[Predictive value of the product of plasma colchicine concentration and poisoning time for the prognosis of colchicine poisoning patients].

Objective: To investigate the predictive value of the product of first plasmacolchicine concentration and poisoning time for the prognosis of colchicine poisoning patients, and to provide a basis for early prognosis assessment. Methods: October 2021, patients with colchicine poisoning admitted in the First Affiliated Hospitol of Wenzhou Medical University from January 2017 to September 2021 were collected, including general information such as patient gender, age, oral colchicine dose, poisoning time, the first laboratory test index andplasma colchicine concentration after admission. The patients were divided into survival group and death group according to their prognosis. The differences in clinical indicators such as admission plasma colchicine concentration, blood routine, blood biochemistry, coagulation function, and blood gas analysis were compared between the two groups, and their predictive value for the prognosis of patients were analyzed. Results: A total of 23 patients with colchicine poisoning, aged 20-85 years, were included in this study, of which 15 cases (65.22%) survived and 8 cases (34.78%) died. The first plasma colchicine concentration at admision were 0.42-53.61 ng/ml. The plasma colchicine concentration and the concentration-time product were 10.08-2147.04 h·ng/ml.Compared with the survival group, the plasma colchicine concentration and the concentration-time product in the death group were significantly increased, and the differences were statistically significant (P<0.05). Univariate logistic regression analysis showed that first plasma concentration and poisoning time>132.48 h·ng/ml, high C-reactive protein, high D-dimer, high absolute value of BE were the risk factors for the prognosis of patients with colchicine poisoning (OR=12.000, 95%CI: 1.1181-128.836; OR=1.053, 95%CI: 1.009-1.098; OR=1.219, 95%CI: 1.039-1.429; OR=1.360, 95%CI: 1.1.044-1.773; P<0.05). High prothrombin time activity was protective factor affecting the prognosis of colchicine poisoning patients (OR=0.941, 95%CI: 0.892~0.993; P<0.05). ROC curve analysis showed that the areas under the curves of first plasma concentration and poisoning time, C-reactive protein, absolute value of BE, D-dimer for predicting the prognosis of patients with colchicine poisoning were 0.918, 0.888, 0.867, 0.837, respectively, and the areas under the curves of prothrombin time activityfor predicting the prognosis of patients with colchicine poisoning was 0.788 (P<0.05) . Conclusion: The product of the first plasma colchicine concentration at admission and poisoning time is closely related to the prognosis of patients with colchicine poisoning, it can be used as a predictor for early evaluation of the prognosis of poisoned patients.

Accidental poisoning with autumn crocus (Colchicum autumnale): a case series.

INTRODUCTION: Colchicum autumnale (autumn crocus) is a plant that contains highly toxic alkaloid colchicine. The aim was to evaluate accidental C autumnale poisoning and assess serum troponin as a prognostic parameter. METHODS: In this study, we retrospectively included all adult patients with a history of accidental C autumnale ingestion and serum colchicine confirmation during the study period from 2000 to 2019. The medical files of enrolled patients were reviewed. Literature search of accidental ingestions of C autumnale was done. RESULTS: Over the study period of 20 years, 16 adult patients were admitted to the University Medical Centre Ljubljana due to acute colchicine poisoning after ingestion of C autumnale. They all mistakenly ingested C autumnale's leaves instead of Allium ursinum in the spring and had confirmed colchicine in serum by GC-MS or LC-MS/MS (15.5 µg/L (0.5-80 µg/L)). They developed vomiting and diarrhoea within 1-9 h after the meal. Vomiting within 2 h was associated with lethality (p=.04). Bone marrow suppression developed in 15 patients (94%). Acute myocardial injury with positive troponin I (>0.10 µg/L) developed in five patients; lethal cardiogenic shock with decreased cardiac output and hypotension occurred in four of these patients despite supportive therapy. Positive troponin I ultra (>0.10 µg/L) was associated with need for intensive support therapy (p=.01), decreased cardiac output (p=.01) and death (p=.01). The mortality was 4/16 (25%). On review, we found 58 cases; 95% cases accidently ingested leaves of C autumnale instead of A ursinum. Troponin I was reported in 3% cases. The lethality of this and reviewed cases was 35% (26/74). CONCLUSIONS: In unexplained gastroenterocolitis after ingestion of wild plants as a salad or spice in the spring, especially when wild garlic is mentioned, we should always consider C autumnale poisoning. Cardiogenic shock can be predicted by a positive serum troponin I measurement.

Simultaneous determination of colchicine and febuxostat in rat plasma: Application in a rat pharmacokinetic study.

A selective, sensitive and rapid LC-MS/MS method has been developed and validated as per US Food and Drug Administration regulatory guidelines for the simultaneous quantitation of colchicine and febuxostat in rat plasma. Colchicine and febuxostat were extracted from the rat plasma using 10% tert-butyl methyl ether in ethyl acetate using colchicine-d6 as an internal standard (IS). The chromatographic separation of colchicine, febuxostat and the IS was achieved using a mobile phase comprising 5 mm ammonium formate and 0.025% formic acid in acetonitrile (20:80, v/v) in isocratic mode on an Eclipse XDB-C18 column. The injection volume and flow rate were 5.0 µl and 0.9 ml/min, respectively. Colchicine and febuxostat were detected by positive electrospray ionization in multiple reaction monitoring mode using transition pairs (Q1 → Q3) of m/z 400.10 → 358.10 and 317.05 → 261.00, respectively. The assay was linear in the ranges of 0.25-254 and 2.60-622 ng/ml for colchicine and febuxostat, respectively. The inter- and intra-day precision values were 0.58-13.0 and 1.03-4.88% for colchicine and febuxostat, respectively. No matrix or carryover effects were observed during the validation. Both analytes were stable on the bench-top, in the autosampler and in storage (freeze-thaw cycles and long-term storage at -80°C). A pharmacokinetic study in rats was performed to show the applicability of the validated method.

Two fatal intoxications by colchicine taken for saffron. Clinical, medico-legal and forensic toxicological implications.

Although fatal colchicine intoxications are rare and mostly related to suicidal intake or accidental overdose, other hypotheses should be considered when dealing with colchicine poisoning. We present a case of double, acute, and subacute, fatal colchicine intoxication in a married couple. The 70-year-old male victim suddenly died after vomiting and diarrhea. The next day his wife showed aggravating gastrointestinal symptoms and was hospitalized with a diagnosis of septic shock. A complete postmortem examination on the man was performed, together with histopathological analysis. Toxicological examination performed through liquid chromatography coupled to mass spectrometry revealed a colchicine blood peripheral concentration of 33 ng/mL. A few days after hospitalization, the woman showed a colchicine plasma concentration of 32 ng/mL. Despite veno-venous hemofiltration, she ultimately died of septic shock and multi-organ failure. Death scene investigation revealed that, a few days before the death of the male victim, the couple had collected wild saffron and had eaten a presumed saffron risotto. The integrated analysis of circumstantial, clinical, postmortem and toxicological data allowed to establish that the couple had died of a fatal accidental intoxication due to the ingestion of natural colchicine, mistaken for saffron. The death of the male was deemed caused by acute cardiovascular collapse induced by acute intoxication, while the female had suffered a subacute poisoning by antimitotic agent, resulting in immunosuppression and systemic infection. Toxicological analyses, promptly performed on the man for forensic purposes, directed the investigations and suggested the clinical diagnosis on the woman.

Painless gouty tophus in the nasal bridge: A case report and literature review.

RATIONALE: A gouty tophus, arising from the deposition of monosodium urate crystals (MSU), rarely occurs in the nasal bridge. There have been only 7 documented cases of a gouty tophus in the nasal bridge from 1978 to 2018 in English-language literature. PATIENT CONCERNS: A 65-year-old male had a chief complaint of a lump in the nasal bridge that was slowly growing for over 1 year. DIAGNOSIS: MSU crystals were confirmed through ultrasonography (US) and pathological examinations. INTERVENTIONS: A cosmetically less destructive method, ultrasound-guided fine needle aspiration cytology (FNAC) was used to approach the mass lesion of nasal bridge. OUTCOMES: The diagnosis was confirmed as a gouty tophus without performing a nasal subdermal exploration. LESSONS: This case report is the first use of US with FNAC to approach and diagnosed a gouty tophus in the nasal bridge.

Epidemiology, toxicokinetics and biomarkers after self-poisoning with Gloriosa superba.

Introduction: Gloriosa superba is a flowering plant that contains colchicine. Deliberate self-poisoning with this plant in Sri Lanka is common and potentially fatal. The objective of this study was to describe the epidemiology, toxicokinetics and selected biomarkers in these patients. Materials and methods: The study consisted of three parts; epidemiologic and outcome data (n = 297), concentrations and toxicokinetics (n = 72), evaluation of urinary and serum biomarkers (n = 45). Plasma colchicine levels were measured by high-performance liquid chromatography (HPLC). We also measured serum biomarkers: creatinine (sCr), cystatin C (sCysC) and creatine kinase (CK), and urinary biomarkers: creatinine, kidney injury molecule-1 (KIM - 1), clusterin, albumin, beta-2-microglobulin (ß2M), cystatin C, neutrophil gelatinase-associated lipocalin (NGAL), osteopontin (OPN) and trefoil factor 3 (TFF3). Results: The case fatality was 10% (29/297), and death was much more common in older patients. Median concentrations of colchicine were higher in those over 65 [median 4.7 ng/mL (IQR: 1.7-6.6) vs. 1.2 (IQR: 0.2-2.7) for those <35]. Admission colchicine concentrations were highly correlated with a fatal outcome [median 7.8 ng/ml (IQR: 5.8-18.7) vs 1.2 (0-2.3) in survivors]. The area under the receiver operating characteristic curve (AUC-ROC) for uncorrected admission colchicine level was highly predictive of a fatal outcome, and this improved even further with two methods we developed to correct for the expected change with time. The best method had an AUC-ROC of 0.98 (95%CI 0.94-1.00) in predicting death, with 100% sensitivity and 96% specificity at the best cut-point. Discussion: Fatal outcomes and high concentrations were both much more common in the elderly following poisoning with Gloriosa superba. Our findings are consistent with kinetic data after medicinal colchicine ingestion. Conclusions: Gloriosa superba self-poisoning causes significant mortality. High concentration of colchicine is highly predictive of a fatal outcome. Ingestion of Gloriosa superba caused only mild acute kidney injury (AKI) and rhabdomyolysis.

Colchicine Extract Suicidal Lethal Poisoning Confirmation Using High-Resolution Accurate Mass Spectrometry: A Case Study.

A case of suspected acute and lethal intoxication caused by colchicine has been reported. The woman was hospitalized after her suspicion of suicidal poisoning by a rare autumn crocus (Colchicum autumnale). Suspected colchicine poisoning was confirmed using a novel UHPLC method with a modern reversed-phase stationary phase with a sub 2-micron superficial porous particle size combined with a QTOF mass spectrometer. Sample preparation procedure included the addition of propiverine as internal standard, protein precipitation using methanol and solid phase extraction. High-resolution MS only and targeted MS/MS modes are reported for the qualitative analysis and screening of other potential drugs of abuse in blood samples. All Ion MS mode was used for quantitative determination of colchicine afterward. The concentration of colchicine in the blood sample was approximately 41 ng/mL, and more than 200 µg/mL of the plant extract used for the suicide.

Anti-colchicine Fab fragments prevent lethal colchicine toxicity in a porcine model: a pharmacokinetic and clinical study.

BACKGROUND: Colchicine poisoning is commonly lethal. Colchicine-specific Fab fragments increase rat urinary colchicine clearance and have been associated with a good outcome in one patient. We aimed to develop a porcine model of colchicine toxicity to study the pharmacokinetics and efficacy of ovine Fab. METHODS: A Göttingen minipig critical care model was established and serial blood samples taken for colchicine and Fab pharmacokinetics, clinical chemistry, and haematology. Animals were euthanised when the mean arterial pressure fell below 45 mmHg without response to vasopressor, or at study completion. RESULTS: Initial studies indicated that oral dosing produced variable pharmacokinetics and time-to-euthanasia. By contrast, intravenous infusion of 0.25 mg/kg colchicine over 1 h produced reproducible pharmacokinetics (AUC0-20 343 [SD = 21] µg/L/h), acute multi-organ injury, and cardiotoxicity requiring euthanasia a mean of 22.5 (SD = 3.2) h after dosing. A full-neutralising equimolar Fab dose given 6 h after the infusion (50% first hour, 50% next 6 h [to reduce renal-loss of unbound Fab]) produced a 7.35-fold increase in plasma colchicine (AUC0-20 2,522 [SD = 14] µg/L/h), and removed all free plasma colchicine, but did not prevent toxicity (euthanasia at 29.1 [SD = 3.4] h). Earlier administration over 1 h of the full-neutralising dose, 1 or 3 h after the colchicine, produced a 12.9-fold (AUC0-20 4,433 [SD = 607] µg/L/h) and 6.0-fold (AUC0-20 2,047 [SD = 51] µg/L/h) increase in plasma colchicine, respectively, absence of free plasma colchicine until 20 h, and survival to study end without marked cardiotoxicity. CONCLUSIONS: Colchicine-specific Fab given early, in equimolar dose, bound colchicine, eliciting its movement into the blood, and preventing severe toxicity. Clinical studies are now needed to determine how soon this antidote must be given to work in human poisoning.

Fab fragments of ovine antibody to colchicine enhance its clearance in the rat.

CONTEXT: Colchicine is an anti-inflammatory alkaloid used for the treatment of acute gout, but has a narrow therapeutic index. Colchicine overdoses are relatively rare, but have high mortality requiring rapid treatment. OBJECTIVE: To evaluate the ability of a newly available ovine fragment antigen-binding (Fab) antibody to colchicine (ColchiFab(™)) to protect rats against renal and other injury 24 h after colchicine ingestion. MATERIALS AND METHODS: Rats were gavaged with colchicine (5 mg/kg), then 2 h later injected intraperitoneally with 5 ml of sterile saline, or Fab anti-colchicine, a newly available ovine antibody to colchicine. Samples of blood were taken at 1, 2, 5 and 24 h after gavage, and urine was collected from 5 to 24 h after gavage. Concentrations of colchicine in tissue, blood and urine were measured by liquid chromatography/mass spectrometry, concentrations of Fab anti-colchicine, urinary neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 or KIM-1 by enzyme-linked immunosorbent assay or ELISA, while concentrations of creatine kinase and creatinine (Cr) were measured enzymatically. RESULTS: Colchicine equilibrated rapidly throughout the body and increased serum creatine kinase. Fab anti-colchicine also rapidly redistributed to the blood and remained at high concentrations over 24 h. Fab anti-colchicine caused a rapid 7.1-fold increase in serum colchicine level, followed by excretion of both colchicine and Fab anti-colchicine through the urine. This was associated with the accumulation of colchicine in the kidney, a reversal of colchicine-induced diarrhoea, and increasing urinary NGAL level; from 168 ± 48 to 477 ± 255 ng/mmol Cr [mean ± standard deviation or SD]. DISCUSSION: Fab anti-colchicine greatly increased the clearance of colchicine, although increasing NGAL level suggested the presence of mild kidney damage. CONCLUSION: These data suggest clinical utility for Fab anti-colchicine in the treatment of colchicine overdose.

Colchicine levels in chronic kidney diseases and kidney transplant recipients using tacrolimus.

BACKGROUND: Tacrolimus is a CYP3A4 inhibitor and can alter colchicine metabolism. In this study, we aimed to evaluate plasma colchicine levels in different stages of kidney disease as well as in kidney transplant (KTx) recipients using tacrolimus. METHOD: This study included six familial Mediterranean fever (FMF) patients with normal glomerular filtration rate (GFR) as controls, three patients with low GFR, six FMF patients on hemodialysis (HD), and six FMF patients who were KTx recipients using tacrolimus. After a three-d washout period, plasma colchicine levels were measured at 0 (pre-dose), one, two, four, eight, and 24 h post-dose of 1 mg oral colchicine. Area under the curve 0-24 h (AUC0-24 ) and maximum concentration (Cmax ) were evaluated and compared between the groups. RESULTS: Colchicine AUC0-24 was six-fold higher in HD (p < 0.001) and three-fold higher in KTx recipients (p < 0.001) when compared to the control. The low GFR group had mildly higher AUC0-24 than the control group. Cmax levels were also higher in HD (p = 0.011) and KTx recipient (p = 0.06) groups and mildly elevated in low GFR patients in comparison with controls. CONCLUSION: Colchicine AUC0-24 and Cmax were significantly increased in HD patients and KTx recipients using tacrolimus. Therefore, dose adjustments are needed to avoid toxicity in both circumstances.

Pharmacodynamic, pharmacokinetic and tolerability evaluation of concomitant administration of lesinurad and febuxostat in gout patients with hyperuricaemia.

OBJECTIVE: The aim of this study was to evaluate the pharmacodynamics (PDs), pharmacokinetics (PKs) and safety of lesinurad (selective uric acid reabsorption inhibitor) in combination with febuxostat (xanthine oxidase inhibitor) in patients with gout. METHODS: This study was a phase IB, multicentre, open-label, multiple-dose study of gout patients with serum uric acid (sUA) >8 mg/dl following washout of urate-lowering therapy with colchicine flare prophylaxis. Febuxostat 40 or 80 mg/day was administered on days 1-21, lesinurad 400 mg/day was added on days 8-14 and then lesinurad was increased to 600 mg/day on days 15-21. sUA, urine uric acid and PK profiles were evaluated at the end of each week. Safety was assessed by adverse events, laboratory tests and physical examinations. RESULTS: Initial treatment with febuxostat 40 or 80 mg/day monotherapy resulted in 67% and 56% of subjects, respectively, achieving a sUA level <6 mg/dl. Febuxostat 40 or 80 mg/day plus lesinurad 400 or 600 mg/day resulted in 100% of subjects achieving sUA <6 mg/dl and up to 100% achieving sUA <5 mg/dl. No clinically relevant changes in the PKs of either drug were noted. The combination was well tolerated. CONCLUSION: The clinically important targets of sUA <6 mg/dl and <5 mg/dl are achievable in 100% of patients when combining lesinurad and febuxostat.

Rugged and accurate quantitation of colchicine in human plasma to support colchicine poisoning monitoring by using turbulent-flow LC-MS/MS analysis.

BACKGROUND: Colchicine is a common drug used in inflammatory diseases. The narrow therapeutic index requires fast and reliable techniques for its quantitation. An online, automated sample preparation using TurboFlow™ technology combined with triple-stage quadrupole MS detection was applied to identify colchicine in human plasma and follow intoxications. METHODOLOGY: Plasma samples (200 µl) were mixed with deuterated colchicine and protein precipitation ZnSO4 solutions. After centrifugation, supernatants were extracted onto a Cyclone P TurboFlow column and eluted onto a narrowbore Hypersil™ GOLD column with a methanol/water gradient. Analytes were monitored in SRM mode (positive electrospray). RESULTS: Total run time was 9.5 min. Calibration curves ranged from 0.342 to 17.1 ng/ml, with significant linearity (R(2) >0.99). Inter- and intra-assay precisions were <16.8% and accuracy was 84.4-110%. CONCLUSION: This method is suitable for monitoring intoxication in patients undergoing chronic treatment and is routinely applied to toxicological samples.

Body fluid and tissue analysis using filter paper sampling support prior to LC-MS/MS: application to fatal overdose with colchicine.

Because of the various matrices available for forensic investigations, the development of versatile analytical approaches allowing the simultaneous determination of drugs is challenging. The aim of this work was to assess a liquid chromatography-tandem mass spectrometry (LC-MS/MS) platform allowing the rapid quantification of colchicine in body fluids and tissues collected in the context of a fatal overdose. For this purpose, filter paper was used as a sampling support and was associated with an automated 96-well plate extraction performed by the LC autosampler itself. The developed method features a 7-min total run time including automated filter paper extraction (2 min) and chromatographic separation (5 min). The sample preparation was reduced to a minimum regardless of the matrix analyzed. This platform was fully validated for dried blood spots (DBS) in the toxic concentration range of colchicine. The DBS calibration curve was applied successfully to quantification in all other matrices (body fluids and tissues) except for bile, where an excessive matrix effect was found. The distribution of colchicine for a fatal overdose case was reported as follows: peripheral blood, 29 ng/ml; urine, 94 ng/ml; vitreous humour and cerebrospinal fluid, < 5 ng/ml; pericardial fluid, 14 ng/ml; brain, < 5 pg/mg; heart, 121 pg/mg; kidney, 245 pg/mg; and liver, 143 pg/mg. Although filter paper is usually employed for DBS, we report here the extension of this alternative sampling support to the analysis of other body fluids and tissues. The developed platform represents a rapid and versatile approach for drug determination in multiple forensic media.

Colchicine-antimicrobial drug interactions: what pharmacists need to know in treating gout.

OBJECTIVE: Review the magnitude and clinical relevance of drug-drug interactions between a new formulation of colchicine, used to treat gout, and antibiotics. SETTING AND PRACTICE DESCRIPTION: Relevant to community and institutional pharmacists servicing patients with gout. PRACTICE INNOVATION: Pharmacists have clear roles for the identification of drug-drug interactions, providing recommendations for alternative therapy or dose adjustments/modifications, and monitoring for interactionrelated adverse events. MAIN OUTCOME MEASURES: Colchicine is metabolized via cytochrome P450 3A4 (CYP3A4); therefore, coadministration with agents that inhibit this isoenzyme can produce elevated colchicine plasma concentrations, resulting in severe and sometimes fatal adverse events. Knowledge of the potential for drug-drug interactions involving antibiotics (e.g., macrolide antibiotics, azole antifungals) allows pharmacists to help patients avoid serious adverse events. RESULTS: Pharmacokinetic studies have demonstrated that the maximum plasma concentration (C(max)) and drug exposure (as assessed by area under the plasma concentration time curve [AUC]) of colchicine are increased by 277% and 282%, respectively, after coadministration with clarithromycin. Similarly, coadministration with ketoconazole increases colchicine C(max) and AUC by 102% and 212%, respectively. Other antibiotics that are strong CYP3A4 inhibitors include itraconazole and telithromycin, whereas erythromycin and fluconazole are moderate inhibitors of the isoenzyme CYP3A4. Coadministration of CYP3A4 inhibitors (particularly clarithromycin) and colchicine has resulted in acute colchicine toxicity manifested by severe gastrointestional toxicity, bone marrow suppression, multiorgan failure, and death. CONCLUSION: Pharmacist awareness of potentially clinically significant interactions between colchicine and antibiotics that inhibit CYP3A4 can help to ensure the efficacy of colchicine is realized while mitigating serious toxicities and minimizing the risk of adverse events.

Effect of cyclosporine on the pharmacokinetics of colchicine in healthy subjects.

OBJECTIVE: Colchicine and cyclosporine are often administered together, particularly in patients who have undergone solid-organ transplantation. However, the potential for drug-drug interactions between these agents resulting in colchicine toxicity is high. METHODS: This study sought to determine the effect of cyclosporine (100-mg capsule) on the pharmacokinetics of the US Food and Drug Administration-approved formulation of colchicine (0.6-mg tablet) after single oral-dose administration in 24 healthy subjects under fasted conditions in a phase 1, single-sequence, 2-period drug-drug interaction trial. RESULTS: Coadministration of cyclosporine increased colchicine maximum observed plasma concentration, area under the plasma concentration-time curve to the last measurable time point, and area under the plasma concentration-time curve to time infinity on average by 224%, 216%, and 215% (ie, almost doubled), respectively, and decreased colchicine oral clearance on average by 72% (from 48.24 to 13.42 L/h), indicating substantially higher colchicine exposures when combined with cyclosporine, compared with colchicine alone. CONCLUSION: The dose of colchicine should be reduced by ≥ 50% when colchicine and cyclosporine are administered concurrently for treatment and prophylaxis of gout flares or treatment of patients with familial Mediterranean fever. Health care professionals should be vigilant for potential adverse events during colchicine/cyclosporine coadministration, notably in patients who have undergone solid-organ transplantation. TRIAL REGISTRATION: www.ClinicalTrials.gov identifier NCT00983931 (http://clinicaltrials.gov/ct2/show/NCT00983931).

A fatal case of autumn crocus (Colchicum autumnale) poisoning in a heifer: confirmation by mass-spectrometric colchicine detection.

A heifer developed severe signs of acute gastrointestinal irritation 48 hr after ingesting fresh leaves of Colchicum autumnale growing on a damp meadow. Confirmation of the suspected toxicosis was obtained by detecting colchicine in serum and urine using liquid chromatography coupled with tandem mass spectrometry using atmospheric pressure chemical ionization. Although the serum colchicine concentration had declined to an apparently nontoxic level of 2.4 ng/ml, a more prominent concentration (640 ng/ml) indicative of colchicine poisoning was detected in the urine. This finding is consistent with the known toxicokinetic properties of colchicine, whereby a large volume of distribution results in low circulating blood concentrations and prolonged urinary excretion.

Simultaneous determination of five toxic alkaloids in body fluids by high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry.

A novel analytical method was developed and validated for the rapid and simultaneous analysis of five toxic alkaloids: Brucine, Strychnine, Ephedrine, Aconitine and Colchicine, in blood and urine using high-performance liquid chromatography-electrospray ionization tandem mass spectrometry in the multiple reaction monitoring (HPLC-ESI-MRM) mode. The linear range was 0.05-50.0 ng mL(-1) for Brucine, 0.1-50.0 ng mL(-1) for Strychnine and Ephedrine, 0.01-10.0 ng mL(-1) for Aconitine and Colchicine. The limits of quantification for Brucine, Strychnine, Ephedrine, Aconitine and Colchicine were found to be 0.03, 0.05, 0.20, 0.05, 0.01 ng mL(-1), respectively. The average extraction recoveries in urine ranged from 96.0 to 114.0% and in whole blood were 94.0 to 113.0%. The intra-day and inter-day RSDs were less than 8.3 and 10.6%, respectively. The five alkaloids could be well separated within 7 min in a single run. The established method should be suitable for the determination of trace alkaloids in body fluids.

Disposition and metabolism of the colchicine derivative [14C]-ZD6126 in rat and dog.

1. The tissue distribution, disposition and metabolism of ZD6126, a novel vascular targeting agent, were investigated in rat and dog. This paper comprises the findings of several investigations, including rat quantitative whole-body autoradiography (QWBA), rat and dog balance and metabolism (both in intact and bile-duct-cannulated animals), rat enterohepatic recirculation, and comparison of metabolism between young and mature rats. 2. Following intravenous administration of [(14)C]-ZD6126 to rats, quantitative whole-body autoradiography showed that radioactivity was widely distributed, then rapidly eliminated from the body. 3. ZD6126-related material was eliminated primarily in the faeces (approximately 86%) of both species, indicating the importance of biliary clearance. 4. Metabolite profiles from intact and bile-duct-cannulated animals suggest that ZD6126 is cleared primarily by metabolism. In rat, the major metabolites were ZD6126 phenol, its glucuronide and other metabolites consistent with O-demethylation and conjugation. ZD6126 was more extensively metabolized by male than female rats, and also in young compared with mature rats. In dog, metabolism occurred primarily via direct glucuronidation of the active species, ZD6126 phenol. 5. Following intraduodenal infusion of bile containing [(14)C]-ZD6126-related material to bile-duct-cannulated rats, 30% of the radioactivity was subsequently recovered in bile and urine, showing that one or more components in bile are reabsorbed and undergo enterohepatic recirculation.

Determination of colchicine in mouse plasma by high performance liquid-chromatographic method with UV detection and its application to pharmacokinetic studies.

A simple and sensitive high performance liquid chromatography method with UV detection was described for the determination of colchicine (COL) in mouse plasma. After single-step deproteinization by acetonitrile using berberine hydrochloride as an internal standard (I.S.), solutes were separated on a Diamonsil C(18) column (250 mm x 4.6 mm I.D., 5 microm particle size) (Dikma), using acetonitrile-0.15% phosphoric acid solution (27:73, v/v) as mobile phase (flow-rate 1.0 ml/min); wavelength of the UV detector was set at 350 nm. No interference from any endogenous substances was observed during the elution of COL and internal standard (I.S., berberine hydrochloride). The retention times for COL and I.S. were 11.23 min and 8.82 min, respectively. The limit of quantification was evaluated to be 1.5 ng/ ml and the limit of detection was 0.5 ng/ml. The method was used in the study of pharmacokinetics of COL after intravenous injection (i.v.) and intraperitoneal injection (i.p.). The result indicated that COL disappears from the plasma according to a three compartment open model.