Second-hand exposure to aerosolized intravenous anesthetics propofol and fentanyl may cause sensitization and subsequent opiate addiction among anesthesiologists and surgeons

We hypothesize that aerosolization of anesthetics administered intravenously to patients in the operating room may be an unintended source of exposure to physicians. This may lead to inadvertent sensitization, which is associated with an increased risk for developing addiction. This may contribute to the over-representation of certain specialties among physicians with addiction. We retrospectively reviewed the de-identified demographic information of all licensed physicians treated for substance abuse in the State of Florida since 1980, to determine if medical specialty was associated with addiction in this group of individuals. Then, to identify the potential for exposure, two mass spectrometry assays were developed to detect two intravenously administered drugs, fentanyl and propofol, in air. Since 1980, 7.6% of licensed Florida physicians underwent treatment for addiction. Addiction in anesthesiologists was higher than expected. Opiate abuse was greater in anesthesiologists and surgeons compared to other specialties. Aerosolized fentanyl was detected in the air of the cardiothoracic operating room, in patients' expiratory circuits, and in the headspace above sharps boxes, but not in adjoining hallways. Aerosolized propofol was detected in the expirations of a patient undergoing transurethral prostatectomy. While access and stress may place anesthesiologists and surgeons at greater risk for substance abuse, an additional risk factor may be unintended occupational exposure to addictive drugs. This report provides preliminary evidence of detection of aerosolized intravenous anesthetics using two newly developed analytical methods. We conclude that the potential exists for chronic exposure to low levels of airborne intravenously administered drugs. Further studies are under way to determine the significance of this exposure.

Use of gas chromatography/mass spectrometry with positive chemical ionization for the determination of opiates in human oral fluid

An analytical method for the simultaneous determination of codeine, morphine and 6-acetylmorphine (6AM) in human oral fluid was developed. The method involves liquid-liquid extraction in Toxitubes A, derivatization with 99:1 (v/v) N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA)/trimethylchlorosilane (TMCS), and gas chromatography/mass spectrometry with positive chemical ionization (GC/PCI-MS) determination. The detector response was linear over the concentration range 30-500 ng/mL with coefficients of correlation higher than 0.99. The precision was acceptable with coefficients of variation less than 7.5%. The limits of detection achieved were 0.7 ng/mL for codeine, 2.0 ng/mL for morphine, and 0.6 ng/mL for 6AM. The method proposed was applied to 80 oral fluid samples from opiates users, 98% of which were positive for the three analytes. Human oral fluid is a suitable biological fluid for the determination of opiates by GC/PCI-MS.

Potentials of ion trap collisional spectrometry for liquid chromatography/electrospray ionization tandem mass spectrometry determination of buprenorphine and nor-buprenorphine in urine, blood and hair samples

A liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) method has been developed for the analysis of buprenorphine (BUP) and nor-buprenorphine (NBUP) in biological fluids. Analytes are isolated from urine and blood, after addition of d4-buprenorphine (d4-BUP) as internal standard, by solid-phase extraction. Preparation of hair involves external decontamination, mechanical pulverization, overnight incubation in acidic medium, and neutralization prior to extraction. Enzymatic hydrolysis with beta-glucuronidase may be performed to distinguish between free and total BUP. Chromatographic separation is accomplished by gradient elution on a cyanopropyl 2.1 x 150 mm column. Positive ion ESI and MS analyses are carried out in an ion trap mass spectrometer. The use of this mass analyzer allows effective collisional experiments to be performed on ESI-generated MH+ species. Abundant product ions are produced, which can be monitored together with precursor ions without losing sensitivity. Thus, assay selectivity is definitely increased with respect to LC/ESI-MS/MS methods in which only precursor ions are monitored. The method has good linearity (calibration curves were linear in the range 0.1-10 ng/mL in urine and blood, in the range 10-160 pg/mg in hair) and limits of detection of 0.05 ng/mL for both BUP and NBUP in blood and urine samples, of 4 pg/mg for both analytes in hair. Both intra- and inter-assay precision and accuracy were satisfactory at three concentrations studied: relative standard deviations were <13.7% in urine, <17.3% in blood, <17.8% in hair; percent deviation of the mean from the true value was always <10.5% in urine and blood, <16.1% in hair. The method can be used to determine both analytes in the urine and hair of drug addicts on replacement therapy, and in post-mortem blood specimens when there is suspicion of drug-related death.

Simple and sensitive determination of free and total morphine in human liver and kidney using gas chromatography-mass spectrometry

We developed a reliable, simple and sensitive method to determine free and total morphine in human liver and kidney, using gas chromatography-mass spectrometry (GC-MS). Free morphine or total morphine obtained by acid hydrolysis from 0.2g tissue sample was extracted using an Extrelut NT column with an internal standard, dihydrocodeine, followed by trimethylsilylation. The derivatized extract was submitted to GC-MS analysis of EI-SIM mode. The calibration curves of morphine in both liver and kidney samples were linear in the concentration range from 0.005 to 5 microg/g. The lower limits of detection of morphine were 0.005 microg/g. This method proved successful when we determined free and total morphine in liver and kidney obtained from an autopsied man who was mis-ingested morphine compound in the hospital, which resulted in the cause of death being morphine intoxication.

Liquid chromatography–mass spectrometric analysis of buprenorphine and its N-dealkylated metabolite norbuprenorphine in rat brain tissue and plasma

INTRODUCTION

A specific, accurate, and reproducible liquid chromatography-mass spectrometric (LC/MS) method was developed and validated that allows simultaneous measurement of the centrally acting analgesic buprenorphine and its major metabolite, norbuprenorphine, in rat brain and plasma samples.

METHODS

A 96-well plate solid phase extraction (SPE) procedure was developed for buprenorphine and norbuprenorphine using mixed-mode cation-exchange reversed-phase sorbent. An LC method using a C8 column with isocratic mobile phase (80:20 water/acetonitrile with 20 mM ammonium acetate and 0.1% acetic acid) was developed for reproducible and selective separation. A quadrupole mass spectrometer with atmospheric electrospray ionization source under positive ion mode was used for detection. d4-Buprenorphine and d3-norbuprenorphine were used as internal standards.

RESULTS

The calibration curves for buprenorphine and norbuprenorphine in plasma and brain tissue were linear within the range of 7 to 8333 ng/ml (plasma) and 5 to 5000 ng/g (brain). The lower limit of quantification for both buprenorphine and norbuprenorphine from brain tissue was 5 ng/g, and from plasma was 7 ng/ml. Assay accuracy and precision of back-calculated standards were within +/-15%.

DISCUSSION

This method will be useful for investigation of buprenorphine's mechanism of action and clinical profile.

Remifentanil for sedation and analgesia in a preterm neonate with respiratory distress syndrome

We present the efficacy and safety of the use of remifentanil for intubation, sedation and analgesia in a preterm infant during mechanical ventilation for respiratory distress syndrome. A 34-week-old baby, born by cesarean delivery that developed respiratory distress, required intubation and ventilatory support. For intubation, the baby was given midazolam (0.2 mg.kg(-1)) and remifentanil (1 microg.kg(-1)). The intubation conditions were assessed and classified as excellent. The remifentanil infusion was started at dose 0.75 microg.kg(-1).min(-1) and the dose adjustments were made depending on the neonatal infant pain scale (NIPS), hemodynamic and respiratory changes or the presence of spontaneous movements. Pulse oximetry, respiratory rate, ECG and invasive blood pressure were continuously monitored. He was given surfactant within 2.5 h of life after which ventilator parameters could be progressively decreased. Three hours later, the remifentanil infusion was decreased to 0.5 microg.kg(-1).min(-1), and he remained sedated (NIPS < 2). Six hour after surfactant administration, blood gases and chest X ray were normal. The remifentanil infusion was then discontinued and 30 min later the baby was awake and extubated with success. There were no side effects after intubation or during the continuous infusion. The profile of remifentanil allowing a rapid recovery, the absence of side effects and a good level of sedation and analgesia support the choice of this opioid for sedation in the NICU.

Pharmaceutical heroin for inhalation: Thermal analysis and recovery experiments after volatilisation

Pharmaceutical heroin for inhalation was developed for a clinical trial on co-prescription of heroin and methadone to chronic treatment-resistant heroin addicts. Diacetylmorphine base was selected as the active pharmaceutical ingredient for this product with caffeine anhydrate added as an excipient. Differential scanning calorimetry and thermogravimetric analysis showed that addition of caffeine resulted in a lower melting temperature and a higher volatilisation rate for the mixture than for diacetylmorphine base alone. Recovery experiments showed that 40.8+/-5.3% of diacetylmorphine base could be found in smoke condensate after volatilisation of diacetylmorphine-caffeine tablets. All of the caffeine from each tablet was recovered unchanged in the fumes, while 85.6% of the diacetylmorphine from each tablet was recovered, either unchanged in the fumes or as non-volatilised residue. Recovery was found to be reproducible and only small differences were found between the tablet types. The experimental set-up was found to efficiently collect the vapours resulting from heating the powder. Under the tested experimental conditions, no evidence was found that degradation products of diacetylmorphine or caffeine, other than 6-acetylmorphine (5.9%) had volatilised, even though a decomposed residue was present after heating diacetylmorphine-caffeine samples. Diacetylmorphine-caffeine was found to be a suitable basis for pharmaceutical heroin to be used by 'chasing the dragon'.

Evidence of addiction by anesthesiologists as documented by hair analysis

Chemical dependency is a disease that can affect all professions. Among the health care professionals, anesthesiologists represent a specific group. Numerous factors have been proposed to explain the high incidence of drug abuse among anesthesiologists. These include: easy access to potent drugs, particularly narcotics, highly addictive potential of agents with which they are in contact, and easy diversion of these agents since only small doses will initially provide an effect desired by the abuser. Opioids are the drugs of choice for anesthesiologists, and among them fentanyl and sufentanil are the most commonly used. Alcohol is mostly abused by older anesthesiologists. Propofol, ketamine, thiopental and midazolam are also abused. In fact, all but quaternary ammonium drugs can be observed. Signs and symptoms of addiction in the hospital workplace include: unusual changes in behavior, desire to work alone, refusal of lunch relief or breaks, volunteer for extra cases, call, come in early and leave late, frequent restroom breaks, weight loss and pale skin, malpractice, behind on charts .... Toxicological investigations are difficult, as the drugs of interest are difficult to test for. In most cases, half-lives of the compounds are short, and the circulating concentrations weak. It is, therefore, necessary to develop tandem mass spectrometry procedures to satisfy the criteria of identification and quantitation. In most cases, blood and/or urine analyses are not useful to document impairment, as these specimens are collected at inadequate moments. Hair analysis appears, therefore, as the unique choice to evidence chronic exposure. Depending the length of the hair shaft, it is possible to establish an historical record, associated to the pattern of drug use, considering a growth rate of about 1cm/month. An original procedure was developed to test for fentanyl derivatives. After decontamination with methylene chloride, drugs are extracted from the hair by liquid/liquid extraction after incubation in pH 8.4 phosphate buffer. Fentanyl derivatives are analyzed by GC-MS/MS. The following cases are included in this paper: Case 1: 50-year-old anesthetist, positive for fentanyl (644 pg/mg); Case 2: 42-year-old anesthetist, positive for fentanyl (101 pg/mg) and sufentanil (2 pg/mg); Case 3: 40-year-old anesthetist, positive for codeine (210 pg/mg), alfentanil (30 pg/mg) and midazolam (160 pg/mg); Case 4: 46-year-old nurse, found dead, positive for alfentanil (2 pg/mg) and fentanyl (8 pg/mg). In these cases, the combination of an alternative specimen (hair) and hyphenated analytical techniques (tandem mass spectrometry) appears to be a pre-requisite.

Buprenorphine and Norbuprenorphine Concentrations in Human Breast Milk Samples Determined by Liquid Chromatography-Tandem Mass Spectrometry

Buprenorphine (BUP) is considered to be safe during pregnancy. However, the extent of BUP transfer into breast milk has not been investigated thoroughly. Because the drug concentration in the milk is 1 of the determinants in the assessment of the exposure risk, a rapid and sensitive LC-MS/MS method has been developed and evaluated to measure BUP and norbuprenorphine (norBUP) concentrations in milk. A solid-phase and 2 liquid-liquid extraction procedures have been compared. The lower limits of detection and quantification were 0.05 ng/mL and 0.18 ng/mL for BUP and 0.05 ng/mL and 0.20 ng/mL for norBUP, respectively, using a sample volume of 0.5 mL milk. BUP and norBUP concentrations determined from 10 random breast milk samples collected over 4 successive days from a lactating woman during buprenorphine maintenance therapy ranged from 1.0 to 14.7 and 0.6 to 6.3 ng/mL, respectively. Drug exposure of the infant may be considered to be low. Further investigations may seek to extend these preliminary findings to evaluate an infant's level of BUP exposure through breast milk.

[Shelf-lives of morphine and pethidine solutions stored in patient-controlled analgesia devices: physico-chemical and microbiological stability study]

Morphine and meperidine in Patient-Controlled Analgesic devices are commonly used to treat chronic pain patients. These devices deliver a programmed amount of drug and allow self-administration by the patient depending on the pain. In our department of pharmacy, 300 devices were manufactured in 2003. The aim of this study was to assess their shelf-life. The devices were filled aseptically and without preservatives with 1 and 40 mg/ml morphine solution and 5 and 20 mg/ml meperidine and stored over 30 days at room temperature and protected from light. Culture assay of the solutions showed that they remained sterile for 30 days. No turbidity of any solutions from samples collected twice a week was noticed. pH and osmolarity remained constant. Drug concentrations were determined using stability indicating HPLC method, as we showed that degradation products can be separated from the drugs. Little loss of meperidine occurred within 21 days (<5%) and morphine concentration, which increased, because of solvent evaporation, remained lower than 5% within 21 days but increased up to 10% after 30 days. No traces of degradation products (pseudomorphine or pethidic acid) were detected. The physicochemical and microbiological stability of morphine and meperidine hydrochlorides stored in such devices has been established for 21 days at room temperature and protected from light.

Lipid/peptide/nucleotide separation with MALDI-ion mobility-TOF MS

Matrix-assisted laser desorption/ionization when combined with ion mobility-orthogonal time-of-flight mass spectrometry is a viable technique for fast separation and analysis of biomolecules in complex mixtures. Isobaric lipid, peptide, and oligonucleotide ions are preseparated before mass analysis by differences of up to 30% in mobility drift time. Ions of similar chemical type fall along well-defined "trend lines" (with deviations of approximately 3%) when plotted in two-dimensional representations of ion mobility as a function of m/z. Discussion of fundamental and technical limitations of the technique point to its potential for being most useful when applied to systems such as bodily fluids and intact tissue, where an alternative chemical or chromatographic preseparation step prior to mass analysis is either impractical or undesirable.

IN VITRO AND IN VIVO EVALUATION OF THE METABOLISM AND PHARMACOKINETICS OF SEBACOYL DINALBUPHINE

A diester prodrug of nalbuphine, sebacoyl dinalbuphine (SDN), and its long-acting formulation are currently being developed to prolong the duration of nalbuphine. A comparative in vitro hydrolysis study was conducted for SDN in rat, rabbit, dog, and human blood. Both SDN and nalbuphine in blood or plasma were measured by high-performance liquid chromatography. The hydrolysis rates of SDN in blood were ranked as follows: rat > rabbit > human > dog. The rapid formation of nalbuphine in the blood accounted for almost 100% of the prodrug, which supported the contention that nalbuphine is the major metabolite after SDN hydrolysis. The hydrolysis profiles of SDN were similar both in plasma and in red blood cells when compared in the blood. In vitro release results of SDN long-acting formulation showed that the rate-limited step of SDN hydrolysis to nalbuphine in blood is the penetration of SDN from oil into the blood. After intravenous administration of SDN in sesame oil into rats, nalbuphine quickly appeared in plasma and, thereafter, exhibited monoexponential decay. Pharmaceutical dosage forms affecting the drug disposition kinetics were demonstrated after intravenous administration. The AUC of nalbuphine was significantly higher and clearance was significantly lower, without changes in the t(1/2) of nalbuphine after intravenous dosing of SDN in sesame oil when compared with that of intravenous dosing with nalbuphine HCl in rats. Overall, these results suggest that SDN fulfilled the original pro-soft drug design in which the prodrug can rapidly metabolize to nalbuphine, and no other unexpected compounds were apparent in the blood.

Quality assessment for tramadol in pharmaceutical preparations with thin layer chromatography and densitometry

Research studies have been carried out to develop a chromatographic and densitometric method suitable for identification and determination of tramadol and impurities. In addition, the stability of tramadol in solutions was investigated, including an effect of solution pH, temperature and incubation time. In the first instance the conditions for identification and quantitative determination of tramadol and impurities in pharmaceutical preparations were established. The separation was performed on silica gel-coated chromatographic plates (HPTLC) using two mobile phases: (I) chloroform-methanol-glacial acetic acid (9:2:0.1, v/v/v); (II) chloroform-toluene-ethanol (9:8:1, v/v/v). The UV densitometry was carried out at lambda = 270 nm. The developed method is of high sensitivity and low detection and determination limits ranging from 0.044 to 0.35 microg. For individual constituents the recovery ranges from 93.23 to 99.66%. The next step was to evaluate the stability of tramadol and determine a method of decomposition under various experimental conditions. It was found that tramadol decomposes in various ways in acidic and basic environments producing (1RS)-[2-(3-methoxyphenyl)cyclohex-2-enyl]-N,N-dimethylmethanamine (imp. B) and (1RS, 2RS)-2-[(dimethylamino)methyl]-1-(3-methoxyphenyl)cyclohexanol (imp. cis-T) or imp. cis-T, respectively.

Postmortem Morphine Concentrations Following Use of a Continuous Infusion Pump

We report a case involving unusually high postmortem morphine concentrations in a 44-year-old male with end-stage pancreatic cancer. He was receiving morphine for pain control via a single subclavian intravenous catheter. Allegations of foul play were made by family members at the time of death, so a full autopsy was performed. Comprehensive toxicology on autopsy samples indicated that morphine was the only drug present. Quantitative analysis of free and total morphine revealed extraordinarily high concentrations of the drug. Free morphine concentrations in heart blood, vitreous fluid, brain, liver, stomach contents, and urine were 96 mg/L, 52 mg/L, 26 mg/kg, 88 mg/kg, 82 mg/L, and 976 mg/L, respectively. Total morphine concentrations in heart blood, vitreous fluid, brain, liver, and stomach contents were 421 mg/L, 238 mg/L, 65 mg/kg, 256 mg/kg, and 325 mg/L, respectively. Records indicate that the infusion pump may have continued to deliver the drug for 15-45 min following death. Despite compelling toxicological data, the cause of death was determined to be complication of adenocarcinoma of the pancreas, and the manner was natural. This report highlights issues surrounding postmortem toxicological interpretation within the context of chronic pain management.

The Insulin Pump as Murder Weapon

Microprocessor-controlled insulin pumps designed for continuous delivery of short-acting insulin analogs into subcutaneous tissues offer several important potential benefits for diabetic patients. The delivery of other substances using these systems is technically feasible. We present a case of homicide involving lethal doses of etomidate and atracurium injected via the victim's insulin pump. This unique situation could be encountered by homicide investigators more frequently as the popularity of these systems continues to grow.

A forensic toxicological dilemma: the interpretation of post-mortem concentrations of central acting analgesics

Dora V., a 88-year-old pensioner suffering from a hiatus hernia, died at the home of an orthopaedist and his wife, an anaesthetist, immediately after she had received a dose of 300 mg pethidine via intravenous infusion in a timeframe of about 90 min. One day before her death a befriended notary of the couple visited Dora V. and obtained a blank signature. After her death, a will was forged using this signature, rendering the couple sole heirs of Dora V.'s estate with a value of several million euros. Post-mortem toxicology was performed in three different institutes of legal medicine. The concentrations of pethidine in peripheral venous blood were between 6.1 and 6.5mg/l and 9.5 and 17.2mg/kg in brain. Pharmacokinetic calculation confirms the given dose. There was no doubt that the cause of death was acute pethidine intoxication. The accused couple claimed that this dose of pethidine was indicated to relief pain, and as the pathologists said in their expert opinions that the hiatus hernia could explain her death, the court had to acquit the accused. This very special case demonstrates that preconceived murder of a sick person with suitable analgesics cannot be proven--at least not with the methods available to forensic toxicology and pathology. This has to be taken into consideration if euthanasia will be legalised under special circumstances.

Postmortem toxicology of drugs of abuse

Conducting toxicology on post-mortem specimens provides a number of very significant challenges to the scientist. The range of additional specimens include tissues such as decomposing blood and other tissues, hair, muscle, fat, lung, and even larvae feeding on the host require special techniques to isolate a foreign substance and allow detection without interference from the matrix. A number of drugs of abuse are unstable in the post-mortem environment that requires careful consideration when trying to interpret their significance. Heroin, morphine glucuronides, cocaine and the benzodiazepines are particularly prone to degradation. Moreover, redistributive process can significantly alter the concentration of drugs, particularly those with a higher tissue concentration than the surrounding blood. The designer amphetamines, methadone and other potent opioids will increase their concentration in blood post-mortem. These processes together with the development of tolerance means that no concentration of a drug of abuse can be interpreted in isolation without a thorough examination of the relevant circumstances and after the conduct of a post-mortem to eliminate or corroborate relevant factors that could impact on the drug concentration and the possible effect of a substance on the body. This article reviews particular toxicological issues associated with the more common drugs of abuse such as the amphetamines, cannabinoids, cocaine, opioids and the benzodiazepines.

Performance characteristics of the Cozart RapiScan Oral Fluid Drug Testing System for opiates in comparison to ELISA and GC/MS following controlled codeine administration

Oral fluid is an interesting alternative matrix for drug testing in many environments, including law enforcement, workplace drug testing, and drug treatment facilities. Performance characteristics of the FDA-cleared, qualitative, Cozart RapiScan Opiate Oral Fluid Drug Testing System (Opiate Cozart RapiScan System or Opiate CRS) were compared to the semi-quantitative Cozart Microplate EIA Opiate Oral Fluid Kit (Opiate ELISA) and to gas chromatography/mass spectrometry (GC/MS). The following oral fluid opiate cutoffs were evaluated: the GC/MS limit of quantification (LOQ) of 2.5 mg/l; 15 microg/l currently used for oral fluid testing in the United Kingdom (UK); 30 microg/l (Opiate CRS cutoff); and 40 microg/l, the proposed Substance Abuse and Mental Health Services Administration (SAMHSA) cutoff. Subjects provided informed consent to participate in this IRB-approved research and resided on the closed research ward throughout the study. Three oral codeine doses of 60 mg/70 kg were administered over a 7-day period. After a 3-week break, subjects received three doses of 120 mg/70 kg within 7 days. Oral fluid specimens (N = 1273) were analyzed for codeine (COD), norcodeine (NCOD), morphine (MOR) and normorphine (NMOR) by GC/MS with an LOQ of 2.5 microg/l for all analytes. MOR and NMOR were not detected in any sample; 26.5% of the specimens were positive for COD and 13.7% for NCOD. Opiate CRS uses a preset, qualitative cutoff of 10 microg/l; this is equivalent to 30 microg/l in undiluted oral fluid as the oral fluid collection process involves a 1:3 dilution with buffer. Sensitivity, specificity, and efficiency of Opiate CRS compared to Opiate ELISA were 98.6, 98.1, and 98.2% at a 30 microg/l cutoff and 99.0, 96.2, and 96.6% at a 40 microg/l cutoff. Compared to the much lower GC/MS LOQ of 2.5 microg/l, sensitivity, specificity and efficiency were 66.8, 99.3 and 90.7%. Increasing the GC/MS cutoff to the current UK level yielded performance characteristics of 81.5% (sensitivity), 99.3% (specificity), and 95.4% (efficiency). Using a GC/MS cutoff identical to the preset Opiate CRS cutoff yielded sensitivity, specificity, and efficiency of 88.5, 99.2, and 97.5%, respectively. At the proposed SAMSHA confirmation cutoff of 40 microg/l, sensitivity increased with little change in specificity and efficiency (91.3% sensitivity, 98.9% specificity, and 97.5% efficiency). Oral fluid is a suitable matrix for detecting drugs of abuse. Opiate CRS, with a 30 microg/l cutoff, is sufficiently sensitive, specific and efficient for oral fluid opiate analysis, performing similarly to Opiate ELISA at the same cutoff, and having performance characteristics >91% when compared to GC/MS at the proposed SAMHSA cutoff.

[An expert study of acute poisoning by phencyclidine derivatives]

Described are the results of a complex study of different objects and beverages for the content of synthetic drugs in them, i.e. phencyclidine and tenocyclidine, by using the methods of planar and gas chromatography, UV-spectrometry and mass spectrometry/gas chromatography.

Determination of MPTP, a toxic impurity of pethidine

Pethidine, predominantly a mu-receptor agonist, is a phenyl-piperidinic synthetic drug. It is used in the management of moderate to several pain. A possible hydrolytic degradation of an ester group can generate a very toxic compound, the N-methyl-4-phenyl-1,2,3,6 tetrahydropyridine (MPTP) which contaminates the drug. Because of the toxicity of MPTP a suitable method for its determination must be selective and sensitive. Afterwards we propose simple methods to determine pethidine and MPTP by capillary electrophoresis (CE), MECK and RP-high performance liquid chromatography (HPLC) looking at the limit of detection obtained using these three techniques. CE was carried out using as running buffer ammonium acetate (pH 8.3). MECK was performed with a borate buffer (pH 8.3) containing sodium dodecylsulphate and trimethyl-beta-cyclodextrins. RP-HPLC was carried out on a RP18 stationary phase, using as mobile phase a mixture of phosphate buffer (pH 7) containing acetonitrile and 1% of diethylamine.

Determination of tramadol in hair using solid phase extraction and GC-MS

Tramadol is a centrally acting synthetic analgesic with mu-opioid receptor agonist activity, it is a widely prescribed analgesic used in the treatment of moderate to severe pain and as an alternative to opiates. Tramadol causes less respiratory depression than morphine at recommended doses. Its efficacy and low incidence of side effects lead to its unnecessary prescribing in patients with mild pain. Tramadol was classified as a "controlled drug" long after its approval for use in Jordan. Analysis of drugs of abuse in hair has been used in routine forensic toxicology as an alternative to blood in studying addiction history of drug abusers. A method for the determination of tramadol in hair using solid phase extraction and gas chromatography-mass spectrometry (GC-MS) is presented, the method offers excellent precision (3.5-9.8%, (M)=6.77%), accuracy (6.9-12%, M=9.4%) and limit of detection 0.5 ng/mg. The recovery was in the range of 87-94.3% with an average of 90.75%. The calibration curve was linear over the concentration range 0.5-5.0 ng/mg hair with correlation coefficient of 0.998. The developed method was tested on 11 hair samples taken from patients using tramadol as prescribed by their physician along with other different drugs in treating chronic illnesses. Tramadol was detected in all hair samples at a concentration of 0.176-16.3 ng/mg with mean concentration of 4.41 ng/mg. The developed method has the potential of being applied in forensic drug hair testing. In Jordan, hair drug testing started to draw the attention of legal authorities which stimulated forensic toxicologists in recent years to develop methods of analysis of drugs known or have the potential to be abused.

A fatal drug interaction between oxycodone and clonazepam

A case is presented of a fatal drug interaction caused by ingestion of oxycodone (Oxycontin) and clonazepam (Klonapin). Oxycodone is an opium alkaloid used in long-term pain management therapy. Clonazepam is a benzodiazepine used for the treatment of seizures and panic disorders. The Drug Abuse Warning Network (DAWN) has reported an increase of 108% in the last two years of emergency department episodes related to Oxycontin. Six billion prescriptions were written for Oxycontin in the year 2000, an 18-fold increase from four years previous (1). Oxycontin has recently gained enormous notoriety at the local and national levels; however, there are very few previously documented cases of lethal drug interactions between oxycodone and clonazepam. Synergistic effects between these two drugs are postulated to arise from different agonistic mechanisms producing similar physiological changes. It is also theorized that clonazepam may inhibit the metabolism of oxycodone. A 38-year-old white female was found dead in Jefferson County, Tennessee in March of 2001. The deceased had physical evidence of previous drug abuse and positive serological findings of hepatitis B and C. Prescription pill bottles filled under the name of the deceased, as well as another name, were found with the body. Serum, urine and gastric contents from the deceased were screened for numerous drugs and metabolites using a combination of thin layer chromatography and immunoassay techniques (EMIT and FPIA). Analysis of biological specimens from the deceased revealed the presence of: benzodiazepines, opiates (oxycodone), and trazodone metabolites in the serum; cannabinoids, benzodiazepines, opiates (oxycodone), trazodone, trazodone metabolites, nicotine, and nicotine metabolite in the urine; and benzodiazepines, opiates (oxycodone), nicotine, and nicotine metabolite in the gastric contents. Quantitative analyses for clonazepam was performed by high performance liquid chromatography (HPLC) and revealed a plasma concentration of 1.41 microg/mL. Plasma oxycodone and urine 11-nor-carboxy-delta-9-tetrahydrocannabinol concentrations were determined by gas chromatography/mass spectrometry and revealed concentrations of 0.60 microg/mL and 27.9 ng/mL, respectively. The deceased had pathologies consistent with severe central nervous system (CNS) and respiratory depression produced by high concentrations of clonazepam and oxycodone including collapsed lungs, aspirated mucus, and heart failure. The pathologies were sufficient to cause death, which was officially attributed to a drug overdose; however, the manner of death was unknown.