Incorporation of five common hypnotics into hair after a single dose and application to a forensic case of drug facilitated crimes.

In order to obtain fundamental information on the disposition of hypnotics into hair after a single oral dose the quantitative hair analysis of triazolam (TZ), etizolam (EZ), flunitrazepam (FNZ), nitrazepam (NZ) and zolpidem (ZP) have been performed using a validated LC-MS/MS procedure. Hair specimens (straight, black) were collected from three subjects about one month and three months after a single 0.25 mg dose of TZ, 1 mg of EZ, 2 mg of FNZ, 5 mg of NZ and 10 mg of ZP tartrate. The subjects ingested just one out of five different hypnotics on each day, each of five days in turn. All ingested hypnotics have been detected in hair from each subject both one month and three months after intake, and their concentrations were in the range of 0.023-0.043 pg/hair strand (0.077-0.36 pg/mg) for TZ, 0.11-0.63 pg/hair strand (0.44-5.2 pg/mg) for EZ, 0.14-2.6 pg/hair strand (0.56-22 pg/mg) for FNZ, 0.33-1.7 pg/hair strand (1.3-17 pg/mg) for NZ and 20-40 pg/hair strand (120-270 pg/mg) for ZP. For FNZ and NZ, not only the parent drugs but also their metabolites, 7-amino-FNZ and 7-amino-NZ, were detected in the range of 2.3-9.2 pg/hair strand (9.2-82 pg/mg) and 2.4-9.1 pg/hair strand (8.0-55 pg/mg), respectively. The calculated incorporation ratios into hair against the dose were found to exhibit similarity between the four benzodiazepines. This finding suggests the ability to apply these quantitative data to approximately estimating the amounts of other benzodiazepines, which have similar chemical structures, in hair although it should be noted that the amounts of drugs in hair varies considerably depending on the hair color. On the other hand, the incorporation ratio of ZP showed 15-29 times higher than that of TZ, indicating that lipophilic ZP was more likely to incorporate into hair than benzodiazepines. In addition, the application of the present data to a drug-facilitated sexual assault was shown.

Effect of flunitrazepam as an oral hypnotic on 24-hour blood pressure in healthy volunteers.

PURPOSE: The present study was carried out in order to assess the effects of chronic administration of flunitrazepam (as an oral hypnotic) on 24-h blood pressure (BP) and heart rate (HR) in healthy young adults. MATERIALS AND METHODS: Following a 2-week placebo run-in period, 28 healthy volunteers (13 males and 15 females) between 21 and 30 years were randomized to receive either flunitrazepam 1 mg or placebo (both administered once a day in the evening) for 4 weeks in two cross-over periods; each separated by a 2-week placebo period. At the end of each study period, non-invasive 24-h BP and HR ambulatory monitoring was performed. RESULTS: Flunitrazepam produced a significant decrease in nighttime systolic blood pressure (SBP) (- 6.4 mmHg) and diastolic blood pressure (DBP) (- 4.1 mmHg) (both P < 0.05 vs placebo) without affecting nocturnal HR. During the morning hours, significantly higher values of SBP (+ 7.4 mmHg, P < 0.01), DBP (+ 3.4 mmHg, P < 0.05) and HR (+ 3.9 beats/min, P < 0.05) were observed in the flunitrazepam group compared to the placebo-treated group. No significant differences were noted between the two groups during afternoon and evening hours. CONCLUSIONS: These results suggest that chronic oral administration of 1 mg flunitrazepam as a hypnotic agent causes a significant nocturnal fall in BP and a transient rebound increase of both BP and HR at awakening in the morning. Mechanisms underlying these cardiovascular effects remain unclear, although the direct vasodilatory effect, which is typical of flunitrazepam (with consequent reflex counter-regulatory responses), and the attenuation of baroreflex sensitivity are likely to play a major role.

Amnestic drugs in the odor span task: Effects of flunitrazepam, zolpidem and scopolamine.

The odor span task is an incrementing non-matching-to-sample procedure designed to provide an analysis of working memory capacity in rodents. The procedure takes place in an arena apparatus and rats are exposed to a series of odor stimuli in the form of scented lids with the selection of new stimuli reinforced. This procedure makes it possible to study drug effects as a function of the number of stimuli to remember. In the present study, the non-selective positive allosteric GABAA receptor modulator flunitrazepam impaired odor span performance at doses that did not affect a control odor discrimination. In contrast, the alpha-1 selective positive GABAA receptor modulator zolpidem and the cholinergic receptor antagonist scopolamine only impaired odor span at doses that produced more global impairment, including decreased accuracy in the control discrimination and increased response omissions in the both the odor span and control discrimination procedures. Even though the effects of flunitrazepam were selective to odor span performance, they did not depend on the number of stimuli to remember-the same degree of impairment occurred regardless of the memory load. These findings suggest that flunitrazepam interfered selectively with conditional discrimination performance rather than working memory and tentatively suggest that flunitrazepam's selective effects in the odor span task relative to the control odor discrimination are mediated by one or more non-alpha1 GABAA receptor subtypes.

Development of a sedation protocol using orally administered tiletamine-zolazepam-acepromazine in free-roaming dogs.

OBJECTIVE: To investigate the sedative effects in dogs of tiletamine-zolazepam-acepromazine (TZA) or ketamine-flunitrazepam (KF) administered orally and to evaluate the effectiveness of encapsulated TZA for capturing free-roaming dogs. STUDY DESIGN: Experimental study followed by a field trial. ANIMALS: Six research dogs and 27 free-roaming dogs. METHODS: In a pilot study, six research dogs were administered liquid TZA (20 mg kg-1 tiletamine-zolazepam and 2 mg kg-1 acepromazine) or liquid KF (50 mg kg-1 ketamine and 2 mg kg-1 flunitrazepam) orally: treatment 1, forcefully squirting liquid medication into the mouth; treatment 2, encapsulating liquid medication for administration in canned food; treatment 3, administering liquid medication mixed with gravy. Sedation was scored. A follow-up field trial attempted capture of 27 free-roaming dogs. RESULTS: In the pilot study, the median time (range) to lateral recumbency (% dogs) after TZA administration was: treatment 1, 47.5 (35-80) minutes (67%); treatment 2, 30 (15-65) minutes (83%); and treatment 3, 75 (45-110) minutes (100%). No dogs in KF treatment 2 or 3 achieved lateral recumbency. Based on these results, 20 free-roaming dogs were offered encapsulated TZA in canned food: TZ (20 mg kg-1) and acepromazine (2 mg kg-1). Of these, no further drugs to four dogs (one dog captured), 10 dogs were administered a second dose within 30 minutes (five dogs captured) and six dogs were administered TZ (5 mg kg-1) and xylazine (1.1-2.2 mg kg-1) intramuscularly by blow dart (six dogs captured). Seven dogs were initially offered twice the TZA dose (five dogs captured). In total, 63% free-roaming dogs were captured after administration of encapsulated TZA in canned food. CONCLUSIONS AND CLINICAL RELEVANCE: Oral administration of encapsulated TZA in canned dog food can aid in the capture of free-roaming dogs, but additional drugs may be required. The sedation onset time and medication palatability influenced the capture rate.

Use of GABAergic sedatives after subarachnoid hemorrhage is associated with worse outcome-preliminary findings.

STUDY OBJECTIVE: Recent experimental evidence identified GABAergic sedation as a possible cause for deprived neuroregeneration and poor outcome after acute brain injury. Patients with aneurysmal subarachnoid hemorrhage are often sedated, and GABAergic sedation, such as midazolam and propofol, is commonly used. DESIGN: Retrospective cohort study based on a prospectively established database. SETTING: Single-center neurointensive care unit. PATIENTS: Twenty-nine patients after subarachnoid hemorrhage. INTERVENTION: Noninterventional study. MEASUREMENTS: The relationship between mean GABAergic sedative dose during the acute phase and outcome after 6 months according to the Glasgow Outcome Scale, and initial Glasgow Coma Scale was investigated. MAIN RESULTS: Use of GABAergic sedatives was negatively correlated with Glasgow Outcome Scale (r2=0.267; P=.008). Administration of sedatives was independent of the initial Glasgow Coma Scale. GABAergic sedatives flunitrazepam, midazolam, and propofol were used differently during the first 10 days after ictus. CONCLUSION: Administration of GABAergic sedation was associated with an unfavorable outcome after 6 months. To avoid bias (mainly through the indication to use sedation), additional experimental and comparative clinical investigation of, for example, non-GABAergic sedation, and clinical protocols of no sedation is necessary.

Good clinical outcome after accidental intra-arterial injection of flunitrazepam tablets in 16 drug abusers with critical limb ischaemia.

OBJECTIVES: Inadvertent intra-arterial injection of flunitrazepam tablets intended for intravenous use by drug abusers has devastating effects. We report here on the clinical outcome of 16 drug abusers developing critical limb ischaemia after flunitrazepam injection. METHODS: Treatment combined immediate analgesia and anticoagulation, long-lasting local thrombolysis and vasodilatation, antibiotic prophylaxis, and physical mobilization. The immediate bolus injection of 5,000 IU heparin was followed by a continuous heparin infusion up to the target partial thromboplastin time. Under arteriographic control local intra-arterial infusion with alternating 4-h cycles of 5 mg recombinant tissue plasminogen activator followed by 5 µg prostaglandinE1 (PGE1) was performed for 24-48 hours. Subsequently, 60 µg PGE1 was applied once daily. RESULTS: Drug abusers, having been injected with 4-30 mg flunitrazepam, were treated 3-72 hours after the accident, with six of them not being treated until after 24 hours. All showed a high tissue ischaemia score. At the time of being discharged from hospital 13 patients had a normal extremity. In one patient, first receiving treatment 72 hours after injection, minor amputation of fingers was necessary. The life of the patient who injected 30 mg flunitrazepam in the leg was saved after hip disarticulation. One patient developed neurological dysfunction in the affected toes. CONCLUSIONS: Intensive treatment after inadvertent intra-arterial drug injection normalized the affected extremity in most drug abusers, even after the late onset of therapy.

[Perioperative management of off-pump CABG for a 93-year-old man].

In recent years, the aging population has been growing, and the operative techniques and anesthetic methods have advanced. With these developments and medical support, the number of operations on very elderly patients has been increasing. We report the perioperative management of off-pump CABG for a 93-year-old man. When the heart was displaced during the operation, hypotension was induced and a marked reduction of his bispectral index (BIS) to "1" appeared. During the perioperative period, the patient developed delirium that was difficult to manage, but he was discharged from the hospital without any complications on POD 21. As part of the perioperative management, intraoperative cerebral circulatory management with attention to cerebral perfusion and prevention of postoperative delirium is crucial.

Chemical submission to commit robbery: a series of involuntary intoxications with flunitrazepam in Asian travellers in Brussels.

Between January 17, 2003 and August 29, 2003, the Emergency Department admitted a patient who had been surreptitiously intoxicated and robbed of his valuables every Friday. The first cases were considered anecdotal, but criminal activity was rapidly suspected. The cohort includes 16 male Asian patients aged 28-50 years. All the victims had just arrived in Brussels through one of the main rail station of the town and were admitted via the emergency ambulance service from different locations in the centre of Brussels around the CHU Saint-Pierre Hospital. Haemodynamic parameters upon admission were within normal limits. The Glasgow Coma Scale was equal or higher than 9/15 in 14 of the 16 victims. Toxicology screening obtained in 12 patients revealed the presence of flunitrazepam, which was further quantified at levels ranging from 21 to 75 µg/l. One of the Japanese patients, who returned to Belgium afterwards for professional reasons, was approached by the police and accepted to press charges. This allowed the police to investigate and send undercover agents to the railway station on Friday afternoons and evenings. They found a person who was offering welcome cookies to Asian travellers. He arrived from Amsterdam and returned once his crime was committed. Flunitrazepam is well known as a rape drug. We report a series of victims in whom flunitrazepam was used to facilitate robbery.

[Acute right heart failure after intravenous application of heroin and flunitrazepam]. / Akutes Rechtsherzversagen nach intravenöser Applikation von Heroin und Flunitrazepam.

HISTORY: A 32-year-old woman was admitted to the emergency department because of acute dyspnea and syncope. A few minutes before the onset of symptoms, she had self-administered an intravenous injection of one gram of heroin combined with grinded flunitrazepam tablets. INVESTIGATIONS: Signs of acute cor pulmonale were detected on transthoracic echocardiography despite lack of pulmonary embolism in computed tomography. It was assumed that microembolisms were the cause of acute pulmonary hypertension after intravenous injection of heroin and flunitrazepam. TREATMENT AND COURSE: Because of lack of thrombus in CT scan therapeutic anticoagulation with unfractionated heparin and oxygen insufflation was initiated resulting in rapid improvement of oxygen saturation and blood pressure. On the following day pulmonary pressure in transthoracic echocardiography was already decreased significantly. Without signs of deep venous thrombosis in duplex scan and only a marginal sub segmental perfusion deficit in ventilation-perfusion-scintigraphy therapeutic anticoagulation was recommended for three months. CONCLUSION: The most likely cause of micro embolisms in this case are particles of talc, which are often used to cut heroin, or the microcrystalline cellulose used in tablets. There have been reports of tissue necrosis due to arterial embolism/vasospasm by crystalloid or oily substances (embolia cutis medicamentosa) in the extremities after intraarterial injection of grinded flunitrazepam tablets. Therefore it seems plausible that intravenous application may cause a serve but transient deficit of perfusion in pulmonary circulation.

Effects of chronic flunitrazepam treatment schedule on therapy-induced sedation and motor impairment in mice.

BACKGROUND: The aim of the present study was to examine whether different treatment schedules could be associated with tolerance development to the ataxic and sedative effects of flunitrazepam in mice. METHODS: Effects of repeated flunitrazepam administration were studied in the rotarod and the chimney test for motor coordination and in a photocell apparatus for locomotor activity in mice. Flunitrazepam doses varied in particular types of injections or in different experiment duration periods. RESULTS: Repeated flunitrazepam administration (1 mg/kg, sc and 2 mg/kg, ip) for 8 consecutive days induced tolerance to the motor impairing effects of flunitrazepam in mice, both in the rotarod and the chimney test. In turn, no tolerance developed to sedative flunitrazepam effects, regarding either dose level, injection type or treatment duration. CONCLUSIONS: Those findings confirmed the previous observations that tolerance to benzodiazepines was not simultaneous for each pharmacological property of the drugs. Interestingly enough, an acute dose of flunitrazepam (1 mg/kg, sc) in our study enhanced locomotor activity of mice.

Differential effects of short- and long-term zolpidem treatment on recombinant α1ß2γ2s subtype of GABA(A) receptors in vitro.

AIM: Zolpidem is a non-benzodiazepine agonist at benzodiazepine binding site in GABA(A) receptors, which is increasingly prescribed. Recent studies suggest that prolonged zolpidem treatment induces tolerance. The aim of this study was to explore the adaptive changes in GABA(A) receptors following short and long-term exposure to zolpidem in vitro. METHODS: Human embryonic kidney (HEK) 293 cells stably expressing recombinant α1ß2γ2s GABA(A) receptors were exposed to zolpidem (1 and 10 µmol/L) for short-term (2 h daily for 1, 2, or 3 consecutive days) or long-term (continuously for 48 h). Radioligand binding studies were used to determine the parameters of [(3)H]flunitrazepam binding sites. RESULTS: A single (2 h) or repeated (2 h daily for 2 or 3 d) short-term exposure to zolpidem affected neither the maximum number of [(3)H]flunitrazepam binding sites nor the affinity. In both control and short-term zolpidem treated groups, addition of GABA (1 nmol/L-1 mmol/L) enhanced [(3)H]flunitrazepam binding in a concentration-dependent manner. The maximum enhancement of [(3)H]flunitrazepam binding in short-term zolpidem treated group was not significantly different from that in the control group. In contrast, long-term exposure to zolpidem resulted in significantly increase in the maximum number of [(3)H]flunitrazepam binding sites without changing the affinity. Furthermore, long-term exposure to zolpidem significantly decreased the ability of GABA to stimulate [(3)H]flunitrazepam binding. CONCLUSION: The results suggest that continuous, but not intermittent and short-term, zolpidem-exposure is able to induce adaptive changes in GABA(A) receptors that could be related to the development of tolerance and dependence.

Double-balloon endoscopy versus magnet-imaging enhanced colonoscopy for difficult colonoscopies, a randomized study.

BACKGROUND AND STUDY AIMS: Studies have estimated that failure of cecal intubation occurs with conventional colonoscopy in up to 10 % of cases. Double-balloon endoscopy (DBE) systems, magnetic endoscope imaging (MEI), and transparent cap have been shown to improve success rates for colonoscopy. This study evaluated the utility of DBE for complete examination of the colon compared with MEI plus cap (MEI-Cap) after incomplete or technically difficult colonoscopy in a randomized comparative manner. PATIENTS AND METHODS: A total of 94 patients with incomplete or technically difficult colonoscopy were randomly assigned to receive either DBE (n = 47) or colonoscopy with MEI-Cap (n = 47). The primary end point was cecal intubation rate within 30 minutes. Secondary end points included intubation time, pain score using a visual analog scale, abdominal pressure attempts, doses of sedative medication, and changes in patient position during colonoscopy. RESULTS: Patient characteristics were comparable in both groups. Cecal intubation rate within 30 minutes was significantly higher for DBE (45 /47, 95.7 %) than for MEI-Cap (34 /47, 72.3 %) (P = 0.0049). Mean time to reach the cecum was significantly lower in the DBE group (13.0 ±â€Š5.3 minutes) than in the MEI-Cap group (16.4 ±â€Š4.8 minutes; P = 0.0003). No complications were encountered in either group.   CONCLUSION: DBE is more useful for complete examination of the colon than MEI-Cap in patients with incomplete or technically difficult colonoscopy.

Effects of pregnanolone and flunitrazepam on the retention of response sequences in rats.

Neuroactive steroids produce effects similar to other GABA(A) modulators (e.g., benzodiazepines and barbiturates) and have a large therapeutic potential; however, a greater understanding of the effects of these substances on learning and memory is needed. To specifically assess the effects of a neurosteroid on memory, pregnanolone (1-18 mg/kg) was administered to male Long-Evans rats responding under a repeated acquisition and delayed-performance procedure in which different 4-response sequences were acquired and then retested after varying delays. Responding was maintained under a second-order fixed-ratio (FR) 2 schedule of food reinforcement, and incorrect responses (errors) produced a 5-sec timeout. For comparison purposes, both a high (flunitrazepam) and low efficacy agonist/antagonist (flumazenil) of the GABA(A) receptor complex were also administered both alone and in combination. Retention of each sequence was quantified as percent savings in errors-to-criterion and this dependent measure was shown to be sensitive to increases in delay. When administered 15 min prior to the end of either a 30- or 180-minute delay, pregnanolone produced both dose- and delay-dependent decreases in percent savings, response rate and accuracy; this effect was selective in that decreases in retention occurred at doses lower than those that disrupted response rate or accuracy. Flunitrazepam (0.056-1mg/kg) produced similar disruptions in retention and these disruptions were antagonized by 5.6 mg/kg of flumazenil. Both an ineffective (0.056 mg/kg) and an effective (0.18 mg/kg) dose of flunitrazepam also potentiated the dose- and delay-dependent disruptions in retention produced by pregnanolone. These data indicate that the neurosteroid pregnanolone disrupts retention in a manner similar to the benzodiazepine flunitrazepam, and suggests that the interaction of flunitrazepam and pregnanolone on retention may be mediated by the GABA(A) receptor complex.

Successful thrombolysis and spasmolysis of acute leg ischemia after accidental intra-arterial injection of dissolved flunitrazepam tablets.

A 37-year-old man with known intravenous drug abuse presented in the surgical ambulatory care unit with acute leg ischemia after accidental intra-arterial injection of dissolved flunitrazepam tablets into the right femoral artery. A combination of anticoagulation, vasodilatation, and local selective and superselective thrombolysis with urokinase was performed to salvage the leg. As a result of the severe ischemia-induced pain, the patient had to be monitored over the complete therapy period on the intensive care unit with permanent administration of intravenous fluid and analgetics. We describe the presenting symptoms and the interventional technique, and we discuss the recent literature regarding the management of accidental intra-arterial injection of dissolved flunitrazepam tablets.

Superadditive effects of ethanol and flunitrazepam: implications of using immunopharmacotherapy as a therapeutic.

While benzodiazepine intoxication alone may elicit sedative and antianxiety effects, alcohol coingestion greatly amplifies this central nervous system depression. As a result, this drug combination gained notoriety for its role in cases of facilitated sexual assault and fatal overdose. We previously validated the ability of the novel antiflunitrazepam monoclonal antibody (mAb) RCA3A3 to bind flunitrazepam (FLU) in vivo and block FLU-induced impairment of locomotion and memory. A therapeutically relevant application of this high affinity mAb (K(d,app) = 200 nM), however, is to the more tenuous indication of flunitrazepam (FLU) and alcohol cointoxication. Employing a murine behavioral model, passive immunization with mAb RCA3A3 before injection of ethanol (EtOH: low-dose, 1 g/kg, or high-dose, 1.5 g/kg), FLU (0.06 mg/kg), or a cocktail of both drugs offered partial to full restoration of motor activity levels in co-drug treated and FLU-treated mouse groups (n = 12), respectively. Whereas all drug treatments left contextual learning intact, auditory cued learning was severely disrupted. Prophylactic administration of mAb RCA3A3 prevented this deficit in cued learning in FLU-treated mice but not in the FLU- and EtOH-treated mice, in which co-drug exposure exacerbated the impairment in cued fear conditioning. To substantiate this finding, a dose-response study was performed, and the changes in locomotor activity incurred by different FLU (low-dose, 0.06 mg/kg, or high-dose, 0.09 mg/kg), EtOH (1.0 g/kg, 1.5 g/kg), and mAb RCA3A3 (14.5 mg/kg, 21.8 mg/kg) dose combinations illustrated the potentiation in motor effects by concomitant exposure to FLU and EtOH. Thus, motor activity and fear conditioning results demonstrated that both the amount of FLU left unbound by antibody and the pharmacological additivity between FLU and EtOH, a GABA mimetic, were limiting factors in the therapeutic efficacy of mAb RCA3A3. In sum, our study highlights the complex nature of psychomotor impairment upon co-drug versus singular drug exposure, which may pose a unique challenge to therapeutic treatment.

A prospective naturalistic multicentre study of intravenous medications in behavioural emergencies: haloperidol versus flunitrazepam.

A prospective naturalistic multicentre study for deep sedation was conducted in intensive care with continuous electrocardiogram (ECG) monitoring. Clinical purpose was enough sedation, which made uncooperative and disrupted patients receive brain computed tomography (CT), magnetic resonance imaging (MRI), or fluid therapy, with minimum drug doses. A first infusion was either haloperidol (HAL group) or flunitrazepam (FNP group). If enough sedation was not achieved, a second infusion, which was the opposite drug to the first infusion, was given. The proportion requiring a second infusion was higher in the HAL group than in the FNP group (82% vs. 36%, P<0.0001). The mean reduction of the Excited Component for Positive and Negative syndrome scale at 15 min was greater for the FNP first group (FNP+HAL group) than the HAL first group (HAL+FNP group) (68% [S.D. 17] vs. 54% [S.D. 31], P=0.02). The mean dose of flunitrazepam in the HAL+FNP group was significantly lower than that in the FNP+HAL-group (1.3 mg vs. 3.5 mg, P=0.0003). Thus, in terms of monotherapy and speed of action, flunitrazepam has advantages over haloperidol as a first infusion for deep sedation. Regarding drug dosages, haloperidol has an advantage over flunitrazepam as a first infusion in safety.

Flunitrazepam in combination with alcohol engenders high levels of aggression in mice and rats.

RATIONALE: Higher doses of benzodiazepines and alcohol induce sedation and sleep; however, in low to moderate doses these drugs can increase aggressive behavior. OBJECTIVES: To assess firstly the effects of ethanol, secondly the effects of flunitrazepam, a so-called club drug, and thirdly the effects of flunitrazepam plus alcohol on aggression in mice and rats. METHODS: Exhaustive behavioral records of confrontations between a male resident and a male intruder were obtained twice a week, using CF-1 mice and Wistar rats. The salient aggressive and non-aggressive elements in the resident's repertoire were analyzed. Initially, the effects of ethanol (1.0g/kg), and secondly flunitrazepam (0; 0.01; 0.1; and 0.3mg/kg) were determined in all mice and rats; subsequently, flunitrazepam or vehicle, given intraperitoneally (0; 0.01; 0.1; and 0.3mg/kg) was administered plus ethanol 1.0g/kg or vehicle via gavage. RESULTS: The most significant finding is the escalation of aggression after a moderate dose of ethanol, and a low dose of flunitrazepam. The largest increase in aggressive behavior occurred after combined flunitrazepam plus ethanol treatment in mice and rats. CONCLUSIONS: Ethanol can heighten aggressive behavior and flunitrazepam further increases this effect in male mice and rats.

Urinary detection times and excretion patterns of flunitrazepam and its metabolites after a single oral dose.

We investigated the excretion profiles of flunitrazepam metabolites in urine after a single dose. Sixteen volunteers received either 0.5 or 2.0 mg flunitrazepam. Urine samples were collected after 2, 4, 6, 8, 12, 24, 48, 72, 96, 120, 240, and 336 h. Samples were screened using CEDIA (300 microg/L cutoff) and quantitated using liquid chromatography-tandem mass spectrometry. The cutoff was 0.5 microg/L for flunitrazepam, N-desmethylflunitrazepam, 7-aminoflunitrazepam, 7-aminodesmethylflunitrazepam, 7-acetamidoflunitrazepam, and 7-acetamidodesmethylflunitrazepam. None of the subjects receiving 0.5 mg were screened positive, and only 23 of 102 samples from the subjects given 2.0 mg were positive with CEDIA. The predominant metabolites were 7-aminoflunitrazepam and 7-aminodesmethylflunitrazepam. For all subjects given the low dose, 7-aminoflunitrazepam was detected up to 120 h, and for two subjects for more than 240 h. Seven subjects given the high dose were positive up to 240 h for 7-aminoflunitrazepam. We conclude that the ratio 7-aminodesmethylflunitrazepam to 7-aminoflunitrazepam increased with time, independent of dose, and may be used to estimate the time of intake. For some low-dose subjects, the metabolite concentrations in the early samples were low and a chromatographic method may fail to detect the intake. We think laboratories should consider this when advising police and hospitals about sampling as well as when they set up strategies for analysis.