In vivo interactions between BZP and TFMPP (party pill drugs)

AIM

This study explores potential drug-drug interactions between BZP and TFMPP. This was achieved by comparing the metabolism and pharmacokinetics of BZP and TFMPP when taken together with previously published data on their individual metabolism and pharmacokinetics.

METHOD

Blood and urine samples were collected from seven participants given a combined dose of BZP (100 mg) and TFMPP (30 mg) and analysed by LC-MS in order to quantify the concentrations of BZP, TFMPP, and their major hydroxylated metabolites 3-OH BZP, 4-OH BZP, and 4-OH TFMPP.

RESULTS

The metabolic profiles of both drugs were altered when co-administered. Both BZP and TFMPP lost one metabolite, 3-OH BZP and 4-OH TFMPP, respectively. Some differences in the pharmacokinetic properties of TFMPP were also noted.

CONCLUSION

Metabolic interactions between BZP and TFMPP are clearly observed in this study along with some changes to the pharmacokinetics of TFMPP. As these drugs are often co-administered, the interactions between them are both relevant and concerning. Awareness of these interactions can assist clinicians in understanding toxicities relating to the co-administration of BZP and TFMPP or other party pill drugs.

[Doping. High-tech cheating in sport]

Today, doping is no longer limited to the classical drugs with well known effects and side effects. Older generation anabolic steroids are used mainly in fitness and recreational sports. In contrast, due to doping tests, substances used in competitive sports include peptide hormones, medications not yet approved, and even specially developed drugs, such as designer steroids. Of the peptide hormones, particularly growth hormones (human growth hormone), erythropoietin and generics, insulin, and presumably insulin-like growth factor 1 are used. Substance groups potentially relevant for doping are selective androgen receptor modulators and gene therapy drugs. For most of these, there is no knowledge about side effects in healthy individuals, and no adequate doping tests. Therefore, anti-doping measures cannot rely solely on the continual improvement of doping analyses, but should include increased measures for doping prevention. Not only sports organizations, but also governmental agencies should be involved in developing and implementing these measures.

[Analysis on the abused drugs in saliva and correlation of saliva drugs concentrations with blood concentrations]

Saliva is an easily collected body fluid and has simple composition. Some drugs concentrations in saliva can reflect their blood level. This paper analyzes the mechanisms of drug transfer from blood into saliva and the influencing factors, reviews the methods of sample collection, preparation, analysis of the abused drugs in saliva, and the relationship between abused drugs content in saliva and in blood. We believe that saliva is a valuable sample in clinic and forensic medicine. It is important in forensic science field to estimate abused drugs concentrations in blood by via their saliva concentrations.

Recent paramethoxymethamphetamine (PMMA) deaths in Taiwan

Paramethoxyamphetamine (PMA) and paramethoxymethamphetamine (PMMA) are methoxylated phenylethylamine derivatives that have been banned in Taiwan since December 2005. The case history and pathological and toxicological findings of eight recent PMMA fatalities were investigated. All specimens from these cases were initially identified by an AxSYM fluorescence polarization immunoassay screening test for amphetamines with a 300 ng/mL cutoff. Specimens screened positive were confirmed and quantitated by gas chromatography-mass spectrometry. The mean age of these PMMA-related fatalities was 18.9 +/- 4.4 years in the range of 14-25. Seven (87.5%) of these eight cases were men. The mean, standard deviation, and range of PMA found in the heart blood collected from these 8 cases were 0.213, 0.144, and 0.079-0.489 microg/mL, respectively. The corresponding data for PMMA were 4.312, 4.806, and 1.208-15.824 microg/mL, respectively. Other drugs, such as MDA, MDMA, ketamine, norketamine, hydroxymidazolam, methamphetamine, and pentobarbital, were also found in these cases.

Detection of gamma-hydroxybutyrate in striatal microdialysates following peripheral 1,4-butanediol administration in rats

The illicit use and abuse of 1,4-butanediol (1,4-BD) results from its presumed conversion to gamma-hydroxybutyrate (GHB) and subsequent pharmacological effects via action on GABA-B and GHB-specific receptors. Using in vivo microdialysis we measured the appearance of GHB in the striata of rats after peripheral 1,4-BD administration. We developed and utilized an HPLC-UV (215 nm) detection of GHB that yielded a limit of quantification (S/N=10) of 2.0 micro g/mL (40 ng/injection) and a limit of detection (S/N=3) of 0.75 micro g/mL (15 ng/injection). GHB appeared in the striatal microdialysates within 20 min after intraperitoneal (i.p.) administration of varying doses of 1,4-BD. GHB concentrations reached dose-dependent maxima 80-100 min post-1,4-BD administration, with peak values of 10.6+/-2.9, 25.3+/-3.4 and 48.1+/-7.1 micro g/mL (mean+/-S.E.M.), corresponding to 1,4-BD doses of 250, 500 and 750 mg/kg, respectively. The conversion of 1,4-BD to GHB was completely prevented by the alcohol dehydrogenase inhibitor 4-methylpyrazole (4MP), administered prior to 1,4-BD, as evidenced by the failure of GHB to appear in the striatal microdialysates. Sleep times in animals were similarly correlated with GHB concentrations in the microdialysates.

Toxicokinetics of drugs of abuse: current knowledge of the isoenzymes involved in the human metabolism of tetrahydrocannabinol, cocaine, heroin, morphine, and codeine

This review summarizes the major metabolic pathways of the drugs of abuse, tetrahydrocannabinol, cocaine, heroin, morphine, and codeine, in humans including the involvement of isoenzymes. This knowledge may be important for predicting their possible interactions with other xenobiotics, understanding pharmaco-/toxicokinetic and pharmacogenetic variations, toxicological risk assessment, developing suitable toxicological analysis procedures, and finally for understanding certain pitfalls in drug testing. The detection times of these drugs and/or their metabolites in biological samples are summarized and the implications of the presented data on the possible interactions of drugs of abuse with other xenobiotics, ie, inhibition or induction of individual polymorphic and nonpolymorphic isoenzymes, discussed.

Solid-Phase Microextraction: Investigation of the Metabolism of Substances that May be Abused by Inhalation

Purified liquefied petroleum gas (LPG), a mixture of butane, isobutane, and propane, is commonly abused by inhalation. Little is known about the mammalian metabolism of these substances. Metabolism of other hydrocarbons, including n-hexane and cyclohexane, has been studied in vitro using a range of liver preparations, with metabolites analyzed by static headspace techniques. Solid-phase microextraction (SPME) for sampling metabolites in the headspace of incubates of volatile compounds with activated rat liver microsomes is investigated. Cyclohexanol and cyclohexanone were formed from cyclohexane and 1-, 2-, and 3-hexanol and 2-hexanone from n-hexane as predicted. Secondary alcohols are found for the other compounds studied, except for propene and isobutane, together with 2-propanone and 2-butanone from propane and n-butane, respectively. Samples from three individuals who died following LPG abuse contained a range of putative n-butane metabolites: n-butanol, 2-butanol, 2,3-butanediol, 3-hydroxy-2-butanone, and 2,3-butanedione. To our knowledge, the last three compounds have not been proposed as metabolites of n-butane in man. These might be produced through similar metabolic pathways to those of n-hexane and n-heptane. The findings indicate the value of SPME for investigating the metabolism of volatile substances and for detecting and monitoring exposure to these compounds.

[Investigations concerning the threshold value between endogenous and exogenous GHB (liquid ecstasy)]

The article describes critical investigations concerning the threshold value between endogenous and exogenous concentrations of gamma-hydroxybutyric acid (GHB/"liquid ecstasy") in human blood. The values of GHB in the blood samples of 50 blood donors and 50 postmortem cases were measured with a validated gas-chromatographic/mass-spectrometric procedure according to the guidelines of the GTFCh (Society of Toxicological and Forensic Chemistry). GHB-concentrations were found to range between 0.11 and 1.56 mg/L (mean value 0.54 mg/L/standard deviation 0.37 mg/L/coefficient of variation 68.4 %) in the donors' blood, and between 2.2 and 116 mg/L (mean value 32.4 mg/L/standard deviation 25.6 mg/L/coefficient of variation 79 %) in the postmortem samples, respectively.

[Breast-feeding and drugs of abuse]

Drugs of abuse in breast-feeding women and the risk for the baby represent a problem of great concern both from a medical as well as of ethical point of view. Possibilities for the determination of the levels of exposure are discussed. Analysis of the risk for the infant exposure to drugs of abuse excreted in the breast milk is done. The effects of the most important drugs of abuse on breast-fed babies are reviewed.

Gamma-hydroxy butyric acid: Neurotransmitter, sedative and party drug

Gamma-hydroxybutyric acid (GHB) as a natural component of the mammalian brain was first introduced in clinical anaesthesic practice more than 40 years ago. The drug was nearly forced from clinical practice because of its prolonged and variable duration of action. The results of recent clinical studies indicate a re-evaluation of GHB in various clinical fields. In the intensive care unit, GHB may be a favourable alternative to established drugs. The results of various clinical studies also suggest that GHB is efficacious in the treatment of alcohol withdrawal syndrome, and narcolepsy. GHB has been used successfully for short-term sedation in children. In addition, GHB has emerged as a street drug ("liquid ecstasy"). Overdose may lead to respiratory depression, coma, and even death. Chronic abuse itself may lead to severe withdrawal syndrome. The purpose of this article is to outline the neurophysiological, pharmacodynamic and pharmacokinetic characteristics of GHB, and to summarize the potential fields of use and misuse of GHB in clinical medicine and toxicology.

Med-psych drug-drug interactions update. Antiretrovirals, part III: antiretrovirals and drugs of abuse

The third in a series reviewing the HIV/AIDS antiretroviral drugs, this report summarizes the interactions between antiretrovirals and common drugs of abuse. In an overview format for primary care physicians and psychiatrists, the metabolism and drug interactions in the context of antiretroviral therapy are presented for the following drugs of abuse: alcohol, benzodiazepines, cocaine, GHB (liquid X), ketamine (special K), LSD (acid), MDMA (Ecstasy), opiates, PCP (angel dust), and THC (marijuana).

Review: Pharmacokinetics of illicit drugs in oral fluid

This article reviews studies that have measured drug concentrations in oral fluid following controlled dosing regimens. A total of 23 studies have been identified over the last 15 years. These show that the amphetamines including designer amphetamines, cocaine, cannabis and cocaine are quickly found in oral fluid following dosing and usually have similar time-courses to that in plasma. Following common doses peak oral fluid concentrations exceed 0.1 microg/mL and often even 1 microg/mL. The drug concentration will depend on whether a dilution step occurs with buffer as part of the sampling procedure. The uses of collectors that stimulate oral fluid usually reduce the drug concentration compared to a non-stimulated manner. This reduction will not disadvantage the recipient since it will potentially reduce the detectability of drug in oral fluid compared to non-stimulated collections. Only one recent study has been reported for a benzodiazepine. This showed nanogram per milliliter concentrations for flunitrazepam. More studies are required for benzodiazepines and indeed for other drugs, particularly in multiple drug situations and where disease may affect the pharmacokinetics of drugs.

Oral methylphenidate challenge selectively decreases putaminal T2 in healthy subjects

Despite the recent rise in oral methylphenidate (MPH) abuse, few studies have characterized the time course of oral MPH brain effects in human subjects. Accordingly, this study assessed the hemodynamic effects of oral MPH effects in 11 healthy young adults (six women), by measuring brain transverse relaxation times (T2). T2 can be interpreted as a surrogate marker for, and inversely correlated with, steady-state cerebral blood volume (CBV). Data were acquired from the caudate nucleus, putamen, and thalamus, using a 1.5 T MRI scanner at baseline and serially for 2 h following oral MPH administration (0.5 mg/kg). Physiological and subjective measures and plasma MPH levels also were examined. MPH induced a selective T2 decrease (-1.65+/-0.53 ms) in the putamen (F(6,54)=2.68, P<0.03). Heartrate, blood pressure and plasma MPH levels increased significantly after drug administration, as well as subjective ratings of "feeling drug effect". T2 decreases may reflect MPH-induced increases in putaminal blood volume. These data suggest that T2 relaxometry can be used to study the time course of regional cerebral blood volume responses to MPH and perhaps to other stimulant drugs.

Recreational use of sildenafil by HIV-positive and -negative homosexual/bisexual males

OBJECTIVE

To conduct an epidemiologic review of sildenafil in homosexual and bisexual males focusing on concurrent use with club drugs and/or antiretroviral medications.

DATA SOURCES

A search of MEDLINE was conducted (1966-September 2003), and an extensive manual review of journals was performed using the key search terms club drugs, sildenafil, antiretrovirals, and HIV.

STUDY SELECTION AND DATA EXTRACTION

All articles identified from the data sources were evaluated and information deemed relevant was included.

DATA SYNTHESIS

Several epidemiologic studies have reported that sildenafil is abused in a recreational fashion, typically with agents commonly known to be "club drugs." In this setting, sildenafil may reverse the impotence-inducing effects of the club drugs and restore sexual capabilities. Many implications of both recreational and nonrecreational use of sildenafil exist in relation to HIV disease. Concern has been raised regarding the potential effects on high-risk sexual practices. Also, several researchers have documented interactions between sildenafil and various club drugs, as well as with antiretrovirals intended for HIV disease.

CONCLUSIONS

Serious concerns exist regarding the concurrent use of sildenafil with antiretrovirals and/or club drugs. Clinicians prescribing sildenafil to patients receiving protease inhibitor-containing antiretroviral regimens should be aware of the potential for reduced sildenafil metabolism with resultant adverse effects. Additionally, untoward effects may also occur when sildenafil is used concurrently with various club drugs including amyl and butyl nitrites ("poppers").

Recent progress in pharmacokinetic applications of capillary electrophoresis

This review is a continuation of the previous reviews (Electrophoresis 1999, 20, 3259-3268; Electrophoresis 2001, 22, 4244-4248) to update the recent publications from 2001 to 2003 on pharmacokinetic studies using capillary electrophoresis (CE). During this period of time, CE remains as a unique analytical method for some studies, which would otherwise be limited by many factors, such as the sample volume, detection sensitivity, or separation power. It is particularly noticeable that the separation of chiral drugs in biological sample and the use of solid-phase extraction (SPE) as a simple and convenient means of sample preparation appear to become popular for CE-based assays. The use of CE for assessing complete pharmacokinetic information, however, did not show a significant growth during this period of time. In order to provide a broad range of view on how biological samples are analyzed by CE, this review will cover publications during the past two years on the use of CE for the analysis of drugs in biological fluids for general pharmacokinetic applications including drug monitoring and bioavailability studies.

Interactions between recreational drugs and antiretroviral agents

OBJECTIVE

To summarize existing data regarding potential interactions between recreational drugs and drugs commonly used in the management of HIV-positive patients.

DATA SOURCES

Information was obtained via a MEDLINE search (1966-August 2002) using the MeSH headings human immunodeficiency virus, drug interactions, cytochrome P450, medication names commonly prescribed for the management of HIV and related opportunistic infections, and names of commonly used recreational drugs. Abstracts of national and international conferences, review articles, textbooks, and references of all articles were also reviewed.

STUDY SELECTION AND DATA EXTRACTION

Literature on pharmacokinetic interactions was considered for inclusion. Pertinent information was selected and summarized for discussion. In the absence of specific data, prediction of potential clinically significant interactions was based on pharmacokinetic and pharmacodynamic properties.

RESULTS

All protease inhibitors (PIs) and nonnucleoside reverse transcriptase inhibitors are substrates and potent inhibitors or inducers of the cytochrome P450 system. Many classes of recreational drugs, including benzodiazepines, amphetamines, and opioids, are also metabolized by the liver and can potentially interact with antiretrovirals. Controlled interaction studies are often not available, but clinically significant interactions have been observed in a number of case reports. Overdoses secondary to interactions between the "rave" drugs methylenedioxymethamphetamine (MDMA) or gamma-hydroxybutyrate (GHB) and PIs have been reported. PIs, particularly ritonavir, may also inhibit metabolism of amphetamines, ketamine, lysergic acid diethylmide (LSD), and phencyclidine (PCP). Case series and pharmacokinetic studies suggest that nevirapine and efavirenz induce methadone metabolism, which may lead to symptoms of opiate withdrawal. A similar interaction may exist between methadone and the PIs ritonavir and nelfinavir, although the data are less consistent. Opiate metabolism can be inhibited or induced by concomitant PIs, and patients should be monitored for signs of toxicity and/or loss of analgesia. PIs should not be coadministered with midazolam and triazolam, since prolonged sedation may occur.

CONCLUSIONS

Interactions between agents commonly prescribed for patients with HIV and recreational drugs can occur, and may be associated with serious clinical consequences. Clinicians should encourage open dialog with their patients on this topic, to avoid compromising antiretroviral efficacy and increasing the risk of drug toxicity.

Enantiomer analysis of a new street drug, 3,4-methylenedioxy-N-methyl-butanamine, in rat urine

A new street drug, 3,4-methylenedioxy-N-methyl-butanamine (MBDB), has been found in Japan recently. The stereoisomer monitoring and the urinary excretion kinetics are not determined in biological fluids even though abused MBDB is a racemic form [enantiomer ratio (-/+) = 1.00]. The present studies were done by high-performance liquid chromatography (HPLC) equipped with a chiral activity column at 40 degrees C using urine specimens from five Wistar rats. Urine samples were collected over six time intervals after a single oral administration of racemic MBDB (30 mg/kg). Unchanged MBDB and 3,4-methylenedioxybutanamine (BDB), an N-demethylated metabolite, were found in the rats' urine. Each enantiomer of MBDB and BDB was monitored (peak resolution > 1.00) by HPLC analysis within 30 min. For both MBDB and BDB, the (+)-isomers were excreted a little more than the (-)-isomers. The stereoselective disposition of BDB was more remarkable than that of MBDB and was observed in the urine throughout the study (p < 0.05). The urinary excretion of MBDB showed significant difference between the two enantiomers from 4 to 20 h (p < 0.05). The amount of MBDB excreted up to 24 h was 34.7+/-2.8% of the administered dose: 17.6+/-1.4% for (+)-isomer and 17.1+/-1.5% for (-)-isomer. The amount of BDB was 4.9+/-1.0%; 2.9+/-0.6% for (+)-isomer and 2.0+/-0.4% for (-)-isomer. The enantiomer ratio (-/+) of MBDB and BDB was 1.00 or a little smaller. The ratio (-/+) of MBDB changed from 1.00+/-0.02 to 0.88+/-0.09 by 24 h, and that of BDB from 0.68+/-0.03 to 0.78+/-0.02. The ratio (-/+) for MBDB and BDB accumulated up to 24 h was 0.97+/-0.01 and 0.70+/-0.06, respectively, and the total ratio (-/+) of the two substances was 0.93+/-0.02 (p < 0.05). These findings suggested that the stereoselective disposition of racemic MBDB was different from that of 3,4-dimethylenedioxyamphetamine and 3,4-dimethylenedioxymethamphetamine and was similar to that of methamphetamine.

Estimation of fetal exposure to drugs of abuse, environmental tobacco smoke, and ethanol

Many women worldwide use recreational drugs and alcohol. Details on the amounts and schedule of such exposures in pregnancy are often unreliable because of recall issues and shame and fears of legal action. Even when the report on maternal dose is correct, it does not necessarily reflect the amount reaching the fetus. Drugs of abuse accumulate in meconium and are incorporated into fetal hair on its growth. Recent work has documented the sensitivity and specificity of these assays for cocaine and other recreational drugs. Dose-response relationships between cocaine as measured in neonatal hair and head circumference or neurologic sequelae have been recently established. For ethanol, which cannot be measured in hair or meconium, accumulation of its fatty acid ethyl esters in meconium is emerging as a promising test for heavy maternal drinking in the second part of pregnancy. The identification of biologic markers of intrauterine exposure to xenobiotics will allow better understanding of etiology and dose-response relationships.

[Pharmacokinetic and toxicokinetic parameters of some drugs of abuse]

This article outlines the main pharmacokinetic and toxicokinetic parameters of selected addicting compounds often being abused. Described parameters affect the way the compounds behave in the body. The article shows the usual dosage and "therapeutic", toxic and fatal concentrations. Knowledge of described parameters is important in the process of detoxication in patients poisoned with this group of psychoactive compounds.

Alternative specimens for workplace drug testing

Recent advances in analytical techniques have enabled the detection of drugs and drug metabolites in alternative biological specimens for the purposes of workplace testing. A wide variety of specimens are available, each providing valuable information concerning prior or current drug use. The present focus is on oral fluid (saliva), hair, and sweat. An extensive evaluation by the Division of Workplace Programs of the Department of Health and Human Services is underway to determine the utility of these specimens in federally regulated programs. In future years, the testing of alternative specimens will expand our ability to understand the patterns of drug use and will become routine in all areas of forensic toxicology.

Detection time of drugs of abuse in urine

Estimating the detection time of a drug in urine is complex because of many different influencing factors and the lack of experimental data. Detection times vary depending on dose and route of administration, metabolism and characteristics of the screening and confirmation assays. Using a cut-off value of 1000 ng/mL, urinary samples can be positive for amphetamine for up to 5 days after intake of the drug. At the lower 300 ng/mL cut-off, amphetamine will be detectable one day longer. Very few data are available for designer amphetamines. After smoking one marijuana cigarette, THCCOOH (9-carboxy-delta 9 tetrahydrocannabinol) is detectable (using a screening cut-off of 50 ng/mL) for 2-4 days. More frequent use will be detectable for almost 1 month, exceptionally 3 months. Immunoassays to detect cocaine are targeted against the metabolite benzoylecgonine and use a cut-off of 300 ng/mL. An intravenous dose of 20 mg cocaine can be detected for 1.5 days. Street doses (administered via different routes) are detectable up to 1 week, and extremely high doses up to 3 weeks. Heroin rapidly metabolizes to 6-acetylmorphine and morphine. Immunoassays for heroin are calibrated with morphine but important cross-reactivity occurs and positive results must be confirmed by GC-MS. Experimental data for total morphine using a cut-off of 300 ng/mL suggest a detection time of 1 to 1.5 days for relatively low doses of heroin (3-12 mg) administered via i.v., IN or i.m. route.