetaminophen results should be confirmed either by scanning urine for p-aminophenol presence (which is a routine procedure in our laboratory) or by using a different method of measuring acetaminophen serum levels.

[Acute methoxetamine intoxication--a case report with serum and urine concentrations]

Methoxetamine (MXE) is a novel synthetic drug, structurally related to phencyclidine, with ketamine-like properties. Available in Poland since 2010, with no legal control, is adverti. sed as the "ideal dissociation drug". The aim of this study was to present a case of nasal methoxetamine acute poisoning in a 28-year-old man, the course of treatment, and the method of identification of this substance in serum and urine. In the course of this intoxication extreme agitation and aggression with slight response to benzodiazepines were observed. The patient was confused, hallucinated. In addition, the physical examination re. vealed tachycardia 120/min and normal blood pressure (130/80 mm Hg). The period of acute poisoning was covered by amnesia. The MXE concentrations in serum and urine were determined using liquid chromatography-mass spectrometry (LC-MS-MS) method, and were respectively 270 ng/ml and 660 ng/ml. Confirmed MXE poisoning increases our knowledge about this new substance, providing relevant clinical and analytical data.

[Suicidal intoxication with sodium azide--a case report]

Sodium azide (NaN3) is an inorganic matrix compound with a very high toxicity. Mechanism of action is not clarified, and it is assumed to interfere with the processes of oxidative phosphorylation. The acute intoxications with sodium azide are extremely rare. We described a case of 19-year-old man who was found dead. In the course of prosecution the empty container, with label "NaN3, 20 g", was found near the body. There were traces of white powder detected in the container. Azide ions were determined by derivatization, i.e. they were transformed to pentafluorobenzaldehyde azide compound. Analysis of the final extract after derivatization was performed by gas chromatography coupled with mass spectrometry GC/MS. The largest concentration of azide ions were determined in the stomach content and vitreous humour, and much less one in whole blood, urine and kidney fluid.

[Determinations of the presence of drugs in traffic users in the material of the Department of Forensic Medicine, Medical University of Białystok]

In recent years, there has been observed an increasing number of traffic users being under influence of psychoactive substances that affect the central nervous system. A total of 198 blood samples and 23 urine samples collected from traffic users (drivers, passengers and pedestrians) suspected of having ingested psychoactive substances were examined. The analysis included blood samples collected from living individuals and blood or urine from the deceased. Ethyl alcohol levels were determined by gas chromatography, while body fluids were examined by Elisa tests for determination of cannabinoids, amphetamines, opium narcotics, cocaine (benzoiloecgonine), benzodiazepines, barbiturates and tricyclic antidepressants. The confirmation of positive results was carried out by gas chromatography with mass detector. Twenty-nine blood samples were positive, what constituted 14.6% of the total number of investigated cases, including 12 (7.8%) of samples originating from living individuals and 17 (37.8)--from the fatalities. In both groups, the most commonly detected substances were cannabinoids (THC and its metabolite carboxy-THC) and amphetamines and its analogues.

Evaluation of a urine screen for acetaminophen

BACKGROUND

Acetaminophen (APAP) is a leading cause of fatal overdose. This study examined the performance characteristics of the Biosite Triage TOX Drug Screen qualitative APAP urine test (urine screen) in a clinical setting.

METHODS

Paired urine and serum waste samples (collected within 2 hours of one another) were quantitatively analyzed for APAP concentration and compared to the urine screen results.

RESULTS

A total of 191 paired samples met inclusion criteria. The urine screen did not report a negative result for the 21 samples with a serum APAP concentration of > or =10microg/mL and had a sensitivity of 100% (95% confidence interval [CI], 85-100%). The urine screen had a sensitivity of 96% (95% CI, 91-99%) and a specificity of 90% (95% CI, 82-95%) for detecting urine APAP concentrations > 5microg/mL by gas chromatograph mass spectroscopy (GCMS) methods, and a sensitivity of 81% (95% CI, 73-87%) and a specificity of 95% (95% CI, 85-98%) by high-pressure liquid chromatography (HPLC) methods.

CONCLUSIONS

The urine screen detected urine APAP concentrations with good accuracy and may be an effective screen to rule out acute APAP overdose in some circumstances. Its clinical utility is discussed.

Accuracy of information on substance use recorded in medical charts of patients with intentional drug overdose

Psychoactive substance use is a risk factor for suicidal behavior and current intoxication increases the likelihood of serious intentional drug overdose (IDO). The objective was to assess the accuracy of information on substance use recorded in medical charts using toxicological assays as a reference in subjects admitted for IDO to an emergency department. Patients (n=1190) consecutively admitted for IDO were included. Information on substance use was recorded in routine practice by the emergency staff and toxicological assays (cannabis, opiate, buprenorphine, amphetamine/ecstasy, cocaine, LSD) were carried out in urine samples collected as part of routine management. The information on substance use was recorded in medical charts for 24.4% of subjects. A third of subjects (27.5%) were positive for toxicological assays. Recorded substance use allowed correct classification of nearly 80% of subjects. However, specificity (88.6%) was better than sensitivity (54.2%). Compared with toxicological assays, medical records allowed identification of only half of the subjects with current substance use. The usefulness of systematic toxicological assays during hospitalization for IDO should be assessed in further studies exploring whether such information allows medical management to be modified and contributes to improving prognosis.

[Drug addiction in the medico-legal certification of the Department of Forensic Medicine of Medical University of Gdańsk in the years 1996-2005]

The objective of the study was the presentation of the type and extent of drug addiction in the region covered by the Department of Forensic Medicine of the Medical University of Gdańsk based on the results of analyses of biological samples collected from the living and deceased subjects during the decade from 1996 to 2005. The studies were based on 110 cases of lethal intoxication after psychoactive substances overdosing and 63 cases of living people involved in the infringement of the law. Body-fluids (blood, urine) and post-mortem samples (stomach contents, small intestine contents, liver, kidney, brain and lung tissues) were collected and stored at -20 OC. The screening analysis of urine was performed using the Fluorescence Polarization Immunoassay method (TDx, Abbott) and the enzyme immunoassay method (Syva Rapid Test, Dade Behring). The confirmation of positive results was carried out by thin-layer chromatography (TLC), as well as gas and liquid chromatography with various detectors (GC/FID, GC/NPD, GC/MS, LC/UV-DAD). In the last 10 years, there was noted a 3-fold increase in the number of cases that required an analysis of narcotics content, and in the last 4 years, such cases exceeded 10% of the total number of investigated cases. The number of analyses aiming at determination of amphetamine and cannabinol contents in living people (mainly among individuals that caused traffic accidents) increased. Among deceased subjects, deaths were predominantly caused by intoxication with opiates or combinations of opiates and other narcotic substances and medications. The presence of both ethanol and drugs was detected and confirmed mainly in post-mortem biological materials.

Utility of urine drug screening: A Clinical audit

OBJECTIVE

To assess requesting patterns and clinical utility of urine drug screens (UDS).

METHODS

All UDS requests received between March 2002 and October 2002 were identified. Two trained assessors reviewed case histories and categorized the utility of the UDS and gave a utility score using a Visual Analogue Scale.

RESULTS

Of 171 UDS requested, 67.3% were men. Age range was 15-92 (mean 36) years. In total, 70.8% were received from accident and emergency centre (AEC). Clinical utility was identified in only 85 of 171 UDS. Sixty-one per cent of requests from AEC were defined as having no clinical utility. Twenty-four per cent of requests originating from other specialities were identified as having no clinical utility. Overall, a test was more likely to be of utility if it was requested from non-AEC than from AEC (Pearson's chi(2) two-sided t-test, P < 0.0001). Indications for UDS were toxic ingestion (33.3%), psychosis (15.2%), impaired consciousness (13.5%), behavioural disturbance (4.1%), confusion with HIV infection (3.5%), alleged adulteration (3.5%), seizure (9.4%), cardiac arrest (1.8%) and miscellaneous (15.8%).

CONCLUSIONS

Our data show excessive requesting for UDS in routine overdose, contrary to international guidelines. Requests for UDS originating from AEC are more likely to have no utility than those from other specialities. Availability of point of care UDS might increase use of UDS, but cost-effectiveness and utility must be assessed.

Gamma-hydroxybutyrate serum levels and clinical syndrome after severe overdose

STUDY OBJECTIVE

We discuss a prospective case series of patients who present with a severe gamma-hydroxybutyrate intoxication with confirmatory serum and urine gamma-hydroxybutyrate levels.

METHODS

Patients with a clinical suspicion of gamma-hydroxybutyrate-like drug overdoses and a Glasgow Coma Scale score of 8 or lower were identified from July 1998 through January 1999. Serial serum specimens and a single urine specimen were collected. The levels of gamma-hydroxybutyrate were performed by gas chromatography-mass spectrometry.

RESULTS

All 16 suspected severe gamma-hydroxybutyrate overdose patients had significant serum or urine levels of gamma-hydroxybutyrate. Serum levels ranged from 45 to 295 mg/L, with a median of 180 mg/L (interquartile range [IQR] 235 to 118 mg/L). Patients who developed a Glasgow Coma Scale score of 3 had serum levels that ranged from 72 to 300 mg/L, with a median of 193 mg/L (IQR 242 to 124 mg/L). The time of awakening ranged from 30 minutes to 190 minutes, with a median of 120 minutes (IQR 150 to 83 minutes). Quantitative serum gamma-hydroxybutyrate levels did not correlate with the degree of coma or the time to awakening. Urine levels ranged from 432 to 2,407 mg/L, with a median of 1,263 mg/L (IQR 1,550 to 796 mg/L). Mild transitory hypoventilation occurred in 5 of the 16 patients.

CONCLUSION

All of our patients with clinically suspected severe gamma-hydroxybutyrate overdose were confirmed to have significant serum and urine levels of exogenous gamma-hydroxybutyrate. They presented with severe coma that lasted 1 to 2 hours. Transient hypoventilation occurred in one third of these patients.

1H NMR spectroscopy and GC-MS analysis of alpha-chloralose. Application to two poisoning cases

Alpha-chloralose, a compound widely used as a rodenticide and in the control of bird pests, is readily available. Two cases of intentional poisoning are reported. Both patients became comatose and presented hypersialorrhea and myoclonal crises in the legs. They were discharged from hospital after several days. As clinical signs of alpha-chloralose poisoning lack specificity, anamnesis might be difficult, particularly in the case of delayed diagnosis. Toxicological analysis is therefore critical, and this article reports the investigation of serum and urine samples by gas chromatography-mass spectrometry (GC-MS) in the electron-impact mode, and by 1H nuclear magnetic resonance (1H NMR) spectroscopy. Non-hydrolyzed urinary samples and those hydrolyzed by beta-glucuronidase were taken into consideration. After acetylation, GC-MS analysis was based on characteristic mass-to-charge ratio values of 272 for alpha-chloralose and 206 for beta-hydroxyethyltheophylline, which was used as internal standard. Characterization of alpha-chloralose species by 1H NMR spectroscopy was performed taking two parameters into account: chemical shift and coupling-constant values. Without any pretreatment, 1H NMR spectroscopy revealed the presence of free (5.50 and 6.15 ppm) and conjugated forms of alpha-chloralose by characteristic resonances of H1 and chloral-type protons, respectively. Quantitative analysis was performed by relative integration of peak areas. Serum alpha-chloralose showed concentrations below the quantitation limit of both methods. In urine samples, the free chemical species rapidly decreased. GC-MS analysis revealed the predominence of conjugation after a beta-glucuronidase hydrolysis step. 1H NMR analysis directly showed that on admission of the first patient, average urinary concentrations were 1.73 mmol/L (535 mg/L) for the free form and 13.72 and 6.25 mmol/L for the two conjugated forms. A later enzymatic treatment confirmed the total concentration of alpha-chloralose chemical species. Analysis of alpha-chloralose in urine by either GC-MS or 1H NMR spectroscopy methods proved to be comparable.

Massive Venlafaxine Overdose Resulted in a False Positive Abbott AxSYM®Urine Immunoassay for Phencyclidine

CASE REPORT

A 13-yr-old girl overdosed on 48 x 150 mg venlafaxine (Effexor XR). She was taking venlafaxine regularly for depression. Her only other medications included topical Benzamycin and pyridoxine 50 mg daily for acne. The Abbott AxSYM assay was positive only for phencyclidine, but GC/MS did not confirm the presence of phencyclidine. Toxilab identified only one substance, confirmed by GC/MS as venlafaxine. A serum sample obtained 3 h after her ingestion revealed a venlafaxine concentration of 24460 ng/mL and an O-desmethylvenlafaxine concentration of 3930 ng/mL, confirming the massive acute overdose (therapeutic range of venlafaxine and O-desmethylvenlafaxine together is 250-750 ng/mL). Urine spiked with 4.2 mg/mL ofvenlafaxine and 0.7 mg/mL of O-desmethylvenlafaxine was interpreted as positive with the Abbott AxSYM fluorescent polarized immunoassay for phencyclidine (readout of 28 ng/mL).

CONCLUSION

Venlafaxine may cause a false positive Abbott AxSYM phencyclidine assay when present in very high concentrations. Physicians should be aware of this potential reaction when interpreting urine drug immunoassays.

[Carbamazepine in modern toxicological casuistry at Department of Forensic Medicine of Medical University of Gdańsk in the years 1996-2001]

In this paper the authors presented 20 cases of death of individuals diagnosed at Department of Forensic Medicine of Medical University of Gdańsk in the years 1996-2001. In all cases carbamazepine was found in post-mortem material collected from the deceased during autopsy. 14 deaths resulted from intoxication after overdose of drugs for the purpose of committing suicide. In the other cases carbamazepine did not have on influence on the cause of death. The subject of the chemo-toxicological analysis were blood and urine samples and also specimens of the stomach with its contents, liver, kidney, brain and lung specimens collected during autopsy. TLC, GC-FID, GC-MS, TLC-UV were used as diagnostic tools. Determined carbamazepine concentrations fluctuated between 1.5 to 78.6 micrograms/ml in the blood.

Urine drug screening in the medical setting

BACKGROUND

The term drug screen is a misnomer since it implies screening for all drugs, which is not possible. Current practice is to limit the testing to the examination of serum for several drugs such as ethanol, acetaminophen, salicylate, and of urine for several specific drugs or classes of drugs. In the emergency setting the screen should be performed in less than one hour. Controversies continue to exist regarding the value of urine drug testing in the medical setting. The reasons for these include the drugs involved, the sample, the methods utilized to perform the tests, and the level of understanding of the physician using the data, all of which are closely related to the other.

METHODS

Current automated methods provide rapid results demanded in emergency situations, but are often designed for, or adapted from, workplace testing and are not necessarily optimized for clinical applications. Furthermore, the use of these methods without consideration of the frequency in which the drugs are found in a given area is not cost-effective. The laboratory must understand the limitations of the assays used and provide this information to the physician. Additionally, the laboratory and the physicians using the data must cooperate to determine which drugs are appropriate and necessary to measure for their institution and clinical setting. In doing so it should be remembered that for many drugs, the sample, urine, contains the end product(s) of drug metabolism, not the parent drug. Furthermore, it is necessary to understand the pharmacokinetic parameters of the drug of interest when interpreting data. Finally, while testing for some drugs may not appear cost-effective, the prevention or reduction of morbidity and mortality may offset any laboratory costs.

CONCLUSIONS

While the literature is replete with studies concerning new methods and a few regarding physician understanding, there are none that we could find that thoroughly, objectively, and fully addressed the issues of utility and cost-effectiveness.

Urine drug screens in overdose patients do not contribute to immediate clinical management

A prospective study assessed whether routine urine drug screens might alter the management of overdose patients. Urine was collected from 107 patients with a diagnosis of deliberate self-poisoning seen in the emergency department (ED) of a teaching hospital. The mean age of patients was 36 years (range 13-86 years) and 64% were female. All patients recovered after standard investigations and management, which did not include knowledge of urinary drug screen results. Two hundred ninety-seven compounds were detected in the 107 urine samples. Twenty percent were drugs administered in the ED. Sixty-five percent of patients were found to have taken more than one drug. Benzodiazepines were detected in 18% of samples, paracetamol in 10%, and alcohol in 8%. Sixty-one drugs, in 35 people, were identified that the patients did not report taking. Of these, paracetamol (10), benzodiazepines (9), and tetrahydrocannabinol (8) were the most common. All patients in whom paracetamol was found had already had paracetamol detected in blood and appropriate management instituted. If the results of urine screening had been immediately available this would not have affected the management or outcome of any patient.

Identification of drugs ingested in acute poisoning: correlation of patient history with drug analyses

The aim of this study was to assess the reliability of patient history in the identification of the drugs taken by patients who have an acute drug overdose. To this end, a prospective study involving 51 cases of acute, deliberate drug poisoning was carried out (patients with ethanol as the only apparent cause of intoxication were excluded). Information based on interviews with the patients and their companions or on circumstantial evidence (e.g., drug containers found) was compared with the results from drug analyses of various body fluids. The information obtained on admission was completely in accordance with the laboratory findings in only 27% of the cases. Minor discrepancies between the history and the results from drug analyses concerning the identity of the drugs taken were found in 55% of the cases. In 18% of the cases, the discrepancies were considered clinically important. Serious symptoms occurred in approximately 20% of the patients, but none of them were the result of incorrect information obtained on admission. All the patients survived. These results support the prevailing view that rapid identification of the drugs taken in overdose by means of comprehensive drug screens would have little effect on the treatment of most cases of acute poisoning. However, such assays would enable optimal treatment of many cases of acute poisoning by reducing the need for supervision and costly treatments and facilitating the identification of cases that would require prompt drug-specific treatment.

The use of nuclear magnetic resonance spectroscopy in the detection of drug intoxication

The use of nuclear magnetic resonance (NMR) spectroscopy as a method for drug analysis has the advantages of reduced pre-analytical preparation time and the potential to detect and quantitate drug conjugates and metabolites simultaneously. NMR was investigated as a method to screen for organic substances (and metabolites) in 25 patients who presented to the Emergency Department with clinical indications of a drug overdose. Urine specimens were examined by 1H NMR spectroscopy at 300 MHz and the results compared with gas chromatography-mass spectrometry (GC-MS) results. There was a 56% concordance (14 of 25 samples) between NMR and GC-MS. NMR identified acetaminophen, ibuprofen, aspirin, valproate, carbamazepine, and pseudoephedrine as parent compounds or metabolites. For a patient for whom GC-MS results were negative, NMR strongly suggested the presence of erythromycin. NMR was most successful in identifying analgesics and antiepileptic drugs (sensitivity 83-100%). In 10 patients, signals from 1,2-propanediol, a common vehicle for some pediatric medications, were observed by NMR spectroscopy. NMR had 0% sensitivity in identifying tricyclic antidepressants and antipsychotic drugs. In these samples, GC-MS detected a variety of compounds, including tricyclic antidepressants and their metabolites and chlorpromazine. In addition, other substances that had not been disclosed as having been ingested, such as caffeine, diphenhydramine, and nicotine, were detected by GC-MS. NMR spectroscopy represents an emerging supplementary analytical technique that is applicable to a wide range of possible intoxicants and to the evaluation of the intoxicated patient, particularly when larger amounts of the intoxicant (> 200 mg) are ingested.

Predictive properties of a qualitative urine acetaminophen screen in patients with self-poisoning

OBJECTIVE

Screening for acetaminophen toxicity is recommended in almost all cases of self poisoning. We compared a qualitative urine acetaminophen screen to the quantitative serum acetaminophen to test the hypothesis that a negative urine acetaminophen screen would be predictive of a negative serum acetaminophen level.

METHODS

All adults with intentional ingestions evaluated in our Emergency Department during 1995 were retrospectively identified based on Emergency Department International Classification of Disease--9th edition codes. Laboratory data from each patient including serum and urine toxicologic assays were examined. Predictive properties of urine acetaminophen screens for serum acetaminophen were evaluated.

RESULTS

A total of 88 patients were identified who had both a serum acetaminophen and a urine acetaminophen performed. The sensitivity of the urine acetaminophen screen was 100% (95% CI 72-100%) and the specificity was 87% (95% CI 80-95%). All patients with negative urine acetaminophen screens had negative serum acetaminophen levels (negative predictive value 100%; 95% CI 96-100%). Accuracy of the urine acetaminophen screen was 89%.

CONCLUSION

A negative urine acetaminophen screen was highly predictive of negative serum acetaminophen levels. It is possible that negative urine acetaminophen screens may obviate the need for 4-hour quantitative serum levels. Further validation in a prospective study is needed.

Tetrahydropalmatine poisoning: diagnoses of nine adult overdoses based on toxicology screens by HPLC with diode-array detection and gas chromatography-mass spectrometry

BACKGROUND

Tetrahydropalmatine (THP) is a neuroactive alkaloid with analgesic and hypnotic action. Its analysis is important because cases of human poisonings have emerged as a result of unregulated use of some proprietary biopharmaceuticals containing purified THP.

METHODS

We established analytical parameters for HPLC with diode-array detection (HPLC-DAD) and gas chromatography-mass spectrometry (GC-MS) for the detection of THP in serum and urine. Nine acutely THP-poisoned adults were thus screened over 16 months.

RESULTS

All patients recovered quickly after mild neurological disturbance. In general, THP was metabolized rapidly and excreted as polar metabolites in urine. Serum THP was measured in five cases and found to be <0.1-1.2 mg/L (<0.3-3.4 micromol/L). Paired analyses of urine with and without glucuronidase treatment clarified the disposition of THP. Our GC-MS method with trimethylsilane derivatization identified O-desmethyl metabolites. With a uniform solid-phase extraction, the HPLC-DAD procedure detected intact glucuronide metabolites.

CONCLUSION

Intact glucuronide metabolites of THP are sensitive markers for THP exposures. Our methods and findings provide practical tools and information for surveillance of intoxication caused by excessive THP intake.

Olanzapine-related fatality

A 43-year-old male psychiatric outpatient died within hours of ingesting as much as 600 mg of olanzapine, a newer antipsychotic agent related to clozapine. Analysis of postmortem blood and urine by gas chromatography with nitrogen-selective detection yielded olanzapine concentrations of 1238 and 6987 micrograms/L, respectively, greatly in excess of levels expected following therapeutic administration of the drug. Based on the toxicology findings, the decedent's known history of suicide attempts, and the circumstances surrounding the death, this case was ruled a suicide by olanzapine overdosage.

Standards of laboratory practice: analgesic drug monitoring. National Academy of Clinical Biochemistry

Analgesics are the most commonly consumed over-the-counter preparations in the United States. They are used in the treatment of various pain syndromes and other medical conditions. Although analgesics are generally perceived to be safe agents, serious toxicity may occur in the setting of acute overdose, chronic abuse, or overuse. The indications for therapeutic drug monitoring in patients using these medications appropriately is as yet not well defined. The emphasis of this discussion, therefore, is on recommendations for monitoring in situations where toxicity is suspected. Preanalytical, analytical, and practice issues including drug interactions, frequency of monitoring, pertinent ancillary tests, reporting, and special patient groups at risk for toxicity are reviewed. Recent information from a major manufacturer of evacuated tubes arguing against the use of gel tubes for blood collection for drug monitoring is included. Colorimetric/enzymatic/immunoassays for the routine/stat monitoring of acetaminophen and salicylate and diflunisal cross-reactivity with most of the currently used salicylate assays are presented. Achiral and chiral chromatographic assays and newly introduced columns such as restricted access media and/or automated chromatographic systems are reviewed for the analysis of ibuprofen, naproxen, and the recently introduced tramadol. Finally, concepts regarding future directions including drug chirality and chiral analysis are presented.

Identification and determination of opipramol metabolites in plasma and urine

In six cases of suspected opipramol overdose, commercially available immunoassays for tricyclic antidepressants (TCA) EMIT tox serum Assay and ADxR serum TCA Assay indicated arbitrarily high or toxic TCA concentrations. However, opipramol concentrations determined by high-performance liquid chromatography (HPLC) analysis were in the high-normal or low-toxic range. This finding prompted us to study opipramol metabolism by mass spectral techniques and to determine the cross-reactivity of opipramol and its metabolites in immunoassays. Three previously unknown metabolites (I, II, V) included an oxidation product of the hydroxyethyl moiety to an acetic acid group at the piperazine side chain (1), a decarboxylation product of the latter metabolite (II), and opipramol-N-oxide (V). In addition, two previously reported metabolites were identified, which included a deshydroxyethyl metabolite (III) and dibenzazepine (IV). One of the major metabolites of opipramol is the acetic acid metabolite (I), which may exceed the opipramol plasma concentration immensely and contribute to an arbitrarily high concentration in commercially available immunoassays. The cross-reactivities of the metabolite (I) were determined to be 64 and 66% with EMIT and ADx, respectively.

Drug screening of patients who deliberately harm themselves admitted to the emergency department

This study was a retrospective analysis of drugs present in blood and urine samples taken from patients (n = 200) admitted to the emergency department of a major teaching hospital with a provisional diagnosis of deliberate self-harm. The aim was to assess the current limited drug screening strategy to see whether it needed to be changed in any way. Drugs present in blood and urine were identified by immunoassay or chromatography, categorized, and concentration-toxicity effects evaluated when practicable. For each case, the various drugs/drug classes detected were correlated with those reported by the patient. A questionnaire evaluation of doctor's perceptions of the influence of the primary blood drug screen on patient destinations was administered. The rapid primary drug screen using a blood/plasma sample detected some 46% of all drugs identified. The doctors considered that it was influential in deciding on immediate patient destination, and therefore, it is likely to be a cost-effective measure. In addition, the screen detected toxic concentrations of drugs in a significant proportion of patients who did not report their ingestion correctly. A primary drug screen using a urine sample detected opiates, cannabinoids, and amphetamines but such detection was considered unlikely to alter short-term treatment. A high-performance liquid chromatography and gas chromatography-mass spectroscopy secondary screen using blood and urine detected a significant number of additional drugs, but was slow, costly, and not likely to alter short-term treatment. The authors conclude that the primary screen for alcohol, benzodiazepines, paracetamol, salicylate, and tricyclic antidepressants remains the optimal drug screening strategy. Quantitative or qualitative estimation of patient-reported drugs such as quinine, theophylline, verapamil, and antiepileptics may be justifiable in individual patients.

A cluster of fentanyl-related deaths among drug addicts in Sweden

During a 16-month period, nine fatalities occurred among white male drug-addicts, where fentanyl was detected at postmortem toxicological analysis. The street samples associated with these cases confirmed the presence of fentanyl as an additive in low-concentration amphetamine powders with caffeine, phenazone and sugar as cutting agents. In seven of the cases, an acute intoxication by fentanyl was considered to be the immediate cause of death, and in one case, it was likely, but no analysis of fentanyl was performed in blood, and in another case the death was suicide by hanging. This appears to be the first report of a cluster of fentanyl-related deaths outside the United States, and the occurrence of fentanyl in combination with amphetamine has not previously been reported. In addition, in all cases, femoral blood was collected, and samples were handled and analysed according to standardized, quality-controlled procedures. The previous history, circumstances surrounding the death, autopsy findings, histology and toxicology examination of each case are presented. The gas chromatographic-mass spectrometric method for fentanyl is also described. Fentanyl concentrations ranged from 0.5 to 17 ng g-1 blood, and from 5 to 160 ng ml-1 urine. Other drugs found were amphetamine (8 cases), ethanol (5 cases) and benzodiazepines (5 cases). Morphine was found in only one case. The average age of men was 33.9 years (range 22-44); six were found in their own of friend's apartment, two inside buildings (stairways) and one was found outdoors. We conclude that fentanyl is a dangerous substance that should be considered in drug-addict deaths even outside the United States, particularly when the remaining toxicology is unremarkable, and the cause of death cannot be ascertained

Measurement of total phospholipids in urine of patients treated with gentamicin

AIMS

The excretion of phospholipids in urine may be a marker of the early renal toxicity of the aminoglycoside antibiotics. Urinary phospholipids are formed in myeloid bodies which develop in the lysosomes of proximal tubules during treatment with the aminoglycosides, and overflow into the urine.

METHODS

Published assays were modified in order to measure the total phospholipid concentrations in human urine. Phospholipids were extracted from freeze-dried urine samples, digested in concentrated sulphuric acid, and the inorganic phosphorus content determined by complexing with ammonium molybdate and measuring the absorbance at 820 nm. Ten septicaemic patients treated with gentamicin for 5-7 days had significantly higher urine phospholipid concentrations than 10 healthy untreated control subjects (P < 0.0001). There was a negative linear relationship between phospholipid excretion and creatinine clearance (r2 = 0.71).

RESULTS

In 34 patients with acute pyelonephritis, increased phospholipid concentrations were observed prior to treatment compared with healthy controls (P < 0.001) and did not alter during treatment with gentamicin. However, the phospholipid concentrations decreased significantly after treatment was completed (P < 0.03).

CONCLUSIONS

These studies suggest that urinary phospholipids may indicate early aminoglycoside toxicity but with poor specificity, as many of the infections being treated may themselves be associated with phospholipiduria.

Quantification of dextropropoxyphene and its metabolite by HPLC in hair of overdose cases

Hair samples taken from 11 persons suspected to have died from an overdose of legal or illicit drugs were analysed. These hair samples were selected, because classical post-mortem toxicological investigations in blood revealed the presence of dextropropoxyphene (PPX) and its major metabolite norpropoxyphene (NPPX). For the hair analysis, hair strands were cut into segments of about 3 cm, washed with water and acetone, dried and pulverised. An aliquot of about 40 mg of those segments was incubated with acetate buffer pH 4.0 and beta-glucuronidase/arylsulfatase. After liquid-liquid extraction with hexane-3-methylbutanol (99:1), drugs were identified and measured by HPLC using piritramide as an internal standard. Preliminary assays showed that the limit of detection for PPX is below 1.0 ng/mg hair, the limit of detection for the metabolite NPPX being significantly higher (1.5 ng/mg). GC/MS, usually the method of choice for this kind of determination, was not chosen, because of the thermolability of PPX and its unspecific mass spectrum. From the hair of 11 persons, 24 segments were prepared and processed. Our results show that ten persons were found positive for PPX; moreover, when regarding the 24 segments, only three were found negative. PPX and NPPX concentrations were detected at maximal concentrations of 26.4 and 71.0 ng/mg hair respectively. Considering the ratio of PPX to NPPX for each person, we found more PPX than NPPX for three persons, whereas for seven persons we found more of the metabolite than its parent drug.

Comparison of oral iron chelator L1 and desferrioxamine in iron-loaded patients

The efficacy of the oral iron chelator 1,2-dimethyl-3-hydroxypyrid-4-one (L1) was compared with that of subcutaneous desferrioxamine in 26 patients with transfusional iron overload. Immediately after red-cell transfusion, 20 patients were randomised to receive either desferrioxamine (50 mg/kg daily as a 12 h subcutaneous infusion), or L1 (50 mg/kg daily by mouth). Patients were evaluated during treatment with the other drug after transfusion the next month. Mean (SD) daily urinary iron excretion was lower during L1 than during desferrioxamine (12.3 [6.7] vs 18.2 [15.3] mg/day). In 5 patients the dose of L1 was raised from 50 to 75 mg/kg daily; mean urinary iron excretion rose from 13.8 (7.0) mg/day to 26.7 (17.8) mg/day, comparable with that during desferrioxamine (24.9 [24.3] mg/day). Faecal iron excretion rose slightly over baseline in 6 patients studied during L1 administration (from 8.5 [0.9] mg/day to 12.2 [0.9] mg/day). Pharmacokinetic studies showed an elimination half-life for L1 of 117-237 min. Studies in dogs and in volunteers showed no absorption of the L1-iron complex, excluding a contribution of absorption of intraluminal complexes of L1 and food iron to urinary iron excretion. Further animal toxicity testing is needed before L1 can be studied in a broader group of patients.