Drug testing in children with excessive daytime sleepiness during multiple sleep latency testing.

STUDY OBJECTIVE: To determine the incidence of positive drug screens in children undergoing a multiple sleep latency test (MSLT) for evaluation of excessive daytime sleepiness (EDS). METHODS: A retrospective analysis was performed in children evaluated at the Boston Children's Hospital Sleep Center between 1998 and 2013 who underwent MSLT for EDS with a concurrent urine and/or serum drug screen. RESULTS: A total of 210 MSLTs were accompanied by drug testing. Children were 12.7 ± 3.7 years old (mean ± SD), 43% were female, and 24% had narcolepsy. Positive tests were obtained in 32% for caffeine, 5% for prescription medications, and 4% for over-the-counter drugs. No drugs of abuse were identified. Children testing positive for caffeine were older (13.8 ± 3.5 vs. 12.4 ± 3.7) and more likely female (59% vs. 36%), but did not differ in MSLT or overnight polysomnographic parameters compared to children without caffeine detected. Overall, only 14% had specific documentation regarding caffeine intake, though 90% were referred from a sleep clinic. Of the children testing positive for caffeine, 5% acknowledged use, 3% denied use, and 92% did not have a documented caffeine intake history during their sleep clinic visit. CONCLUSIONS: Routine drug testing for drugs of abuse during an MSLT for EDS yielded no positive results over a 15-year period, indicating that this routine practice is unnecessary in our pediatric population without specific concerns. However, objective evidence for caffeine exposure was found in 32% of tested children undergoing an MSLT. Sleep physicians rarely documented the caffeine intake history during clinic visits for EDS.

Protein binding of lopinavir and ritonavir during 4 phases of pregnancy: implications for treatment guidelines.

OBJECTIVE: To investigate the intraindividual pharmacokinetics (PKs) of total (protein bound plus unbound) and unbound lopinavir/ritonavir (LPV/RTV) and to assess whether the pediatric formulation (100 mg/25 mg) can overcome any pregnancy-associated changes. DESIGN: Prospective longitudinal PK study. METHODS: HIV-infected pregnant antiretroviral therapy-naive and experienced women receiving LPV/RTV 400 mg/100 mg tablets twice daily. Intensive PK evaluations were performed at 20-24 weeks (PK1), 30 weeks (PK2) followed by empiric dose increase using the pediatric formulation (100 mg/25 mg twice daily), 32 weeks (PK3), and 8 weeks postpartum (PK4). RESULTS: Twelve women completed prespecified PK evaluations. Median (range) age was 28 (18-35) years and baseline BMI was 32 (19-41) kg/m. During pregnancy, total area under the time concentration (AUC0-12h) for LPV was significantly lower than postpartum (PK1, PK2, or PK3 vs. PK4, P = 0.005). Protein-unbound LPV AUC0-12h remained unchanged during pregnancy [PK1: 1.6 (1.3-1.9) vs. PK2: 1.6 (1.3-1.9) µg·h/mL, P = 0.4] despite a 25% dose increase [PK2 vs. PK3: 1.8 (1.3-2.1) µg·h/mL, P = 0.5]. Protein-unbound LPV predose concentrations (C12h) did not significantly change despite dose increase [PK2: 0.10 (0.08-0.15) vs. PK3: 0.12 (0.10-0.15) µg/mL, P = 0.09]. Albumin and LPV AUC0-12h fraction unbound were correlated (rs = 0.3, P = 0.03). CONCLUSIONS: Total LPV exposure was significantly decreased throughout pregnancy despite the increased dose. However, the exposure of unbound LPV did not change significantly regardless of trimester or dose. Predose concentrations of unbound LPV were not affected by the additional dose and were 70-fold greater than the minimum efficacy concentration. These findings suggest dose adjustments may not be necessary in all HIV-infected pregnant women.

Penetration of tenofovir and emtricitabine in mucosal tissues: implications for prevention of HIV-1 transmission.

A mainstay of strategies to prevent HIV-1 transmission is to use antiretroviral therapy (ART) for pre-exposure prophylaxis (PrEP). Critical to the design and interpretation of PrEP prevention trials is the ability to make accurate pharmacological measurements of ART drugs in human genital and colorectal mucosal tissues, the principal route of HIV transmission. Here, we evaluated two drugs that are preferentially used for PrEP: tenofovir (TFV) disoproxil fumarate (TDF) and emtricitabine (FTC). A single oral dose of TDF/FTC (Truvada) was administered to 15 healthy individuals. Over the next 14 days, TFV and FTC were measured in blood plasma and genital secretions using a sensitive assay (lower level of quantification, 0.1 ng/ml). The active intracellular phosphorylated metabolites of these drugs [TFV diphospate (TFV-DP) and FTC triphosphate (FTC-TP)] were measured in homogenates prepared from rectal, vaginal, and cervical tissues. TFV and FTC were detected in blood plasma 14 days after administration of a single dose. The area under the concentration-time curve from 24 hours to 14 days (AUC(1-14d)) for FTC in genital secretions was 27-fold greater than in blood plasma, whereas the AUC(1-14d) for TFV was only 2.5-fold greater in genital secretions than in blood plasma. In rectal tissue, TFV and TFV-DP concentrations were detectable for 14 days and were 100-fold higher than the concentrations in vaginal and cervical tissues. Vaginal and cervical tissue concentrations of FTC were 10- to 15-fold higher than in rectal tissue. Despite high concentrations of FTC in vaginal and cervical tissue, FTC-TP concentrations in all tissue types were detected for only 2 days after dose. The exposure to TFV, TFV-DP, FTC, and FTC-TP was wide ranging depending on the type of mucosal tissue. These results demonstrate the need for detailed pharmacological studies to improve the application of ART for PrEP to prevent transmission of HIV.

Comparison of tissue homogenate analytical results with and without standard addition.

Standard addition (SA) has occasionally been utilized as an analytical tool in forensic toxicology. It is recommended for difficult matrices such as tissue or decomposed specimens in which the accurate quantitation of drug may be problematic. However, the additional preparation time and increased use of specimen may limit its general applicability. In this study, the authors compared SA with direct extraction (DE) and quantitation against a blood calibration curve to assess whether the quantitative results were significantly different. Twenty-two postmortem cases were assayed for drugs such as cocaine and metabolites, opioids, and antidepressants by solid-phase extraction followed by gas chromatography-mass spectrometry operated in the selected ion monitoring mode. A two-tailed, homoscedastic Student's t-test demonstrated that the two sets of data were not statistically different (p = 0.81). In addition, SAs were more likely to demonstrate nonlinearity (r(2) < 0.98).

Comparison of liquid/liquid and solid-phase extraction for alkaline drugs.

The extraction of drugs from biological matrices is an essential specimen preparation step in current forensic postmortem laboratories. Traditionally, liquid/liquid extractions (LLE) were developed and employed to screen for the general unknown. However, solid-phase extractions (SPE) are becoming more popular as the availability of columns with suitable stationary phases increased. The purpose of this work was to determine if switching from an existing LLE to SPE was feasible. The limits of detection (LOD) for 122 drugs and metabolites were determined in blood following SPE and compared to previously determined LOD's by LLE, if available. There were 41 drugs that had LOD's in blood established by both methods; LLE had a lower LOD for 8 drugs (19.5%), SPE had a lower LOD for 16 (39%), and the LOD's were comparable in the remaining drugs. Although SPE cartridges were more expensive than LLE, SPE was determined to be a faster technique and doubled the number of specimens that could be extracted by one analyst within a specific timeframe. The SPE method utilized enabled the detection of several drugs not detectable after LLE (most notably, morphine and benzoylecgonine) and allowed the extraction of weakly acidic and neutral drugs with only one extra step.

Detection of drugs of forensic importance in postmortem bone.

There is a paucity of literature detailing the disposition of drugs in bone and bone marrow. Infrequently, in deaths involving skeletonized remains, fragmentation, decomposition, and exsanguination, traditional specimens may be unavailable for toxicological testing. This study examined the utility of bone for the detection of benzodiazepines, opiates, cocaine and metabolites, and basic drugs in 39 cases. Cases were identified on the basis of a positive blood result. After specimen preparation, samples were assayed by liquid-liquid or solid phase extraction with gas chromatographic and gas chromatographic mass spectrometric detection. The majority of decedents were white males with 28% of individuals between the ages of 41 to 50 years. The cause of death was drug intoxication in 22 cases. The most prevalent drugs detected in the blood males and females were opiates and bases. Morphine, codeine, and oxycodone were detected in bone, whereas 6-acetylmorphine and hydrocodone were absent. For alkaline extractable drugs, in only 57% of blood positive specimens, the corresponding bone was also positive. These included antidepressants and antihistamines. Diazepam and nordiazepam were detected in the bone of all blood positive cases. Bone concentrations were higher than blood levels. Benzoylecgonine was the most common cocaine analyte detected in bone. These data demonstrated that drugs may be detected in bone using current technologies and that in general concentrations were higher than those observed in corresponding blood specimens. A negative result in bone, however, should be interpreted with caution because multiple factors determine the deposition of a drug in this matrix.

Prevalence of dihydrocodeine in hydrocodone positive postmortem specimens.

Hydrocodone (HC) has received renewed interest in the US due to reported increases in opiate related deaths involving psychotherapeutic drugs. The relative contribution of dihydrocodeine (DHC) in these deaths is unknown since little testing of this compound is performed. The objective of the study was to determine the prevalence of DHC in HC positive decedents and report the range of concentrations detected in these cases in order to evaluate the potential role of DHC in the deaths and determine the usefulness of including this analyte in opioid testing protocols. Specimens were assayed by liquid-liquid or solid phase extraction followed by gas chromatography/mass spectrometry operated in the selected ion monitoring mode. A multipoint calibration was utilized in the linear range 2-600ng/mL. Accuracy for HC, DHC and hydromorphone (HM) was 101-106% and between day precision at 160ng/mL between 7% and 11%. One hundred and thirty six cases were identified with the majority male (62%) and white (83%). A search of HC positive cases identified 64 with DHC (47%). The range of HC concentrations was 9-3039ng/mL heart blood (n=43) and 42-12353ng/mL urine (n=21). DHC concentrations in these cases ranged 3-243ng/mL in heart blood and 5-1842ng/mL in urine. DHC/HC ratios ranged 0.00(7)-2.90 in blood (n=43), and 0.01-5.04 in urine (n=21) with 16% and 24% of these cases with ratios >0.50, respectively. HM was detected in only 9 HC cases with the majority positive in urine.

Screening for cocaine metabolite fails to detect an intoxication.

Testing for the presence of cocaine (COC) is common in postmortem and clinical laboratories. COC use may be detected by screening urine specimens for COC metabolite. In the forensic arena, screening positive results are confirmed by a more specific and sensitive technique, such as gas chromatography-mass spectrometry. This article reports the case of an individual who died of COC intoxication but whose immunoassay screen (EMIT) for COC metabolite was negative. Gas chromatography-mass spectrometry analysis of the urine detected benzoylecgonine (BE) at a concentration of 75 ng/mL and COC at 55 ng/mL. These concentrations explain the negative screening result since the cutoff concentration of the assay was 300 ng/mL for BE. The reported cross reactivity with COC was 25,000 ng/mL. However, heart blood concentrations of COC and BE were 18,330 and 8640 ng/mL, respectively. The results from this case provide evidence that an EMIT test alone may fail to detect COC use. Individuals utilizing results of drug screening by immunoassay must be aware of the limitations of this testing methodology.

A comparison of methadone, oxycodone, and hydrocodone related deaths in Northeast Ohio.

Increases in methadone and oxycodone related deaths have been recently documented in the United States. In response to these reports, the authors investigated cases over a six-year period in which postmortem toxicological analyses revealed the presence of methadone, hydrocodone, and oxycodone. The study was designed to determine whether regional methadone-associated mortality in Cuyahoga County reflected national trends and more specifically, to distinguish methadone mortality from other commonly used opioid analgesics. All records of decedents that were found to be positive for methadone, hydrocodone, and/or oxycodone in 1998-2003 were reviewed. The cause and manner of death and demographic information was compiled. The cases were divided into lethal intoxications and cases where a positive result was determined to be an incidental finding. Lethal intoxications as a result of only methadone, hydrocodone, or oxycodone were separated from polydrug intoxications. Thoroughout the study, an increase was observed in the number of positive cases. In contrast to recent national data, although the number of methadone-positive cases increased from 4 in 1998 to 18 in 2003, this did not result in an increase in methadone overdoses [1 death in 1998 (25%) to 4 deaths in 2003 (22%)]. Although the pharmacokinetic profiles differ, methadone, hydrocodone, and oxycodone lethal intoxications equally comprised 28-29% of cases in which these drugs were detected. There was an overlap in the range of blood concentrations observed for the drug-related death groups and the incidental finding groups. However, mean and median concentrations in oxycodone and hydrocodone related deaths were more than two times greater than those in non-drug-related deaths.

Phencyclidine and cannabinoids in vitreous humor.

Vitreous humor (VH) is routinely collected at autopsy for the testing of electrolytes and ethanol. In recent years drugs of abuse have been detected in this specimen. In this study the authors assayed 30 VH samples for phencyclidine (PCP) and 50 specimens for cannabinoids. Specimens were screened by immunoassay and then assayed for PCP by GC-FID and cannabinoids by GC/MS. Eighteen (60%) specimens screened positive for PCP using a cutoff of 25 ng/mL. Quantitative analysis showed PCP concentrations in VH that screened positive ranged 30-290 ng/mL. Corresponding blood concentrations were 50-600 ng/mL. VH PCP concentrations in the 12 cases which screened negative were 40-470 ng/mL. False negative results were probably due to matrix effects. All VH specimens screened for cannabinoids were negative. Ten negative screening specimens assayed by GC/MS yielded 1 11-nor-9-carboxy-delta-9-tetrahydrocannabinol positive result at 2 ng/mL. These data indicated that VH maybe a useful specimen for the detection of PCP but not for cannabinoids.

A study of drug detection in a postmortem pediatric population.

At The Office of the Cuyahoga County Coroner (CCCO), Cleveland, Ohio, it is customary to perform an autopsy and conduct toxicological testing on decedents less than 19 years of age. This study provides a retrospective evaluation of drugs detected in a pediatric postmortem population between the years 1998 and 2002 (n = 730). Demographic information, cause and manner of death, and toxicological results were examined. Blacks comprised 54% of cases, males 59%, and 48% were less than one year of age or stillborn. Forty-two percent of deaths were ruled natural, 27% accident, 13% undetermined, 5% suicide, and 2% homicide. Of the 640 cases subjected to comprehensive testing, 38% of the cases were positive for at least one compound. Resuscitative/treatment drugs were detected most frequently (56% of positive results), followed by illicit drugs (26%), ethanol (11%), carbon monoxide (8%), and antihistamines (6%). Eighty-seven cases contained more than one drug. The deaths of 47 individuals were drug related (6%). In this population, it is recommended that illicit drugs and ethanol are targeted for testing, especially when limited specimens are available for analysis.

Comparison of drug concentrations in postmortem cerebrospinal fluid and blood specimens.

The concentration of drugs and metabolites in cerebrospinal fluid (CSF) and blood were determined in 282 autopsied cases using liquid-liquid extraction techniques and gas chromatographic analyses. All drugs were confirmed in one matrix by gas chromatography-mass spectrometry. CSF/blood ratios were used to compare the two biological fluids. Classes of drugs evaluated in this study included: benzodiazepines, anticonvulsants, sedatives, opioids, antidepressants, anesthetics, and antihistamines. The majority of the drugs tested were readily detected in CSF specimens. The average CSF/blood ratio for most drugs was in the range of 0.05-0.50. Interpretation of these results is difficult because protein binding, half-life, hydrophobic properties, and pKa of a drug, in addition to survival time after drug use, influence the CSF/blood ratio. While CSF specimens do provide a viable alternative testing matrix when blood specimens are not available, they should not be used to estimate blood drug concentrations.

Cocaine and metabolites urinary excretion after controlled smoked administration.

Understanding cocaine and metabolites urinary excretion following smoking is important for interpretation of urine test results in judicial, workplace and treatment settings. In National Institute on Drug Abuse approved studies on a secure research unit, six subjects smoked placebo, 10, 20, and 40 mg cocaine with a precise dose delivery device and six different subjects smoked 42 mg cocaine in a glass pipe. Urine specimens (n = 700) were collected for up to seven days and analyzed for cocaine (COC), benzoylecgonine (BE), ecgonine methylester (EME), m-hydroxybenzoylecgonine (mOHBE), p-hydroxybenzoylecgonine (pOHBE), norbenzoylecgonine (NBE), and ecgonine (EC) by gas chromatography-mass spectrometry. Results (mean +/- SE) for the 40-mg precise delivery doses are as follows: (Table can not be represented) Mean C(max) for all analytes linearly increased with increasing dose. T(max) was not dose-dependent. All metabolites were detected in some subjects within 2 h. EC concentrations were significantly higher after smoked cocaine in a precise delivery coil compared to a glass "crack" pipe.

The prevalence of drugs in carbon monoxide-related deaths: a retrospective study, 2000-2003.

The objective of this study was to review demographic characteristics and drugs detected in carbon monoxide (CO)-related deaths from cases received by the Office of the Cuyahoga County Coroner in Cleveland, Ohio, from 2000-2003. Postmortem reports were reviewed, and decedents for which CO was listed as the cause of death were included. The data were compiled into 3 groups according to the official coroner's verdict as to the manner of death: accident, suicide, and homicide. Included in this study were 122 cases: 84 (69%) accidental, 31 (25%) suicide, and 7 (6%) homicide. Accident decedents were typically white males, aged 40-59 years, residing in Cleveland. Suicide decedents were also middle-aged, white males but residing in the suburbs. Homicide decedents under the age of 6 were characteristically black (N=2), while decedents over the age of 39 were predominately white (N=3). Carboxyhemoglobin (COHb) levels in suicide cases were higher than concentrations measured in accidental deaths. The highest percentage of suicide decedents (36%) had a COHb level>70% saturation, accident decedents (36%) between 50% and 69% saturation, and homicide decedents (71%) below 50% saturation. Ethanol (N=34) was detected in 28% of deaths, and therapeutic and/or abused drugs (N=50) were detected in 41% of deaths. Illicit drugs were detected in 11% of cases (cocaine/metabolites; THC/metabolites), other drug positives were therapeutic medications. The most common drugs detected were antidepressants and antihistamines in suicides and pain medications and antihistamines in accidents.

Homicidal ethylene glycol intoxication: a report of a case.

We report a case of a 75-year-old hypertensive, diabetic man who presented to the emergency room with symptoms and signs of nausea, acute intoxication, significant alteration in mental status with rapid neurologic deterioration, and blunt impact injuries sustained during a recent altercation with a 36-year-old female companion-caretaker. He denied a history of ethanol abuse or other recent toxic ingestion and had not been diagnosed with or treated for depression. Hospital laboratory tests revealed a metabolic acidosis and a negative urine toxicology screen. He was diagnosed with toxic encephalopathy with metabolic acidosis secondary to metformin. Despite treatments including hemodialysis, he expired after approximately 28 hours of hospitalization. A postmortem anatomic examination revealed recent blunt-impact injuries and cardiac and renal pathology. A subsequent histologic examination revealed the presence of calcium oxalate crystals in the kidneys and brain, in addition to cardiac and renal pathology. Comprehensive forensic toxicologic testing was performed on antemortem and postmortem samples and revealed lethal levels of ethylene glycol. The cause of death was as a result of acute intoxication by ethylene glycol with another condition of multiple blunt impacts to the head, trunk, and extremities. The manner of death was ruled as homicide. A trial by jury, involving the female companion-caretaker, resulted in her conviction, and she was sentenced to 23 years to life in prison. In this report, we present an unusual case of homicidal ethylene glycol intoxication in which legal proceedings have occurred.

Qualitative identification of doxacurium and its breakdown products in postmortem fluids by liquid chromatography-tandem mass spectrometry.

During a death investigation at the Office of the Cuyahoga County Coroner in Cleveland, OH, doxacurium became a drug of interest. The Coroner's Office enlisted the aid of the Federal Bureau of Investigation Laboratory for the doxacurium analysis. Following the request, a method for the extraction and qualitative analysis of the drug in biological fluids was developed. The procedure relies on a simple solid-phase extraction procedure followed by qualitative analysis with liquid chromatography-tandem mass spectrometry. During the development of the new analytical procedure, two breakdown products of doxacurium were detected. Structures for these breakdown products are proposed. This procedure was used to analyze heart blood, cerebrospinal fluid, and bile specimens from the decedent. Doxacurium and its breakdown products were identified in all three specimens.