Determination of Opioid Analgesics in Hair Samples Using Liquid Chromatography/Tandem Mass Spectrometry and Application to Patients Under Palliative Care

Pharmacological Treatments and Therapeutic Drug Monitoring in Patients with Chronic Pain

Pain is an unpleasant sensory and emotional experience that affects every aspect of a patient's life and which may be treated through different pharmacological and non-pharmacological approaches. Analgesics are the drugs most commonly used to treat pain, and in specific situations, the use of opioids may be considered with caution. These drugs, in fact, do not always induce optimal analgesia in patients, and several problems are associated with their use. The purpose of this narrative review is to describe the pharmacological approaches currently used for the management of chronic pain. We review several aspects, from the pain-scale-based methods currently available to assess the type and intensity of pain, to the most frequently administered drugs (non-narcotic analgesics and narcotic analgesics), whose pharmacological characteristics are briefly reported. Overall, we attempt to provide an overview of different pharmacological treatments while also illustrating the relevant guidelines and indications. We then report the strategies that may be used to reduce problems related to opioid use. Specifically, we focus our attention on therapeutic drug monitoring (TDM), a tool that could help clinicians select the most suitable drug and dose to be used for each patient. The actual potential of using TDM to optimize and personalize opioid-based pain treatments is finally discussed based on recent scientific reports.

Personalized Medicine in Cancer Pain Management

BACKGROUND

Previous studies have documented pain as an important concern for quality of life (QoL) and one of the most challenging manifestations for cancer patients. Thus, cancer pain management (CPM) plays a key role in treating pain related to cancer. The aim of this systematic review was to investigate CPM, with an emphasis on personalized medicine, and introduce new pharmacogenomics-based procedures for detecting and treating cancer pain patients.

METHODS

This study systematically reviewed PubMed from 1990 to 2023 using keywords such as cancer, pain, and personalized medicine. A total of 597 publications were found, and after multiple filtering processes, 75 papers were included. In silico analyses were performed using the GeneCards, STRING-MODEL, miRTargetLink2, and PharmGKB databases.

RESULTS

The results reveal that recent reports have mainly focused on personalized medicine strategies for CPM, and pharmacogenomics-based data are rapidly being introduced. The literature review of the 75 highly relevant publications, combined with the bioinformatics results, identified a list of 57 evidence-based genes as the primary gene list for further personalized medicine approaches. The most frequently mentioned genes were CYP2D6, COMT, and OPRM1. Moreover, among the 127 variants identified through both the literature review and data mining in the PharmGKB database, 21 variants remain as potential candidates for whole-exome sequencing (WES) analysis. Interestingly, hsa-miR-34a-5p and hsa-miR-146a-5p were suggested as putative circulating biomarkers for cancer pain prognosis and diagnosis.

CONCLUSIONS

In conclusion, this study highlights personalized medicine as the most promising strategy in CPM, utilizing pharmacogenomics-based approaches to alleviate cancer pain.

Microextraction by Packed Sorbent as a Novel Strategy for Sample Clean-Up in the Determination of Methadone and EDDP in Hair

A microextraction by packed sorbent (MEPS) procedure for rapid concentration of methadone and its primary metabolite (EDDP) in hair samples was developed. The miniaturized approach coupled to gas chromatography with tandem mass spectrometry (GC-MS-MS) was successfully validated. Hair samples (50 mg) were incubated with 1 mL of 1 M sodium hydroxide for 45 min at 50°C, time after which the extract was neutralized by adding 100 μL of 20% formic acid. Subsequently, MEPS was applied using a M1 sorbent (4 mg; 80% C8 and 20% strong cation-exchange (SCX)), first conditioned with three 250-μL cycles of methanol and three 250-μL cycles of 2% formic acid. The extract load occurred with nine 150-μL cycles followed by a washing step involving three 50-μL cycles with 3.36% formic acid. For the elution of the analytes, six 100-μL cycles of 2.36% ammonium hydroxide in methanol were applied. The method was linear from 0.01 to 5 ng/mg, for both compounds, presenting determination coefficients greater than 0.99. Precision and accuracy were in accordance with the statements of international guidelines for method validation. This new miniaturized approach allowed obtaining recoveries ranging from 73 to 109% for methadone and 84 to 110% for EDDP, proving to be an excellent alternative to classic approaches, as well as other miniaturized procedures.

Determination of morphine and its metabolites in the biological samples: an updated review

Morphine (MO) as an opioid analgesic is used for the treatment of moderate-to-severe pains, particularly cancer-related pains. Pharmacologic studies on MO are complicated due to drugs binding to the protein or metabolization to active metabolites, and even inter-individual variability. This necessitates the selection of a reliable analytical method for monitoring MO and the concentrations of its metabolites in the biological samples for the pharmacokinetic or pharmacodynamic investigations. Therefore, this study was conducted to review all the analytical research carried out on MO and its metabolites in the biological samples during 2007-2019 as an update to the study by Bosch et al. (2007).

A Retrospective Analysis of Selected Opioids in Hair of Workplace Drug Testing Subjects

Opioids, both naturally occurring and semisynthetic, are effective pain management medications, but also possess the potential for abuse. Analyses of over 37,000 head and body hair samples containing codeine, morphine, hydrocodone, hydromorphone, oxycodone or oxymorphone provide a view of use habits of workplace-testing subjects that cannot be obtained from fluid matrices results. Testing was performed using FDA cleared immunoassays using either 2 ng morphine or oxycodone per 10 mg hair as calibrators. Non-negative screening samples were washed with an extended aqueous wash procedure followed by LC-MS-MS confirmation at a cutoff concentration of 2 ng opioid per 10 mg hair. The LC-MS-MS method measured codeine, morphine, 6-acetylmorphine, hydrocodone, hydromorphone, oxycodone and oxymorphone with an administratively established LOQ of 0.50 ng opioid per 10 mg hair. The linear range was 0.50-100 ng morphine per 10 mg hair, and 0.50-150 ng opioid per 10 mg hair for all other measured analytes. For all analytes, within run precision was ≤5.4%, and between-run precision was ≤6.4%. Analysis of samples containing metabolites found that, among codeine positive samples, 97% contained less than 10% morphine metabolite and 88% less than 20% hydrocodone metabolite, among hydrocodone positive samples, 97% contained less than 10% hydromorphone metabolite and 95% of oxycodone positive samples contained less than 10% oxymorphone metabolite. Our analysis of opioid-positive samples may provide guidelines for interpretation of hair opioid levels typically observed in workplace testing.

Determination of Selected Opiates in Hair Samples Using Microextraction by Packed Sorbent: A New Approach for Sample Clean-up

In this article the development and validation of an analytical method using microextraction by packed sorbent (MEPS) to determine tramadol (TRM), codeine (COD), morphine (MOR), 6-acetylcodeine (6-AC), 6-monoacetylmorphine (6-MAM) and fentanyl (FNT) in hair samples by gas chromatography coupled to tandem mass spectrometry (GC–MS-MS) is presented. The MEPS used a mixed mode sorbent, and the steps for sample cleanup were conditioning (three cycles of 250 μL of methanol and three cycles of 250 μL formic acid 2%); sample load (15 cycles of 150 μL); wash (150 μL of 3.36% formic acid); and elution (eight cycles of 100 μL of ammonium hydroxide 2.36% (in methanol)). Linearity was obtained from the lower limit of quantitation (LLOQ) up to 5 ng/mg, with all target compounds revealing determination coefficients >0.99. The LLOQs achieved were 0.01 ng/mg for TRM, COD and 6-AC, and 0.025 ng/mg for MOR, 6-MAM and FNT. The recoveries ranged from 74 to 90% (TRM), 51 to 59% (COD), 22 to 36% (MOR), 69 to 99% (6-AC), 53 to 61% (6-MAM) and 75 to 86% (FNT). Precision and accuracy revealed coefficients of variation typically below 15% and relative errors within a ±15% interval, respectively. This new approach has proven to be an excellent alternative to classic procedures, reducing the volumes of organic solvents required.

Development of a column-switching LC-MS/MS method of tramadol and its metabolites in hair and application to a pharmacogenetic study

Hair is a valuable specimen for monitoring long-term drug use. Tramadol is an effective opioid analgesic but is associated with risks such as drug dependence and unexpected toxicity arising from genetic differences in metabolism. However, few studies have been performed on the distribution of tramadol and its metabolites in hair. In the present study, a column-switching LC-MS/MS method was developed and fully validated for the simultaneous determination of tramadol and its phase I and II metabolites in hair. Furthermore, the distribution of tramadol and its metabolites in hair was investigated in a pharmacogenetic study. Tramadol and its metabolites were extracted from hair using methanol and injected onto LC-MS/MS. The validation results of selectivity, matrix effect, linearity, precision and accuracy were satisfactory. The (mean) concentrations of O-desmethyltramadol (ODMT) and N,O-didesmethyltramadol (NODMT) in the CYP2D6*10/*10 and CYP2D6*5/*5 groups were lower than those in the CYP2D6*wt/*wt group, while the (mean) concentrations of N-desmethyltramadol (NDMT) were higher. Moreover, the ratios of ODMT/tramadol, NDMT/tramadol and NODMT/NDMT were well correlated with the CYP2D6 genotypes. The developed method was successfully applied to the clinical study, which demonstrated that the concentrations of a drug and its metabolites in hair were dependent on the polymorphism of its metabolizing enzyme.

High Rates of Tramadol Use among Treatment-Seeking Adolescents in Malmö, Sweden: A Study of Hair Analysis of Nonmedical Prescription Opioid Use

Background

Nonmedical prescription opioid use (NMPOU) is a growing problem and tramadol has been suggested as an emerging problem in young treatment-seeking individuals. The aim of the present study was to investigate, through hair analysis, NMPOU in this group and, specifically, tramadol use.

Methods

In a study including 73 treatment-seeking adolescents and young adults at an outpatient facility for young substance users, hair specimens could be obtained from 59 subjects. Data were extracted on sociodemographic background variables and psychiatric diagnoses through MINI interviews.

Results

In hair analysis, tramadol was by far the most prevalent opioid detected. Thirty-two percent screened positive for opioids, and of those, all but one were positive for tramadol. Ninety-eight percent reported problematic cannabis use. Significantly more opioid-positive patients also screened positive for other (noncannabis) drugs, compared to nonopioid users. Sixty-four percent fulfilled criteria of DSM-IV psychiatric disorders, other than substance use disorders according to MINI. Fifty-three percent met the symptom criteria count of ADHD above cut-off level.

Conclusion

In the present setting, tramadol, along with high rates of cannabis use, may represent a novel pattern of substance use among young treatment-seeking subjects with problematic substance use and high rates of concurrent psychiatric problems.

Quantification of piritramide in human colostrum

WHAT IS KNOWN AND OBJECTIVE

In our university hospital (UZBrussel), one of the options to control post-operative pain after a Caesarean section under general anaesthesia is to administer piritramide by patient-controlled intravenous analgesia (PCIA). As no information is available about the possible transfer of this synthetic narcotic analgesic into breastmilk, women are frequently advised not to breastfeed their newborn. A sensitive liquid chromatographic (LC) method coupled with UV detection will therefore be developed and validated for the quantification of piritramide in colostrum samples to evaluate the presence of the analgesic in the first milk.

METHODS

The method included the isolation and concentration of piritramide from colostrum using protein precipitation and solid-phase extraction (SPE) using a mixed-mode cation exchange sorbent. Subsequently, the extracted samples were analysed on a microbore C₁₈ column (1 mm id) and a mobile phase consisting of 15 mm ammonium hydroxide in methanol/tetrahydrofuran/water 50 : 10 : 40 V/V/V.

RESULTS AND DISCUSSION

As colostrum contains a high amount of proteins, mixed-mode cation exchange SPE was preceded by a 1 : 2 dilution and protein precipitation with phosphoric acid followed by double centrifugation of the samples. The reversed-phase LC-UV method used a mobile phase at alkaline pH to obtain a selective method for piritramide and the internal standard pipamperone. After investigating the validation characteristics (linearity, accuracy, precision and stability), samples from ten patients who had received piritramide via PCIA during the first 48 h post-partum were analysed.

WHAT IS NEW AND CONCLUSION

To the best of our knowledge, this is the first method described for the quantification of the synthetic narcotic analgesic piritramide in colostrum samples. The obtained results suggest that after the administration of this opioid by PCIA to nursing mothers low concentrations of piritramide can be found in the first milk, but are mostly below the limit of quantification of 30 ng/mL.

Monitoring of adherence to headache treatments by means of hair analysis

Purpose

The aim of this study was to evaluate the potential of hair analysis to monitor medication adherence in headache patients undergoing chronic therapy. For this purpose, the following parameters were analyzed: the detection rate of 23 therapeutic drugs in headache patients’ hair, the degree of agreement between the self-reported drug and the drug found in hair, and whether the levels found in hair reflected the drug intake reported by the patients.

Methods

The study included 93 patients suffering from primary headaches declaring their daily intake of at least one of the following drugs during the 3 months before the hair sampling: alprazolam, amitriptyline, citalopram, clomipramine, clonazepam, delorazepam, diazepam, duloxetine, fluoxetine, flurazepam, levomepromazine, levosulpiride, lorazepam, lormetazepam, mirtazapine, paroxetine, quetiapine, sertraline, topiramate, trazodone, triazolam, venlafaxine, and zolpidem.

A detailed pharmacological history and a sample of hair were collected for each patient. Hair samples were analyzed by liquid chromatography-electrospray tandem mass spectrometry, using a previously developed method.

Results

All 23 drugs were detected in the examined hair samples. The agreement between the self-reported drug and the drug found in hair was excellent for most analytes (P < 0.001, Cohen’s kappa); a statistically significant relationship (P < 0.05, linear regression analysis) between dose and hair level was found for amitriptyline, citalopram, delorazepam, duloxetine, lorazepam, and venlafaxine.

Conclusions

Hair analysis proved to be a unique matrix to document chronic drug use in headache patients, and the level found for each individual drug can represent a reliable marker of adherence to pharmacological treatments.

Electronic supplementary material

The online version of this article (doi:10.1007/s00228-016-2163-5) contains supplementary material, which is available to authorized users.

Hair analysis for opiates: hydromorphone and hydrocodone as indicators of heroin use

Background: Identification of external contamination is a challenge in hair analysis. This study investigates metabolite ratios of hydromorphone to morphine and hydrocodone to codeine as indicators to distinguish contamination from heroin use provided that hydromorphone/hydrocodone intake is excluded. Results: Hair samples after external contamination with street heroin proved to be negative for hydromorphone/hydrocodone. Hair samples from individuals with suspected street heroin use/contamination or opiate medication were analyzed for 6-monoacetylmorphine, morphine, acetylcodeine, codeine, hydromorphone and hydrocodone, and metabolite ratios of hydromorphone to morphine and hydrocodone to codeine were assessed. Hair samples from individuals with medicinal heroin/morphine/codeine use displayed significantly higher metabolite ratios than those with suspected street heroin use/contamination. Conclusion: Hydromorphone/hydrocodone are solely formed during body passage. Thus, metabolite ratios can be used to distinguish morphine/heroin use from external contamination.

Cancer pain management-current status

Cancer pain is still one of the most feared entities in cancer and about 75% of these patients require treatment with opioids for severe pain.The cancer pain relief is difficult to manage in patients with episodic or incidental pain, neuropathic pain, substance abuse and with impaired cognitive or communication skills. This non-systematic review article aims to discuss reasons for under treatment, tools of pain assessment, cancer pain and anxiety and possibly carve new approaches for cancer pain management in future. The current status of World Health Organization analgesic ladder has also been reviewed. A thorough literature search was carried out from 1998 to 2010 for current status in cancer pain management in MEDLINE, WHO guidelines and published literature and relevant articles have been included.

Sample preparation and separation techniques for bioanalysis of morphine and related substances

In present time the use or misuse of morphine and its derivatives are monitored by assaying the presence of the drug and its metabolites in biofluids. In the present review, focus is placed on the sample preparation and on the separation techniques used in the current best practices of bioanalysis of morphine and its major metabolites. However, as methods for testing the misuse of heroin, a morphine derivative, often involve bioanalytical methods that cover a number of other illicit drug substances, such methods are also included in the review. Furthermore, the review also includes bioanalysis in a broader perspective as analysis of plant materials, cell cultures and environmental samples. The review is not intended to cover all publications that include bioanalysis of morphine but is more to be considered a view into the current best practices of bioanalysis of morphine, its metabolites and other related substances.

Formation of the N-methylpyridinium derivative to improve the detection of buprenorphine by liquid chromatography-mass spectrometry

The legally defensible identification of the narcotic, analgesic buprenorphine, in biological specimen requires considerable sensitivity due to its low therapeutic dosages and corresponding target concentrations. Application of liquid chromatography-electrospray ionisation-mass spectrometry, which became the default method for buprenorphine detection, is impeded by the disadvantageous fragmentation of the stable precursor ion producing unspecific product ions of comparatively low abundance. A chemical modification to form the N-methylpyridinium ether derivative of buprenorphine is presented to improve the selectivity and sensitivity of its detection by liquid chromatography-mass spectrometry (LC-MS). The reaction of buprenorphine with 2-fluoro-1-methyl-pyridinium-p-toluene-sulfonate and triethylamine as catalyst was accomplished in acetonitrile at an ambient temperature yielding a chemically stable derivative. Fragmentation of the permanently charged precursor ion (m/z = 559) leads to the formation of diagnostic and abundant fragments (e.g. m/z = 443 and 450) representing all parts of the molecule. The application of the technique to the identification of buprenorphine in hair samples demonstrates a high specificity, availability of sufficient qualifier ions and a significant (approximately 8-fold) improvement of detection limits with respect to comparable experiments based on underivatised buprenorphine.