Fentanyl In Urine Research Articles

Analysis of fentanyl in urine by DLLME-GC-MS.

Fentanyl is a synthetic narcotic anesthetic ∼80-100 times more potent than morphine. Owing to the potential for its abuse, the drug may be included in a forensic toxicology work-up, which requires fast, precise and accurate measurements. Here, the stability of fentanyl was assessed when stored at three different temperatures (-20, 4 and 25°C) in synthetic urine. Stability at those three temperatures was demonstrated over 12 weeks upon analysis by gas chromatography-mass spectrometry with a deuterated internal standard (fentanyl-D5) utilizing three different extraction techniques: liquid-liquid extraction (LLE), solid-phase extraction and dispersed liquid-liquid microextraction (DLLME). The DLLME method was then optimized before use in the analysis of fentanyl in urine samples obtained from autopsy cases at the El Paso County Coroner's Office. Accuracy of the DLLME method was assessed by completing spike and recovery studies at three different fortification levels (10, 100 and 250 ng/mL) with excellent recovery (89.9-102.6%). The excellent comparability between DLLME and LLE is demonstrated (Bland-Altman difference plot with a mean difference of 4.9 ng/mL) and the use of this methodology in the analysis of forensically relevant samples is discussed.

A new automated urine fentanyl immunoassay: Technical performance and clinical utility for monitoring fentanyl compliance

BackgroundOpiate and other drugs of abuse screening assays have been available for many years, and successfully utilized for monitoring patient medication compliance and for detecting misuse. However, immunoassays designed to rapidly detect the highly potent synthetic opioid, fentanyl, have not been available. MethodsWe evaluated a new fentanyl homogeneous enzyme immunoassay (HEIA) (Immunalysis Corporation) for its ability to accurately detect fentanyl in 307 urine samples from patients prescribed chronic opioid therapy. Samples were screened by HEIA and confirmed by LC–MS/MS and ELISA for diagnostic comparison. HEIA precision and interference studies were performed. ResultsHEIA diagnostic sensitivity, specificity and accuracy were 97%, 99%, and 99%, respectively, in comparison with LC–MS/MS and ELISA. HEIA detected 37 of the 38 LC–MS/MS positive samples identified in our initial evaluation, including some that contained very low levels of fentanyl, <1ng/ml (<3fmol/l). HEIA showed minimal cross-reactivity with other opioid analgesics and commonly encountered drugs. Interferences by common urine contaminants were negligible, but we observed considerable signal suppression in acidic samples (pH<4.0). ConclusionsThe HEIA urine fentanyl assay allows for rapid and accurate fentanyl detection, illustrating its utility in monitoring fentanyl compliance and abuse.

Development of a homogeneous immunoassay for the detection of fentanyl in urine

Objective Fentanyl is an extremely potent synthetic opioid that is widely used for chronic pain treatment; it is highly addictive and prone to abuse. The objective is to develop a high throughput homogeneous enzyme immunoassay (HEIA) for the rapid detection of fentanyl in human urine. Methods The HEIA is based on an immunoassay format in which both the antibody and enzyme–drug conjugate are in ready-to-use solution. In the absence of the target analyte in the specimen, enzyme-labeled drug conjugate binds to the antibody and results in a decrease of the enzyme (G6PDH) activity; hence there is lower absorbance at 340 nm. If the target analyte is present in the specimen, it competes with the enzyme-labeled drug to bind to limited amount of specific antibody that result in more enzyme activity and yields an increased absorbance at 340 nm. A polyclonal “in-house” antibody was selected that is capable of measuring fentanyl at low concentrations thus the assay detection limit was determined to be 1 ng/mL. The assay was validated with clinical urine specimens that previously confirmed positively or negatively for fentanyl/norfentanyl by LC-MS/MS. Results The intra-day ( n = 20) and inter-day ( n = 100) precision of the assay was less than 1% CV. No interferences from structurally unrelated and commonly ingested drugs were observed at a concentration of 10,000 ng/mL. A total of 209 LC-MS/MS confirmed urine specimens (149 positive and 57 negative samples) were analyzed by HEIA. The sensitivity, specificity, and accuracy values were 99%, 95%, and 98% respectively. Conclusion This paper describes the development of a highly sensitive homogenous enzyme immunoassay for detecting fentanyl in urine at a cut-off concentration of 2 ng/mL.

Fatal Overdose Due to Prescription Fentanyl Patches in a Patient With Sickle Cell/β-Thalassemia and Acute Chest Syndrome

Introduced into clinical practice in the 1960s, the analgesic fentanyl is 100 times more potent than morphine. Various methods of administration exist including the transdermal Duragesic patch system, widely used in chronic pain and palliative care settings. Numerous, often imaginative methods of abuse of fentanyl patches have been reported; the majority of fatal fentanyl overdose cases resulting from deliberate abuse or suicide. We describe the accidental overdose of a young black male with sickle cell/beta-thalassemia who had been using the Duragesic system for almost 2 years.At autopsy the macroscopic findings were of nonspecific opiate overdose with congested heavy lungs. Histopathological examination revealed severe sickling of red blood cells in the lungs (acute chest syndrome). Toxicological examination revealed blood and urine fentanyl levels of 40 microg/L and 400 microg/L (10 fold and 100 fold higher than therapeutic levels). The mast cell tryptase was also significantly elevated at 76 microg/L, (Normal 2-14 microg/L). We discuss the relevance of these findings with regard to the cause of death, and stress the need to consider fentanyl when confronted with nonspecific signs of opiate overdose as it is not detected in routine toxicological drug screens.

Evaluation of the Coat-A-Count 125I Fentanyl RIA: Comparison of 125I RIA and GC/MS-SIM for Quantification of Fentanyl in Case Urine Specimens

The Coat-A-Count solid phase 125I Fentanyl Radioimmunoassay was evaluated with respect to linearity and precision using equine urine fortified with fentanyl and then compared with a gas chromatographic/mass spectrometric method for quantification of fentanyl in urine. The RIA assay was found to be linear over the urine fentanyl concentration range of 0.25 to 7.5 ng/mL and precise with coefficients of variation (CV) ranging from 9.6 to 19.3%. The RIA calibrators, ranging in fentanyl concentrations from 0.25 to 7.5 ng/mL, and controls, at mean fentanyl concentrations of 0.46 and 1.32 ng/mL, were compared by both the RIA and GC/MS methods. The cross-reactivity with the 125I RIA test was determined for the fentanyl metabolites, norfentanyl and hydroxyfentanyl, and found to be 5% and 35%, respectively. The illicit fentanyl analogs were found to show significant cross-reactivity, ranging from 20 to 100%. The 125I RIA was compared to GC/MS quantifications of fentanyl in 35 positive and 20 negative case urine specimens.

A brief technical communication: Detection of fentanyl in urine

A reliable and sensitive method to analyze fentanyl in urine was developed using radioimmunoassay (RIA). Fentanyl, a highly lipophilic drug (pK a 7.7), has become a common drug of abuse. We evaluated three analytical techniques to detect fentanyl in urine. This paper reports the best of the three — a modified solvent extraction combined with a fentanyl RIA.

ELISA detection of fentanyl in horse urine and plasma.

The prototype of a commercial ELISA test kit designed for fentanyl determination in human urine has been evaluated for screening fentanyl in horse urine and plasma. The measurement of fentanyl after intravenous (2 mg) and intramuscular (0.25 mg) administration in undiluted plasma was not reproducible while accurate quantification of fentanyl in urine greatly depends on the composition of the horse urine. The ELISA assay, however, is simple and could be successfully used for quantitative measurements in diluted urine and for rapid qualitative screening for fentanyl in large numbers of urine samples.

A method to increase recovery of fentanyl from urine.

Fentanyl, a highly lipophilic drug (pk(a) 7.7), is a common drug of abuse. The current standard techniques to detect fentanyl in urine have low recovery rates and poor sensitivity. We report a modified solvent extraction technique that can recover between 63 and 86% of the drug with a detection limit of 0.2 ng/10 ml of urine. In addition, we report the duration of urinary fentanyl excretion in 11 adolescent patients administered either low (less than 10 mg/kg) or high (20-40 mg/kg) doses of fentanyl as part of anesthesia. The mean duration of urinary fentanyl excretion was similar in the two groups, with duration ranging from 1 to 5 days, and urine fentanyl concentration ranging from 0.1 ng to 10.3 ng/10 ml of urine.