The effect of hair color on the incorporation of codeine into human hair

The influence of melanin on the binding of xenobiotics in hair will impact the interpretation of drug concentrations determined by hair testing. The purpose of this study was to determine if codeine, as a model compound of abused drugs, would be incorporated into black, brown, blond, or red hair as a function of melanin concentration. Such data would assist in the interpretation of codeine concentrations in hair and help elucidate the potential influence of hair color on incorporation of drugs. Male and female Caucasians with black (n = 6), brown (n = 12), blond (n = 8), or red hair (n = 6) and non-Caucasians with black hair (n = 12) aged 21-40 years were enrolled in the study. Each subject was administered oral codeine phosphate syrup in a dosage of 30 mg three times a day for five days. Twenty-four hours after the end of the treatment period, a 30-mg codeine dose was administered and the subject's plasma area under the concentration time curve (AUC) for codeine was determined. Codeine and melanin were measured in the first 3 cm of hair closest to the vertex region of the scalp prior to and 1, 4, 5, 6, and 7 weeks after dosing. The quantitative and qualitative melanin profiles were determined for each subject's hair to provide an objective measure of hair color. The plasma concentrations of codeine were measured to eliminate differences in the bioavailability and clearance of codeine as factors that might account for the differences in codeine hair concentrations. The subjects were asked not to cut their hair in the vertex region of the scalp or to use any form of chemical treatment on their hair, but otherwise normal hygienic measures were permitted. The mean (+/- SE) hair codeine concentrations 5 weeks after dosing were 1429 (+/- 249) pg/mg in black hair; 208 (+/- 17) pg/mg in brown hair; 99 (+/- 10) pg/mg in blond hair; and 69 (+/- 11) in red hair pg/mg. In black hair, codeine concentrations were 2564 (+/- 170) pg/mg for Asians and 865 (+/- 162) pg/mg for Caucasians. Similar concentration relationships were observed at weeks 4, 6, and 7. A strong relationship between the hair concentrations of codeine and melanin (R(2) = 0.73) was observed. Normalization of the codeine concentration with the melanin concentration reduced the hair color differences observed. These data demonstrate that the interpretation and reporting of hair test results for codeine are influenced by hair color. After this dosing protocol, the proposed federal guideline cutoff of 200 pg/mg of codeine would result in 100% of subjects with black hair and 50% of subjects with brown hair being reported as positive, and subjects with blond or red hair would be reported as negative. The incorporation of these drugs into hair should be studied carefully in humans to ensure the appropriate interpretation of drug concentrations.     

Incorporation of doxylamine and N-doxylamine-oxide in human hair and the impact of a permanent oxidative hair dye

Knowledge of the drug incorporation in hair and impact of cosmetic treatments remains essential to correctly interpret forensic cases. The study shows the analysis of doxylamine and doxylamine-N-oxide and the evaluation of the relationship between dose and hair concentration and the impact of hair treatment (oxidative dying). The study included (A) three subjects participated to the study: a regular user (Subject 1) and two single-dose users (Subject 2, 1 single dose; and Subject 3, 2 single doses spaced 5 months apart). Subject 3 applied a permanent oxidative hair dying monthly. (B) A permanent oxidative hair dying was applied twice to the hair collected from Subject 2. (A) The average concentrations in head hair for doxylamine and its N-doxylamine-oxide, respectively, were as follows: Subject 1, 1825 pg/mg and 16 pg/mg; Subject 2, 182 and <limit of quantification (LOQ); and Subject 3, Strand 1 (1 month after last single dose]; 1st cm: 367 pg/mg and 22 pg/mg; 2nd cm: 664 pg/mg and 37 pg/mg; 3rd cm 108 pg/mg and 13 pg/mg; 4th cm 13 pg/mg and 7 pg/mg); Strand 2 (5 months after last single dose: <LOQ). (B) The oxidative hair dying increased the concentration of the metabolite from undetected <LOQ up to 79 pg/mg (n = 3, RSD 6%). The concentration of the parent drug decreased from 128 pg/mg to 40 pg/mg (n = 3, RSD 4%). This is the first time the incorporation of doxylamine and its metabolite was evaluated with adequate and controlled information concerning dose and timing of ingestion for the evaluation of their incorporation and the impact of a cosmetic treatment.     

The postoperative pharmacokinetics of codeine

Summary The metabolism and systemic availability of codeine have been studied in 12 patients after cholecystectomy. They were given 20 mg codeine as an IV bolus dose on the first day after surgery and 50 mg codeine as a single oral on the fourth day after surgery. Codeine had a medium to high extraction ratio and a total plasma clearance of 10.8 (4.3) ml·min^–1·kg^–1. The clearance varied fourfold between subjects. All the patients were extensive metabolizers with regard to the debrisoquine/sparteine polymorphism, as tested using dextromethorphan as the probe drug. Nevertheless, the formation of morphine from codeine was very small and plasma morphine concentrations were below the detection limit of 3.3 nmol·1^–1 (1 ng·ml^–1). As a corollary, the morphine/codeine ratio in the the concentration-time curves was less than 3% in all the patients.The systemic availability of codeine varied extensively between subjects (range 12–84%). This might partly explain differences in the dose of codeine required as an analgesic.     

Time-dependent codeine hypoalgesia and hyperalgesia in domestic fowl.

Recent research demonstrated that codeine produced hypoalgesia and morphine produced hyperalgesia against a noxious thermal stimulus in young domestic fowl. The bidirectional effects of these opiate agonists on nociception are inconsistent with the notion that codeine's algesic effects result through in vivo demethylation of codeine to yield morphine. In Experiment 1, the temporal pattern (15,30,60 and 120 min) of codeine (30 mg/kg) effects on thermal nociception and respiration were examined in 15-day-old cockerels. Codeine produced a time-dependent biphasic response: hypoalgesia at 15 min and hyperalgesia at 60 and 120 min. Respiration was depressed by codeine at all test intervals. To assess for opioid specificity, Experiment 2 examined the action of naloxone (5 mg/kg) on the temporal pattern (15 and 60 min) of codeine effects (30 mg/kg) on thermal nociception and respiration. Bidirectional codeine algesic effects were observed at the 15- and 60-min test intervals. Naloxone increased the codeine jump latency scores at the 15-min interval and decreased codeine jump latency scores at the 60-min interval. These results suggest that codeine engages opposed nonopioid-mediated hypoalgesic and opioid-mediated hyperalgesic nociceptive systems in this animal model. Codeine depressed respiration at both the 15- and 60-min test intervals and this respiratory depression was reversed by naloxone. These findings support the notion that codeine respiratory effects are mediated by opioid system activity.     

Identification of hydrocodone in human urine following controlled codeine administration

Allegations of illicit hydrocodone use have been made against individuals who were taking physician-prescribed oral codeine but denied hydrocodone use. Drug detection was based on positive urine opiate immunoassay results with subsequent confirmation of hydrocodone by gas chromatography-mass spectrometry (GC-MS). In these cases, low concentrations of hydrocodone (approximately 100 ng/mL) were detected in urine specimens containing high concentrations of codeine (> 5000 ng/mL). Although hydrocodone has been reported to be a minor metabolite of codeine in humans, there has been little study of this unusual metabolic pathway. We investigated the occurrence of hydrocodone excretion in urine specimens of subjects who were administered codeine. In a controlled study, two African-American and three Caucasian male subjects were orally administered 60 mg/70 kg/day and 120 mg/70 kg/day of codeine sulfate on separate days. Urine specimens were collected prior to and for approximately 30-40 h following drug administration. In a second case study, a postoperative patient self-administered 960 mg/day (240 mg four times per day) of physician-prescribed oral codeine phosphate, and urine specimens were collected on the third day of the dosing regimen. Samples from both studies were extracted on copolymeric solid-phase columns and analyzed by GC-MS. In the controlled study, codeine was detected in the first post-drug-administration specimen from all subjects. Peak concentrations appeared at 2-5 h and ranged from 1475 to 61,695 ng/mL. Codeine was detected at concentrations above the 10-ng/mL limit of quantitation for the assay throughout the 40-h collection period. Hydrocodone was initially detected at 6-11 h following codeine administration and peaked at 10-18 h (32-135 ng/mL). Detection times for hydrocodone following oral codeine administration ranged from 6 h to the end of the collection period. Confirmation of hydrocodone in a urine specimen was always accompanied by codeine detection. Codeine and hydrocodone were detected in all specimens collected from the postoperative patient, and concentrations ranged from 2099 to 4020 and 47 to 129 ng/mL, respectively. Analyses of the codeine formulations administered to subjects revealed no hydrocodone present at the limit of detection of the assay (10 ng/mL). These data confirm that hydrocodone can be produced as a minor metabolite of codeine in humans and may be excreted in urine at concentrations as high as 11% of parent drug concentration. Consequently, the detection of minor amounts of hydrocodone in urine containing high concentrations of codeine should not be interpreted as evidence of hydrocodone abuse.     

Multi‐class analysis of new psychoactive substances and metabolites in hair by pressurized liquid extraction coupled to HPLC‐HRMS

In this paper, an analytical method has been developed and validated for the analysis of new psychoactive substances (NPS) and metabolites in hair samples. The method was based on pressurized liquid extraction (PLE) followed by solid‐phase extraction (SPE) clean‐up and high performance liquid chromatography‐high resolution mass spectrometry (HPLC‐HRMS) analysis. To evaluate extraction efficiency and the applicability of the method, hair samples were fortified by soaking in order to obtain a good surrogate for drug users' hair; the amount of incorporated drugs related to their lipophilicity, similarly to in vivo drug incorporation. To the best of our knowledge, this is the first method that allowed for the analysis of both cathinones (5) and synthetic cannabinoids (7) in hair with a single extraction procedure and chromatographic run. A phenethylamine (2C‐T‐4), 4‐ fluorophenylpiperazine and methoxetamine were also included showing that PLE coupled to SPE clean‐up was suitable for a multi‐class analysis of NPS in hair. In addition, the use of PLE significantly reduced hair analysis time: decontamination, incubation, clean‐up, and liquid chromatography‐mass spectrometry (LC‐MS) analysis were carried out in approximately 45 min. The method was fully validated according to Scientific Working Group for Forensic Toxicology (SWGTOX) and Society of Hair Testing (SoHT) guidelines. Limit of quantification (LOQ) values ranged from 8 to 50 pg mg^‐1 for cathinones, phenetylamines and piperazines, and from 9 to 40 pg mg^‐1 for synthetic cannabinoids (10 pg mg^‐1 for methoxetamine). Matrix effects were below 15% for all the analytes, demonstrating the effectiveness of the clean‐up step. Inaccuracy was lower than 9% in terms of bias. Copyright © 2016 John Wiley & Sons, Ltd.     

Effect of codeine on rat and guinea pig tracheal ciliary beat frequency.

Codeine, the basic antitussive drug, has generally been thought to impair mucociliary function. Using the photodetection method the effect of codeine on mucociliary function was studied in rat after local and systemic administration and in guinea pig after systemic administration. In vitro rat tracheal ciliary beat frequency (CBF) was measured up to 40 min. There was 24.6 +/- 2.5% and 26.6 +/- 1.6% decrease in CBF after 1 mg/ml and after 10 mg/ml codeine solutions, respectively. In vivo codeine was administered in single i.v. doses of 10 and 15 mg/kg. No statistically significant differences were found in CBF responses, although there was a CBF decreasing tendency after the 15 mg/kg dose. The total follow-up time was 120 min. In guinea pig, 10 days s.c. codeine administration in daily doses of 3, 10 and 30 mg/kg had no effect on CBF. Although codeine was used in much higher concentrations than tissues concentrations after therapeutic doses of codeine, the effects on CBF were minimal. So it can be concluded that the generally accepted ciliostatic effect of codeine is overestimated.     

The impact of CYP2D6 polymorphisms on the pharmacokinetics of codeine and its metabolites in Mongolian Chinese subjects

Purpose

Codeine is an analgesic drug acting on μ-opioid receptors predominantly via its metabolite morphine formed almost exclusively by CYP2D6. Genetic polymorphisms in CYP2D6 are associated with diminished pain relief and/or severe opioid side effects. In Chinese individuals, CYP2D6*10 is the most common allele with reduced enzyme activity. In this study, we investigated the effect of this allele on the pharmacokinetics of codeine and its metabolites.

Method

A blood sample was collected from healthy Mongolian volunteers for CYP2D6 genotyping using a PCR-RFLP assay. A pharmacokinetic study was then carried out in three groups with CYP2D6*1/*1 (n?=?10), CYP2D6*1/*10 (n?=?10) and CYP2D6*10/*10 (n?=?9) genotypes by collecting serial blood samples for determination of plasma levels of codeine and its metabolites, morphine, morphine 3-glucuronide (M3G) and morphine 6-glucuronide (M6G) before and after a single 30-mg oral dose of codeine phosphate. Codeine and its metabolites were measured by LC-MS/MS.

Results

No significant differences were observed in the pharmacokinetic parameters of codeine in the three genotype groups. However, the C _max and AUC_0-∞ of morphine, M3G and M6G were significantly different between the study groups (P?<?0.05). Compared with the *1/*1 group, the AUC_0-∞ for morphine in the *1/*10 and *10/*10 groups decreased by ratios (95 % CI) of 0.93 (0.26–1.59) and 0.494 (0.135–0.853) respectively. Corresponding ratios for M3G were 0.791 (0.294–1.288) and 0.615 (0.412–0.818) and for M6G were 0.643 (0.39–0.957) and 0.423 (0.267–0.579).

Conclusion

This study demonstrates that the CYP2D6*10 allele plays an important role in the pharmacokinetics of the O-demethylated metabolites of codeine after oral administration.     

Hair analysis for Δ9‐tetrahydrocannabinolic acid A (THCA‐A) and Δ9‐tetrahydrocannabinol (THC) after handling cannabis plant material

A previous study has shown that Δ⁹‐tetrahydrocannabinolic acid A (THCA‐A), the non‐psychoactive precursor of Δ⁹‐tetrahydrocannabinol (THC) in the cannabis plant does not get incorporated in relevant amounts into the hair through the bloodstream after repeated oral intake. However, THCA‐A can be measured in forensic hair samples in concentrations often exceeding the detected THC concentrations. To investigate whether the handling of cannabis plant material prior to consumption is a contributing factor for THC‐positive hair results and also the source for THCA‐A findings in hair, a study comprising ten participants was conducted. In this study, the participants rolled a marijuana joint on five consecutive days and hair samples of each participant were obtained. Urine samples were taken to exclude cannabis consumption prior to and during the study. THCA‐A and THC could be detected in the hair samples from all participants taken at the end of the exposure period (concentration range: 15–1800 pg/mg for THCA‐A and < 10–93 pg/mg for THC). Four weeks after the first exposure, THCA‐A could still be detected in the hair samples of nine participants (concentration range: 4–57 pg/mg). Furthermore, THC could be detected in the hair samples of five participants (concentration range: < 10–17 pg/mg). Based on these results, it can be concluded that at least parts of the THC as well as the major part of THCA‐A found in routine hair analysis derives from external contamination caused by direct transfer through contaminated fingers. This finding is of particular interest in interpreting THC‐positive hair results of children or partners of cannabis users, where such a transfer can occur due to close body contact. Analytical findings may be wrongly interpreted as a proof of consumption or at least passive exposure to cannabis smoke. Such misinterpretation could lead to severe consequences for the people concerned. Copyright © 2015 John Wiley & Sons, Ltd.     

A dose-ranging study of the pharmacokinetics of codeine phosphate following intravenous administration to rats

The linearity of the pharmacokinetics of codeine was examined in male Sprague-Dawley rats given iv bolus doses of 1, 1.5, 3, and 4 mg/kg of codeine phosphate. Codeine and morphine were determined in serial blood samples utilizing HPLC with electrochemical detection. Codeine exhibits characteristics consistent with a two-compartment pharmacokinetic model. The kinetics of codeine are linear in the iv dose range 1-4 mg/kg. The ratio AUCmorphine:AUCcodeine increases disproportionately with increasing doses of codeine.     

Behavior maintained by intravenous injection of codeine,cocaine, and etorphine in the rhesus macaque and the pigtail macaque

Lever-pressing behavior of two species of macaque, the rhesus macaque (M. mulatta) and the pigtail macaque (M. nemestrina) was maintained by intravenous injection of codeine, etorphine, or cocaine. Monkeys responded under a fixed-ratio 30 timeout 600 s schedule of drug injection during two daily experimental sessions. Drug-maintained behavior was studied under two access conditions. Under the first condition, selected doses of codeine or cocaine were available for ten consecutive sessions. Under the second condition, responding was maintained by 0.32 mg/kg codeine or 0.32 mg/kg cocaine, and saline and selected doses of codeine, etorphine, and cocaine were substituted during single experimental sessions. Performance varied with drug and injection dose, access condition, and macaque species. For all three drugs, response rate increased and then decreased as injection dose increased. Maximal rates were maintained by 0.10–0.32 mg/kg codeine, 0.0003–0.001 mg/kg etorphine, and 0.10–0.32 mg/kg cocaine. A cocaine dose of 0.32 mg/kg maintained higher rates than any dose of codeine or etorphine, and maintained higher rates when available during consecutive sessions than when substituted for codeine for a single session. Codeine maintained similar rates under all access conditions. The pigtail macaques had short catheter lives, did not readily acquire codeine-maintained responding, and displayed lower rates of drug-maintained lever pressing than the rhesus macaques.     

The effects of methylnaltrexone alone and in combination with acutely administered codeine on gastrointestinal and colonic transit in health

Aliment Pharmacol Ther 2010; 32: 884–893

Summary

Background The short‐term effects of methylnaltrexone (MNTX), a peripherally acting μ‐opioid receptor antagonist, on gastrointestinal and colonic transit remain unclear. Aim To compare the effects of placebo, codeine, subcutaneous (s.c.) MNTX and codeine with s.c. MNTX on gastrointestinal and colonic transit of solids in healthy humans. Methods In a randomized, parallel‐group, double‐blind, placebo‐controlled trial of 48 healthy volunteers, effects of 6 consecutive days of placebo [s.c. and p.o. (orally), n = 8], codeine (p.o. 30 mg q.d.s., n = 8), MNTX (s.c. 0.30 mg/kg, n = 16) and combined MNTX and codeine (same doses and routes, n = 16) on gastrointestinal and colonic transit were assessed. A validated scintigraphic method was used to measure transit during the last 48 h of treatment. Bowel function was estimated during treatment as well as 1 week preceding treatment using standard diaries. Analysis of covariance was used to assess treatment effects. Results Codeine delayed colonic transit [geometric centre at 24 h (P = 0.04) and ascending colon t_1/2 (P = 0.02)] and reduced stool frequency (P = 0.002), but had no effect on stool form. MNTX did not affect transit, stool frequency or stool form, either alone or with codeine (P > 0.3). No drug interaction effects were detected (P > 0.15). Conclusion Methylnaltrexone does not alter gastrointestinal or colonic transit and does not reverse acute codeine‐associated delayed gut transit in health.     

Chlorpromazine in human scalp hair as an index of dosage history: comparison with simultaneously measured haloperidol

Summary The concentration of chlorpromazine (CPZ) in hair was measured to demonstrate its value as an index of individual dosage history and compliance. An animal study using pigmented rats was conducted to confirm the dose-dependent accumulation of CPZ in hair. The concentration of CPZ in hair, newly regrown on a denuded area of the back after the administration of CPZ for 3 weeks, was 4.6, 8.5 and 16.6 ng·mg^–1 hair after daily doses of 1.25, 2.5 and 5 mg·kg^–1·day^–1, respectively, significantly correlated with the daily dose.The concentration of CPZ in black hairs collected from 23 Japanese patients, who had been taking CPZ in fixed daily doses (30–300 mg/day), ranged from 1.6 to 27.5 ng·mg^–1, and was significantly correlated both with the daily dose and with the trough plasma concentration at steady state. Several strands of hair collected from each of 5 patients, whose doses of CPZ had been changed within several months before sampling, were cut into 1-cm pieces successively from the scalp end and the concentration of CPZ in each piece was measured. With the assumption of a hair growth rate of 1 cm per month, the individual history of CPZ doses in all patients could be deduced from the distribution of CPZ along the hair shaft. In 5 patients with grizzled hair the concentration of CPZ in white hairs was much lower (<10%) than in black hairs, suggesting that the strong affinity of CPZ for hair melanin may explain the accumulation of CPZ in black hair.The concentration of co-administered haloperidol (HP) in plasma and hair was also measured in 11 out of 23 patients. The CPZ concentration in hair was much lower than that of HP (about 0.3 to 7.8%), whether the comparison was made on the basis of daily dose or plasma concentration. This finding is discussed in relation to the affinity of the compounds for their melanin and photochemical stability.     

Opiate recidivism in a drug-treatment program: comparison of hair and urine data

The objective of this preliminary study was to determine whether hair can be used as an adjunct specimen for the monitoring of opiate use in a drug-treatment program. Subjects (n = 10) initiating clinical therapy for opiate addiction were monitored for up to 17 weeks with hair and urinalysis. Questionnaires were administered weekly to document hair cuts and chemical treatments. Hair specimens were collected weekly by cutting at the scalp and segmented into 1-cm lengths prior to analysis. Codeine (COD), morphine (MOR), and 6-monoacetylmorphine (6-MAM) concentrations in hair were measured by liquid chromatography-mass spectrometry (LC-MS) [limit of detection (LOD): 20 pg/mg for COD and 6-MAM; 50 pg/mg MOR]. Urine specimens were analyzed by semiquantitative radioimmunoassay (25-ng/mL cutoff) and LC-MS for codeine (COD), morphine (MOR), morphine-3beta-glucuronide (M3G), morphine-6 beta-glucuronide (M6G), and 6-monoacetylmorphine (6-MAM). The LOD and limit of quantitation (LOQ) in urine for COD, M3G, M6G, and 6-MAM were 10 ng/mL and 25 ng/mL for MOR. Interpretation of the segmental hair data in this study was complex and generally was not in agreement with urine data in most cases. Evaluation of hair data suggested that 6 of 10 subjects discontinued opiate use by the end of the study, whereas 3 of 10 appeared to have reduced their use. One subject appeared not to have used opiates throughout the entire study. In contrast, evaluation of urine data suggested that only 4 of 10 subjects significantly reduced use, and 6 of 10 continued drug use on at least an intermittent basis. Urine appeared to be a more sensitive indicator of changes in the pattern(s) of drug use during the course of clinical drug treatment.     

毛发中度冷丁及其代谢产物的鉴定

目的：为考察度冷丁滥用者毛发中度冷丁及其代谢物的存在状况,建立GC/MS和GC/NPD测定人毛发中度冷丁及代谢产物去甲度冷丁的定性定量分析方法。方法：毛发经酸水解后用乙醚直接提取,GC/MS和GC/NPD测定。结果：度冷丁及去甲度冷丁回收率>80%,最低检出限分别为0.5 ng.mg^-1和1 ng.mg^-1。在度冷丁滥用者毛发中鉴定、确认度冷丁及其代谢物去甲度冷丁、乙酰去甲度冷丁,并测定了50例度冷丁滥用者毛发中度冷丁及去甲度冷丁的浓度,分别为4.8～496 ng.mg^-1和15.5～685 ng.mg^-1。结论：方法简便、可靠、灵敏,可作为法医鉴定和临床诊断的工具。     

Drug testing with alternative matrices II. Mechanisms of cocaine and codeine deposition in hair.

A 10-week inpatient study was performed to evaluate cocaine, codeine, and metabolite disposition in biological matrices collected from volunteers. An initial report described drug disposition in plasma, sebum, and stratum corneum collected from five African-American males. This report focuses on drug disposition in hair and sweat collected from the same five subjects. Following a three-week washout period, three doses of cocaine HCl (75 mg/70 kg, subcutaneous) and three doses of codeine SO4 (60 mg/70 kg, oral) were administered on alternating days in week 4 (low-dose week). The same dosing sequence was repeated in week 8 with doubled doses (high-dose week). Hair was collected by shaving the entire scalp once each week. Hair from the anterior vertex was divided into two portions. One portion was washed with isopropanol and phosphate buffer; the other portion was not washed. Hair was enzymatically digested, samples were centrifuged, and the supernatant was collected. Sweat was collected periodically by placing PharmChek sweat patches on the torso. Drugs were extracted from sweat patches with methanol/0.2 M sodium acetate buffer (75:25, v/v). Supernatants from hair digests, hair washes, and sweat patch extracts were processed by solid-phase extraction followed by gas chromatography-mass spectrometry analysis for cocaine, codeine, 6-acetylmorphine, and metabolites. Cocaine and codeine were the primary analytes identified in sweat patches and hair. Drugs were detected in sweat within 8 h after dosing, and drug secretion primarily occurred within 24 h after dosing. No clear relationship was observed between dose and drug concentrations in sweat. Drug incorporation into hair appeared to be dose-dependent. Drugs were detected in hair within 1-3 days after the last drug administration; peak drug concentrations generally occurred in the following 1-2 weeks; thereafter, drug concentrations decreased. Solvent washes removed 50-55% of cocaine and codeine from hair collected 1-3 days after the last drug dose. These data may reflect removal of drug that was deposited by sweat shortly after dosing. Drug removed by washing hair collected 1-3 weeks after the last dose was minimal for cocaine but variable for codeine. Drug in these specimens was likely transferred from blood to germinative hair cells followed by emergence of drug in growing hair. These findings suggest that drug deposition in hair occurs by multiple mechanisms.     

Codeine and morphine in extensive and poor metabolizers of sparteine: pharmacokinetics,analgesic effect and side effects

Objective: Codeine O-demethylation to morphine is catalysed by the genetic polymorphic sparteine oxygenase (CYP2D6). The objective of the present study was to assess the analgesic effect of codeine on different types of experimental pain in relation to sparteine phenotype. Methods: Fourteen extensive (EMs) and 14 poor metabolizers (PMs) of sparteine completed a randomized, double-blind, three-way, cross-over study with a single oral dose of codeine (75 or 100?mg) against morphine (20 or 30?mg) and placebo. Pain tests performed before and 1,?2,?3, and 4?h after medication included the cold pressor test and pain thresholds for heat and pressure stimulation. Adverse effects were rated by a structured interview. Results: After morphine, morphine and morphine-6-glucuronide were present in equal amounts in plasma of PMs and EMs. After codeine, neither morphine nor morphine-6-glucuronide could be detected in 13 of the 14 PMs, whereas at least one of the compounds could be detected in all EMs. Peak pain and discomfort rated on a VAS scale during the cold pressor test were significantly reduced by morphine in both EMs and PMs, with a median peak change of 8.5 and 7.0?mm, respectively, for peak pain, and 11.5 and 15.5?mm, respectively, for discomfort. Codeine only reduced these pain measures significantly in EMs, with a median peak change of 5.5?mm for peak pain and 10.5?mm for discomfort. Pain detection and tolerance thresholds to heat and pressure were not consistently altered by either morphine or codeine. In PMs, adverse effects were significantly more pronounced on morphine than on codeine and only showed a slight difference between codeine and placebo. In EMs, there was no difference between codeine and morphine and more pronounced adverse effects on both drugs as compared to placebo. Conclusions: This study confirms that codeine O-demethylation depends on CYP2D6; it shows that the 6-glucuronidation of morphine is independent of CYP2D6; it supports the theory that the analgesic effect of codeine depends on its O-demethylation; and it indicates that this is probably also the case for the adverse effects. The resuls lend no support to the suggestion of a non-opioid analgesic effect of codeine.     

Analysis of ethyl glucuronide in hair samples by liquid chromatography‐electrospray ionization–tandem mass spectrometry (LC‐ESI‐MS/MS)

Many different biomarkers can be used to evaluate ethanol intake. Ethyl glucuronide (EtG) is a direct phase II and minor metabolite of ethanol formed through the UDP‐glucuronosyl transferase‐catalyzed conjugation of ethanol with glucuronic acid. Its investigation is of interest in both clinical and forensic contexts because of the wide window of detection. A sensitive LC‐MS/MS procedure has been developed and fully validated according to the guidelines of forensic toxicology for the analysis of EtG in hair. Sample preparation and chromatographic separation were thoroughly optimized. The analysis was performed in the multiple reaction monitoring mode using the transitions m/z 221 → 203 (for the quantification) and 221 → 85 or 75 (for the qualification) for EtG, and m/z 226 → 208 (for quantification) and 226 → 75 or 85 (for qualification) for EtG‐D5, used as the internal standard. Analyses were carried out using an Inertsil ODS‐3 column (100 × 3 mm i.d., 3 µm particle size) and a mobile phase composed of formic acid and acetonitrile. Various SPE cartridges and solvents were tested in order to obtain the highest recoveries and cleanest extracts. The assay linearity of EtG was confirmed over the range from 20 to 2500 pg mg^?1, with a coefficient of determination (R²) above 0.99. The lower limit of quantitation (LLOQ) was 20 pg mg^?1 and the limit of detection was 10 pg mg^?1. Intra‐ and inter‐day assays were less than 15% except at the LLOQ (20%). The analytical method was applied to 72 post‐mortem hair samples. EtG concentration in the hair ranged from 0 to 653 pg mg^?1 hair. Copyright © 2012 John Wiley & Sons, Ltd.     

Pharmacokinetics and safety of JTP-4819, a novel specific orally active prolyl endopeptidase inhibitor, in healthy male volunteers

Aims To investigate the pharmacokinetics and safety profile of JTP-4819, (-)-(2S)-1-benzylaminocarbonyl-[ (2S)-2-glycoloylpyrrolidinyl]-2-pyrrolidinecarboxamide, a novel specific orally active prolyl endopeptidase (PEP) inhibitor. Methods JTP-4819 was given orally to 28 healthy male volunteers at single doses of 30 mg (n=6), 60 mg (n=6), 120 mg (n=6) and placebo (n=3) and multiple doses of 60 mg three times daily (n=5) and placebo (n=2) for 7 days to investigate its safety and pharmacokinetics following a preliminary safety evaluation of 3, 10 and 30 mg doses in six healthy volunteers. With the single dose of 60 mg, a cross-over study was conducted to examine the effect of food on the bioavailability of the drug. The concentrations of JTP-4819 in plasma and urine were determined by electrospray ionization-liquid chromatography/mass spectrometry (ESI-LC/MS) method. Results In the multiple–dose study, the cholinesterase activity was gradually increased and reached above the normal range on days 4 to 8 in all five subjects given JTP-4819 and gradually returned to normal range after completion of dosing. The elevation of plasma cholinesterase activity was considered to be an action of JTP-4819, but this remains to be verified. There were no other abnormal findings in objective symptoms and laboratory findings including blood pressure, heart rate, electrocardiogram, body temperature, haematology, blood chemistry and urinalysis. The C_max of JTP-4819 at 30, 60 and 120 mg in fasting state were 474, 887 and 1,649 ng ml⁻¹, respectively, at 1 h after administration, and the t_1/2 was about 2 h. AUC increased in proportion to the given doses. The cumulative urinary recoveries within 24 h were approximately 66%. C_max, AUC, t_1/2 and urinary recovery were not affected by food intake. In the multiple-dose study, there was no drug accumulation trend in plasma. Conclusions These results indicate that JTP-4819 has acceptable pharmacodynamic and pharmacokinetics profiles for clinical use without any serious adverse events as we verified in healthy young male volunteers.