Are point-of-care urine drug testing devices suitable for antenatal drug screening? A study verifying the Alere® Drug Screen Test Cup for the detection of six classes of drug in a pregnant population.

BACKGROUND: Currently, there are no national guidelines for antenatal drug testing. At Colchester Hospital, we use a strategy of screen-only using point-of-care testing to detect illicit drug use in pregnancy. To determine the suitability of this approach, we have compared the results of urine analysis by point-of-care testing with another NHS specialist clinical toxicology service that uses confirmation mass spectrometry. METHODS: A total of 482 anonymized random urine specimens from antenatal clinics were tested for six drug classes: amphetamine, benzodiazepines, buprenorphine, cocaine, methadone and opiates using the Alere™ Drug Screen Urine Test Cup. The manufacturer's claims for positive cut-off and result stability were verified using spiked blank urine. Confirmatory testing was performed using ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) for detection of 26 individual drugs. RESULTS: Of 473 urine samples with adequate volume for point-of-care screening, 4.4% tested positive: 19 opiate and 2 cocaine. Concordance between point-of-care screening and UPLC-MS/MS confirmation was 97.9% for all drugs and 78.9% for opiates. Using spiked urine, only positive results for opiates were stable when read up to the manufacturer's recommended time of 60 min. CONCLUSIONS: The key advantages of using point-of-care devices to detect drug use in pregnancy are that is convenient and cheap. However, the clinical utility of point-of-care testing is limited by its poor sensitivity. Best practice is to confirm results using a more specific and sensitive method. As a result of this study, we are now reviewing our own procedures to consider introducing routine confirmation by mass spectrometry.

Analytical evidence to show letters impregnated with novel psychoactive substances are a means of getting drugs to inmates within the UK prison service.

Introduction Novel psychotropic substances also known as legal highs are a major concern in UK prisons, fuelling violence and putting a strain on resources for inmates requiring medical treatment for adverse effects. We provide a clinical toxicology service including routine screening for novel psychoactive substances. In 2015, we were approached by Her Majesty Prison Service search dog training team to advise on which novel psychoactive substances to target, and again in 2016 to further provide analytical support to test five letters which the dogs positively identified for novel psychotropic substances during routine searches of prison mail rooms. Here we provide the first analytical confirmation that letters sent to inmates are being used to smuggle novel psychotropic substances into UK prisons. Results Novel psychotropic substances were detected on all five letters and these included the stimulants ethylphenidate, methiopropamine and methoxiphenidaine, the sedative etizolam and the third generation synthetic cannabinoids 5F-AKB-48, AB-FUBINACA, MDMB-CHMICA. Other compounds detected include the class A drug cocaine, class B drug methylphenidate and the cutting agents lignocaine, benzocaine and procaine. Conclusion Novel psychotropic substances smuggled into UK prisons is a major safety and security concern. By analytically confirming letters sent to inmates do contain novel psychotropic substances, we have produced categorical evidence to support anecdotal suggestions that novel psychotropic substances are entering UK prisons in this manner.

Analysis of legal high materials by ultra-performance liquid chromatography with time of flight mass spectrometry as part of a toxicology vigilance system: what are the most popular novel psychoactive substances in the UK?

Introduction Legal highs also known as novel psychoactive substances mimic the effects of classic drugs of abuse. Challenges to developing screening services for novel psychoactive substances include identifying which novel psychoactive substances are available to target. Using new techniques such as exact mass time of flight can help identify common novel psychoactive substances to target for screening patient samples by routine methods such as tandem mass spectrometry. We demonstrate this strategy working in our own clinical toxicology laboratory after qualitative analysis of 98 suspect materials for novel psychoactive substances by ultra-performance liquid chromatography with time of flight mass spectrometry. Results From July 2014 to July 2015 we received 98 requests to test a range of different suspect materials for novel psychoactive substances including herbs, tobacco, liquids, pills and powders. Overall, 87% of the suspect materials tested positive for novel psychoactive substances, and 15% for controlled drugs. Three common novel psychoactive substances were present in 74% of the suspect materials: methiopropamine, a methamphetamine analogue; ethylphenidate, a cocaine mimic; and the third generation synthetic cannabinoid 5F-AKB-48. For the 55 branded products we tested only 24% of the stated contents matched exactly the compounds we detected. Conclusion Testing suspect materials using ultra-performance liquid chromatography with time of flight mass spectrometry has identified three common novel psychoactive substances in use in the UK, simplifying the development of a relevant novel psychoactive substances screening service to our population. By incorporating this into our routine liquid chromatography tandem mass spectrometry drugs of abuse screen, then offers a clinically relevant novel psychoactive substances service to our users. This strategy ensures our clinical toxicology service continues to remain effective to meet the challenges of the changing drug use in the UK.

1-Adamantylamine a simple urine marker for screening for third generation adamantyl-type synthetic cannabinoids by ultra-performance liquid chromatography tandem mass spectrometry.

Background Synthetic cannabinoids (NOIDS) are novel psychotropic drugs (NPS) currently freely sold in the United Kingdom as 'research chemicals'. Detection of NOIDS use is not available in current routine methods. Here we describe a marker which helps determine which patients have used these substances. Methods In a test case, ultra-performance liquid chromatography mass spectrometry (UPLC-Tof) was used to screen the legal high Herbal Haze II, the contents of hand-rolled cigarettes and five patient samples for NOIDS and their metabolites. Results Analysis of legal high Herbal Haze II and cigarettes identified the third generation adamantyl-type NOIDS N-(1-adamantyl)-1-pentyl-1H-indazole-3-carboxamide (AKB-48), 5F-AKB-48 and N-adamantyl-1-fluoropentylindole-3-carboxamide (STS-135). Out of 18 potential metabolites, 1-adamantylamine (C10H17N) was detected in all five urine samples. This adamantyl-type NOID marker was incorporated into our routine LC-MS/MS urine screen. Out of 14,436 random urine samples screened over eight months, 296 (2.05%) tested positive for the adamantyl-type NOID marker. Conclusion We have discovered a urine marker for identifying patients smoking legal high products containing the third generation adamantyl-type NOIDS such as AKB-48 and its fluoropentyl analogue 5F-AKB-48, which are among the most popular NOIDS currently available in legal high products sold in UK. This marker can be incorporated into routine LC-MS/MS drug screening alongside classic drugs of abuse. Positive detection rates for this new legal high marker are greater than for established classic drugs that are routinely screened such as amphetamine. This work highlights the need for a flexible toxicology screening service capable of adapting to changes in drug use such as the growing popularity of legal highs/NPS.

Five-year review of a UK 24 hour testing service for plasma ethylene glycol and diethylene glycol.

BACKGROUND: We present a 5-year review of our UK service for plasma ethylene glycol and diethylene glycol determination in cases of acute poisoning. METHODS: Ethylene glycol and diethylene glycol have been measured on all samples received for screening for toxicity by gas chromatography-flame ionization detection over a five-year period. A detailed audit of the results has been undertaken. RESULTS: In this period, we received 811 requests, 56% were for first-time screening and 44% repeat analysis where a positive sample has already been received. Of the first-time screen samples, 33.5% screened positive for glycol poisoning. The mean positive ethylene glycol concentration was 1204 mg/L (range 31 to 8666 mg/L). Diethylene glycol was present in 14% of ethylene glycol positive samples but never found alone. CONCLUSIONS: The data presented here suggest it is not essential to measure diethylene glycol since its inclusion is rarely likely to change patient management.

Ethnic variation of thiopurine S-methyltransferase activity: a large, prospective population study.

UNLABELLED: The use of azathioprine (and its metabolite mercaptopurine) is limited by toxicity, especially myelosuppression, which is related to activity of the enzyme thiopurine S-methyltransferase (TPMT). TPMT activity varies between individuals and is considered deficient in one in 300 cases. AIMS & METHODS: We identified TPMT activity within an ethnically diverse population of patients attending an inner-city hospital phlebotomy service. A total of 1000 subjects were recruited and analyzed with respect to age, sex and ethnicity. RESULTS: Samples were analyzed from 456 Caucasians, 342 South Asians and 180 Afro-Caribbeans. Six subjects had deficient TPMT activity (0.6%: four women, two men; four Caucasians, one Afro-Caribbean, one South Asian). TPMT activity (nmol 6-methylthioguanine (6-MTG)/gHb/h) ranged 0-76 (median [interquartile range]: 33 [28-39]). Enzyme activity was lower in Afro-Caribbeans (30 [25-37.5]) than Caucasians (34 [29-40]) and South Asians (33 [29-38]), which was significant after adjustment for age and sex (p < 0.0001). Activity was lower in women (p = 0.022), especially South Asian females (n = 194; 32 [28-36]), compared with (35 [30-40]) in men (n = 148; p = 0.002). CONCLUSIONS: A higher prevalence of TPMT deficiency was recorded than in previous studies. Afro-Caribbeans have lower activity than Caucasians and South Asians. TPMT enzyme activity was lower among females, especially in South Asians.

Reference intervals for thiopurine S-methyltransferase activity in red blood cells using 6-thioguanine as substrate and rapid non-extraction liquid chromatography.

BACKGROUND: Although widely used, thiopurine drugs have a narrow therapeutic index and treatment can result in life-threatening toxicity, the basis being pharmacogenetic variation in thiopurine metabolism by thiopurine S-methyltransferase (TPMT). We recently developed a modified phenotyping assay to determine TPMT activity in red blood cells. Here we describe improvements to the method and establish reference intervals in a large prospective study. METHODS: A modified enzyme assay for TPMT activity is reported. It uses 6-thioguanine as substrate with heat treatment of the incubate to stop the reaction and precipitate protein prior to high-performance liquid chromatographic (HPLC) analysis. Measurement of the reaction product, 6-methylthioguanine (6-MTG), uses HPLC with fluorimetric detection. RESULTS: The assay shows excellent characteristics, with clear discrimination of patients who are deficient in TPMT activity (< 5 nmol 6-MTG per g Hb per h) from heterozygotes (5-24 nmol 6-MTG per g Hb per h) and patients with normal activity (>25 nmol 6-MTG per g Hb per h). CONCLUSION: A modified TPMT assay is described which is suited for routine analysis in a regional centre. The method overcomes the need for extraction and has speeded up the chromatographic determination of 6-MTG, enabling large numbers of samples to be analysed. A prospective study of 1000 individuals has established the distribution of TPMT activity using the assay.